Lattice beam technical manual - Metsec Lattice Beams...

CI/SfB (28) Hh2

January 2016 1

Lattice beam technical manual

Joists, trusses and complete frame installation service

Contents

MLB : Investing in quality and service 3-4

Installation 5

Product range 6-10

Features and benefits 6-7

Product range Heavy duty range

8-9 10

Roof beams 11-18

Metal roof systems 11-12

Traditional roof systems 13

Green roof systems 14

Complete lightweight systems 15

Over-roof systems 16

Eaves cantilever systems 17-18

Ceiling and service supports 19-20

Ceiling and service support systems 19

Walk on ceiling systems 20

Floor beams 21-22

Traditional floor systems 21

Mezzanine floor systems 22

Fixing details 23-26

Typical fixing details 23-26

Chord and bridging details 27-28

Chord details 27

Bridging details 28

Design examples and load tables 29-35

Design examples 29-32

Load tables - Parallel beams 33-35

Services and design software 36-37

Services and general notes 36 Software 37

2

Quality and service Quality and service

Investing in quality and service

Metsec plc

Metsec plc is the UK’s largest specialist cold

roll-forming company, providing structural steel

components for the UK construction and

manufacturing industries. We have been

established for over 75 years and are based in

Oldbury in the West Midlands.

Today, Metsec are part of the Profilform Division

of voestalpine - the world’s largest manufacturer

of cold roll-formed sections, with a global network

producing over 800,000 tonnes of cold rolled steel

per annum.

We focus on adding value through expert design,

precision manufacturing and on-time, in-full

product delivery. Our aim is to provide excellent

service and quality products that offer our

customers cost effective solutions.

Please Note

As of April 2012, Metsec Lattice

Beams Ltd are no longer part of the

Metsec plc group. We are now an

independent trading company.

Metsec Lattice Beams

Lightweight steel lattice beams were first

introduced by Metsec in the 1950’s and their

inherent advantages very quickly established the

product as the first choice for structurally sound,

cost effective construction.

Since this introduction, the Metsec policy of

continual research and development has ensured

that quality and technical properties have

improved over the years and availability of type

has increased in parallel with development in

building technology and architectural styles.

Metsec Lattice Beams Ltd offer a wide range of joist

and truss solutions pre-engineered off site. We can

achieve spans of up to 40m and all of our designs

give optimal levels of structural performance in

roof, floor or any other application where light

weight and long span performance is important.

All sections are designed in accordance with BS

5950-5:1998.

Quality

MLB operates strict design and quality

procedures through a Quality Management

System which covers both our design and

manufacturing operations.

This commitment to quality ensures that we

provide the highest levels of performance

throughout our operations, ensuring the highest

level of customer satisfaction.

Design

Our market-leading LatticeSPEC design software

provides cost effective solutions to maximise the

design efficiency of structures. Comprehensive

technical support is provided by our design office.

The latest version of LatticeSPEC offers the unique

advantage of producing complete profiles/sections

of joists and trusses in .dxf format, saving the professional

team valuable time when specifying our products.

For full details on our technical support service

and how to obtain a free copy of LatticeSPEC

please refer to page 39.

Re-use and recycling

Steel is one of the World’s most recycled materials. According to the British Constructional Steelwork Association (BCSA), recovery rates for steel components from building demolition sites are 84% for recycling and 10% for re-use*. This gives a total potential recovery and re-use factor of steel from buildings of an incredible 94%. * BCSA publication no. 35/03

3

Quality and service Product range

CE Marking Accreditation

Metsec Lattice Beams Limited has attained CE marking accreditation to Execution Class 3 (EXC 3) of BS EN 1090-2.

CE Marking Accreditation to Execution Class 3 (EXC 3) of BS EN 1090-2.

Since July 1st 2014 CE marking became compulsory for all manufacturers of structural steel components in the UK.

Metsec Lattice Beams Limited's Factory Control Production (FPC), management systems and welding procedures have all been certified by BSI to comply with stringent CE marking standards.

CE marking is a regulatory mark applied by the manufacturer. It is a declaration that the product conforms with the relevant technical specifications and that the required assessment procedures have been complied with.

CE marking accreditation demonstrates our commitment to delivering premium quality products to the market.

4

Quality and service Product range

Installation Service As well as being one of the UK’s largest manufacturers and

suppliers of lightweight lattice beams and trusses we also provide a complete design and installation service. Furthermore if our Lattice Beams are part of your specification we can offer the installation of the complete ‘Steelwork Package’ inclusive of cladding and roofing.

Our highly skilled and experienced engineers will work closely with your chosen architect/structural engineer to create a design that meets and exceeds all criteria and ensures your project gets delivered on time and within budget. This attention to quality runs through to the manufacture and installation. With significant experience of working closely with architects, designers and contractors, Metsec Lattice Beams can advise on the best and most efficient way to deliver your project. From developing installation plans, fabrication to the highest standards, logistics, delivery and site management, Metsec Lattice Beams is your preferred partner.

We ensure that all lattice beam and associated ancillary steel installations comply with engineer’s drawings and that the final installation is checked and certified. We are CE accredited and CHAS approved confirming our commitment to provide a quality service including final installation. All site work conforms to latest health and safety requirements including method statement and personnel training.

Proud to be a trusted partner to many of the UK’s leading construction companies, Metsec Lattice Beams has a strong track record in the safe delivery and installation of lattice beams across the UK and Europe for public and private sector clients.

To take advantage of our experienced design and installation service:

• Email your project details to [email protected]

• Complete our online request form

• Phone our technical advisory service directly on +44 (0)1902 408011

We are members of:

5

mailto:[email protected]

http://www.metseclatticebeams.com/contact/

Product range Product range

6 6

Features and benefits

Metsec lattice beams are designed and

manufactured to BS 5950-1: 2000 and 5: 1998 and

are formed from two cold rolled chord sections

with a central web joining the two together.

Typical profiles are shown on page 8-9. The chord

sections are all formed from high yield steel to BS

EN 10149-2: 1996 and have a minimum yield

strength of 355N/mm².

The web members are usually constructed from

solid bar on the smaller joists or hollow section for

the deeper joists and trusses. These are joined to

the chord sections by CO2 shielded arc welding in

a pre-set jig to ensure dimensional accuracy.

This process allows for the design and

manufacture of a vast range of profiles, from

simple parallel joists through to complex double

curve, wave trusses, to suit almost any

application.

Long span

A typical Metsec lattice beam can weigh up to

50% less than its hot rolled counterpart and yet

still achieve spans of up to 40m without the need

for intermediate support columns - which can

allow designers greater flexibility when working

to optimise internal space.

Internal space can also be optimised by passing

services through the web of the lattice rather than

having to suspend them underneath causing a

significant loss of headroom.

Services - excellent head height

The open web configuration of Metsec lattice

beams allows for the simple passage of services

through the web lacings. However, the web

lacings will not necessarily align unless this is

specifically requested.

Where special duct openings are required these

should be positioned near the centre of the beam

where shear is less critical.

Please consult the Metsec Lattice Beam Technical

Department for further information.

6


7 7

Optimised wall/ceiling junctions

Due to the slim profile offered by Metsec lattice

beams’ excellent strength to weight ratio, beams

can be incorporated at the head of partitioning

and drylining systems without any requirement

for separate boxing in or encasement.

This allows continuous and parallel studwork to

full ceiling height, simplifying and accelerating

installation, maximising use of space and

optimising aesthetics.

Pre-engineered offsite - to ease site access

Where site access is a consideration, bolted joints

can be used. The joists are then assembled on site

using H.T. grade 8.8 bolts to join the sections.

Flush site joints to the top and/or bottom chords

are also available.

Factory joints may occasionally be incorporated

into joists. They will always consist of an

appropriate jointing arrangement with a full

profile fillet weld.

Finish – as flexible as your design

All Metsec lattice beams are supplied shot blasted

and factory finished with a Zinc Phosphate primer

as standard. Other painted finishes, including any

standard RAL colour, are available upon request.

This feature is particularly important if it is

desired to leave the lattice members exposed as

part of a ‘feature’ internal roof structure.

A hot-dipped galvanised finish is also available.

This is recommended for cold roofs and roofs with

limited access or exposed locations.

Timber - for rapid, secure fixings

Flush fitting standard ‘Vac-Vac WR’ treated timber

can be supplied if required in the top and/or

bottom chords of all beams. The timber is rigidly

attached to the chords by shot-fired pins at

600mm staggered centres. This offers a simple

fixing medium for certain floor/roof finishes,

timber firrings and/or plasterboard ceilings.

7


8 8

Product range

Parallel beam

Roofs – suitable for use with flat roofs or sloping roofs

where the lattice beams can be laid to falls. They can

also be used as long span purlins and are suitable for use

with most external finishes from lightweight metal

sheeting through to heavier constructions with tiles on

battens or decking.

Floors – suitable for use as joists in all types of flooring

including timber, pre-cast concrete slabs or profiled

metal decking with in-situ poured concrete.

Pitched truss

Pitched trusses are suitable for all types of duo-pitch roof

construction and can be used with most external finishes

from lightweight metal sheeting through to heavier

constructions with tiles on battens or decking.

Tapered truss

Tapered trusses are suitable for all types of mono-pitch

roof construction. They can be used with most external

finishes from lightweight metal sheeting through to

heavier constructions with tiles on battens or decking.

Inverted truss

Inverted trusses are generally used on low pitched

roofing with timber or metal decking and built up

finishes. When used in conjunction with Metsec

Z-section purlins the design of deep valley gutters can

be simplified.

Parallel pitched beam

Parallel pitched beams are suitable for all types of duo-

pitch roof construction providing extra headroom over

that afforded by the pitched truss. They can be used

with most external finishes from lightweight metal

sheeting through to heavier constructions with tiles on

battens or decking.

8


9 9

Curved truss

Curved trusses can provide an aesthetically enhanced

roof profile. When used with a standing seam roof this

type of construction is easy to detail and install giving a

very low maintenance roof.

Curved beam

Curved beams provide an aesthetically enhanced roof

profile construction providing extra headroom over that

afforded by the curved truss. When used with a standing

seam roof this type of construction is easy to detail and

install giving a very low maintenance roof.

Double curved (wave) truss

Double curved trusses provide an ideal solution for the

designer working with modern multi-curved roof

structures. When used in conjunction with Metsec SFS

framing system the structure can be built to a constant

datum and can be used with all typical external finishes

Inverted curved truss

Inverted curved trusses offer designers a simple solution

when specifying a single curve roof structure. This can

be used to enhance the appearance of roof structures and

is frequently specified with standing seam roofing to

create a smooth appearance.

In many of the applications listed above Metsec Z-section purlins

provide an excellent design solution to carry the external finish.

Similarly the wide range of Metsec mezzanine floor C-sections can

provide a range of system solutions for the designer.

9


10

10

Heavy duty range

Metsec lattice beams are the UK’s largest

specialist manufacturer of steel lattice beams and

trusses. All beams are detailed and fabricated to

suit the clients requirements.

Typical truss profiles are shown on the previous

pages, however, we are not restricted to these

and the potential shape and scope of the lattice

trusses is endless. On many occasions the truss

profile is developed to suit Architectural

requirements.

Our 3000m2 manufacturing facility has been

custom developed and laid out in order to

determine the most efficient flow of materials.

This ensures not only highly efficient production

methods but improved levels of consistency and

quality.

Trusses are regularly produced with span of up to

40m and depths up to 4.5m.

Lattice beams are not only used for roof and floors

but are also ideal for long span ceiling supports, pipe bridges and service support gantries.

Lattice beams and trusses can be fabricated to

customers design and specifications. We

regularly model and fabricate lattice beams and

trusses using SHS, RHS and UC sections.

All fabrications are covered with our CE marking

accreditation. This accreditation allows

fabrications of up to and including

Execution Class 3 (EXC 3) of BS EN 1090-2.

10

11

11

Roof beams Roof beams

Metal roof systems

Metsec lattice beams can offer the ideal solution

for supporting a wide variety of roofing systems

due to their excellent strength to weight ratio.

A typical Metsec lattice beam can weigh up to

50% less than its hot rolled counterpart and yet

still achieve spans of up to 40m without the need

for intermediate support columns – which can

allow designers greater flexibility when working

to optimise internal space.

Internal space can also be optimised by passing

services through the web of the lattice rather than

having to suspend them underneath causing a

significant loss of headroom.

Similarly their aesthetic properties mean that they

can be supplied painted and left exposed as part

of a ‘feature’ internal roof structure.

In addition to the direct reduction of the

environmental footprint of a construction project

by virtue of their lighter weight, lattice beams can

also help to reduce the environmental footprint of

the project by using off-site fabrication to speed

up the construction process of the roof as the

lighter sections can generally be transported and

handled more efficiently on site.

Leasowes Medical Centre, West Midlands

Curved truss with structural deck

Metsec curved trusses can be used to support

structural decks with a suspended ceiling.

The natural open web of the truss allows for the

simple passage of services.

11

12

12


Parallel beam laid to fall

Metsec parallel beams can be used to support Z-section purlins

bolted to cleats pre-welded to the top chord of the beam. Liner tray,

insulation and metal deck provide the weather-proof layer and are

fixed to the Z-section purlins.

Pitched truss with flush-fitting Z-section purlins

Metsec pitched trusses are supported on a hot rolled steel structural

frame. Z-section purlins are fitted flush to the top chord of the

pitched trusses to support standing seam roof, or similar.

Flush fitting Z-section purlins are often used to minimise the overall

construction depth of the roof.

Vauxhall Sales Centre, West Midlands

Staplehurst Medical Centre, Kent

12

13

13


Traditional roof systems

Parallel beam used as purlin

Metsec parallel beams can be

used as long span purlins

supported on load bearing

masonry walls. In this

application timber firrings are

fixed directly to flush fitting

timber inserts in the top chord

of the beam. Timber roof rafters

are then fixed to the timber

firrings to support counter

battens, underlay, tiling battens

and tile or slates.

Firrings

by others

Timber insert

for nailability

Pitched truss used to support

timber purlins

Traditional timber purlins can

be supported on a Metsec

pitched truss. Ply or similar

sheathing is then used to

support weatherproofing layers

of battens, underlay and roof

tiles or slates.

13

14

14


Green roof systems

Parallel beams used to support

steel decking with green roof

surfacing

Metsec parallel beams can be used

to support a structural deck,

membrane, substrate and Sedum

roof.

These beams can be up to 50%

lighter than hot rolled beams and

use far less steel with considerably

less environmental impact than

other systems.

Smithswood School, Solihull

14

15

15


Complete lightweight systems

Metsec lightweight trusses, combined with SFS

stand-alone walling systems, are becoming ever

more popular for constructing complete

structures.

The Metsec Lattice Beam and Framing Divisions

work together closely to provide total construction

solutions for the developer.

The complete wall and roof solution is frequently

installed through the Metsec Framing Division’s

approved installer network. This adds to the

complete, one-source nature of the package in

keeping with the demands of the modern

construction industry.

Patching Lodge, Brighton

Metsec double curve roof system

Metsec lightweight trusses and Z-section purlins can

also be combined with stand alone, light gauge, cold

rolled Steel Framing Systems (SFS) to provide

complete one-source building solutions

15

16

16


Over-roof systems

Building services

Ring beams

Where existing flat roofs are starting to fail or

require upgrading, one option to consider is the

creation of a new pitched, or curved, over-roof

which can be constructed quickly and cost

effectively using lattice trusses.

The lightweight lattice over-roofing system avoids

the need to strengthen the existing roof structure

and can give an existing building a much needed

facelift - typically at a fraction of new build costs.

The new trusses can be spaced at much wider

centres than other over-roof systems, which results

in fewer penetrations and fixings into the existing

structure.

The new lattice trusses are installed to span across

St. Lukes School, Portsmouth.

the building and provide a range of benefits for

the building owner, including improved water

run-off and enhanced building insulation. The

additional space created under the new structure

can also be used to house building services

making usable space available elsewhere in the

structure.

The Metsec lattice team have gained considerable

expertise in the design of trusses for use in over-

roofing projects both large and small.

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17

17


Eaves cantilever systems

Top chord cantilever

This detail can be used for small

span cantilevers of up

to 1m.

Stiffener angles can be welded

to the sides of the top chord, if

required, to provide an

economic cantilever solution.

Cantilever bolted to welded

stub-post

This detail can be used for

medium span cantilevers of

up to 2m.

The cantilever arm is bolted

to the end post which is

supplied welded into the end

of the lattice.

Since the cantilever roof

element does not require an

insulation layer the line of

the supporting cantilever

eaves structure is

correspondingly raised to

support the top sheet.

17

18

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Loose, bolt-on cantilever

This detail can be used for large

span cantilevers of

over 2m.

The cantilever arm extends

into the building to provide an

adequate backing span and is

bolted on to the top chord of

the lattice.

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19

19

Ceilings and service supports

Ceilings and service support systems

Metsec parallel lattice beams are the ideal

solution for the support of ceiling structures

within existing buildings. Whether the ceiling is a

simple suspension from a secondary grid of

C-sections or is ‘walk-on’ and supported from the

bottom chord of the lattice beam, Metsec has a

range of solutions.

Lattice beams are ideal for clean rooms, data

halls, telecommunications facilities, retail units

and secure locations where long, unobstructed

spans are essential and where their light weight

can minimise the load on to the existing structure.

They can also allow the passage of services

through the lattice’s web without any loss of head

room or need for exposed pipework which can form

a potential dust trap.

Metsec lattice primary members together with

Z or C-section secondary members provide a cost

effective solution to ceiling/service support

requirements.

Metsec parallel beam

Used with secondary C-sections

to support a suspended ceiling.

In the illustration shown, the

ability to run split-level ducting

through the lattice without any

loss of internal headroom is

clearly demonstrated. A further

benefit is that future changes to

the building services can easily

be accommodated by running

piping or ducting through the

lattice.

Service support/pipebridge

Metsec provide an economic system to form

pipebridge and service supports.

Lightweight lattice joists are provided in pairs and

braced together to form spans of up to 40m.

The majority of pipebridges are supplied with a

galvanised finish for external applications.

However, various paint specifications are also

available where required.

Millennium Dome, London

Millennium Dome, London

19

20

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Walk-on ceiling systems Ceilings and service supports

Metsec parallel beam

supporting walk-on ceiling

Metsec parallel ceiling support

beams can be used for walk-on

ceiling applications.

Metsec lattice beams are frequently used to create

a support structure for walk-on ceilings in which

an interlocking system of steel faced planks is

used to create a load bearing ceiling construction.

These systems are particularly popular in the

creation of “clean rooms” where sealing the joints

of these planks creates a closed ceiling void in

which the high level mechanical and electrical

services can be installed without the need for

secondary floors or complex support systems.

Ceiling and service support structure

These systems provide an excellent solution to the

location of services and are specifically designed

to allow maintenance engineers to walk on top of

the ceiling system. This facilitates the easy access

to services and components without the need for

the access equipment normally associated with

more basic ceiling installations.

The two photographs to the left show projects

where Metsec lattice beams are employed in walk

on ceiling constructions.

Clean room ceiling support structure

20

Floor beams Floor beams

Traditional floor systems

Metsec lattice joists offer a simple solution for the

construction of both conventional and mezzanine

floors due to their excellent strength to weight ratio.

This means that a typical lattice joist can weigh up to 50%

less than their hot rolled counterparts.

Of great importance to the designer is the fact that the

internal space can be optimised by passing services through

the web of the lattice joists rather than having to suspend

them underneath causing a significant loss of headroom.

Similarly, the ability to insert flush fitting timber sections into

the top and bottom chords offers a simple medium for the

fastening of floor decking and/or plasterboard ceilings.

In addition to the direct reduction of the environmental

footprint of a construction project by virtue of their

lighter weight, lattice beams can also help to reduce the

environmental footprint of the project by using off-site

fabrication to speed up the construction process of the

floor as the lighter sections can generally be transported

and handled more efficiently on site.

White Rose Shopping Centre, Leeds.

Traditional floors

Metsec parallel floor joists at

600mm centres with the floor

decking nailed to the top chord

and two layers of plasterboard

to the bottom chord.

21

Floor beams Floor beams

Mezzanine floor systems

Mezzanine floors

Metsec parallel floor joists with

C-sections supporting floor decking.

The photograph below shows a

project where 17m span lattice joists

were designed to carry storage

loadings.

Zurich Insurance, Wiltshire

22

Fixing details Fixing details

Typical fixing details

F1 – Shoe fixing to concrete padstone F2 – Beam laid to fall

on sloping shoes

F3 – Full depth fixing to concrete padstone F4 – Full depth seating with beam extended

F5 – Beam fixing to internal wall F6 – Beam laid to fall with full depth seat

23


F7 – Fixing to concrete face with loose angle cleats F8 – Shoe fixing to hot rolled steelwork

F9 – Shoe fixing to hot rolled steelwork (pair) F10 – Full depth fixing to the web of hot rolled

steelwork

F11 – Full depth fixing to hot rolled steelwork F12 – Fixing to internal hot rolled steelwork

24


Typical fixing details

F13 – Beam to column flange fixing F14 – Beam to column fixing with plate welded

to column

F15 – Beam to beam trimmer fixing F16 – Typical bridging fixing detail

F17 – Bracing fixing detail Note

‘F’ and ‘T’ details illustrate a typical range of connections that are

available. Other connections can be fabricated to suit site conditions.

25


T1 – Full depth fixing with bearing plate T2 – Purlin to truss fixing

T3 – Truss to column flange fixing T4 – Standard shoe fixing to hot rolled steelwork

T5 – Beam to truss trimmer fixing

T6 – Standard shoe fixing to concrete padstone

26

Chord and bridging details Chord and bridging details

Chord details

Nominal dimensions

Chord

type

y

mm

Area

cm2

rxx

cm

ryy

cm

Ixx

cm4

Iyy

cm4

Zxx

cm3

Zyy

cm3

120

35 50 35

MB 50

2.5 y x x

23.27

5.16

1.97

3.14

19.96

50.90

7.47

8.48

135

37.5 60 37.5

MD 4 y

50 x x

24.25

8.53

1.93

3.66

31.84

114.12

12.36

16.91

155

40 75 40

MG 5 y

75 x x

38.13

13.89

2.84

4.27

112.13

253.58

29.41

32.72

210

65 80 65

MJ 5 y

100 x x

45.04

19.14

3.85

5.32

283.15

542.17

51.52

51.64

230

70 90 70

ML 6 y

100 x x

45.51

23.84

3.85

5.94

353.90

840.11

64.94

73.05

27

Chord and bridging details Chord and bridging details

Bridging details

Bridging

Bridging is recommended

during the construction period

to enable the beams to support

the construction loads, and to

hold the beams at the centres

and positions indicated on the

plans.

However, when construction

loads are deemed to be light,

bridging can be omitted at the

discretion of the Metsec Lattice

Beam Technical Department.

Bridging

Maximum spacing of bridging for chord sections (m)

Type MB MD MG MJ ML

3.8 4.4 5.2 6.4 7.5 7

Bridging consists of steel angles

connected to the top chord of

the lattice. Bridging may also be

required to the bottom chords

depending on design

considerations. The slenderness

ratio l/r of the bridging angle

must not exceed 250.

Sizes of bridging angle for various joists centres

Centres of joists (m) Standard bridging angle (mm)

0 – 2.4 50 x 50 x 3

2.4 – 3.0 60 x 60 x 5

3.0 – 3.9 80 x 80 x 6

3.9 – 4.9 100 x 100 x 8

Wind reversal

Where construction loads are

light the bottom chords should

be checked for compression due

to the wind reversal forces.

Please contact Metsec Lattice

Beam Technical Department for

further advice.

Knee bracing 28

Design examples and load tables Design examples and load tables

Design examples

Parallel beam - span/depth ratio

As a guide, depths of roof beam, conform approximately to

the following:

Approximate depth = span/20

i.e. 10m span/20 = 500mm deep

Design example

Joist span 10,000mm

Joist spacing 4,500mm

Roof loading:

Decking and insulation 0.20kN/m2

Ceiling and services 0.30kN/m2

Allow S.Wt steelwork 0.10kN/m2

Dead load 0.60kN/m2 x 1.4 = 0.84kN/m2

Imposed load 0.60kN/m2 x 1.6 = 0.96kN/m2

Total load 1.20kN/m2 1.80kN/m2

Total load requirement = 1.80 x 4.5 = 8.10kN/m

Imposed load requirements = 0.6 x 4.5 = 2.70kN/m

Refer to load tables.

Use Metsec lattice beams ref: MD50

Total load capacity 8.83kN/m (>8.10)

Imposed load capacity 3.83kN/m (>2.70)

Important

The lighter the beam, the more cost effective the solution.

Designation

The designation of beam configurations and depths is

given by a simple letter and number code, as follows:

Chord Depth at Configuration Pitch

type shallow end or radius

MB – ML (cm) T (tapered) Gradient (o)

TR (pitched) Radius (m)

PP (parallel pitched)

I (inverted)

CT (curved truss)

CB (curved beam)

Example 1

MD 50

Thus MD50 comprises MD type chord sections with an overall beam

depth of 500mm without pitch or taper.

Example 2

MJ 60 TRW 100

Thus MJ60TRW(100) comprises MJ type chord sections with an

overall truss depth at the shallow end of 600mm rising to a central

ridge with a Warren type web pattern and a 100 slope.

Stone Road, West Midlands

29


Typical truss options N – type truss

This is the most economical type of joist or truss when

considering gravity loading only and where stress

reversals are insignificant - i.e. longer diagonal members

are in tension.

Warren type truss

May be preferred in having a better appearance than the

N – type joist or truss. Diagonals are alternatively struts

and ties.

This results in a frame less susceptible to deflection than

the N – type.

Warren type truss with vertical posts

Additional members are introduced to the basic warren

type joist or truss to support loads which do not occur at

node positions.

Typical tapered truss options

Summerhill Primary School, West Midlands

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race

V

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race

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rtic

al b

race

V

ert

ica

l b

race

Lattice beam, in steel frame

construction

Lattice beam

The Metsec lattice beam can

provide a very attractive,

lightweight, economical

solution when used as a main

support to the roof structure,

being able to meet short,

medium or long span

requirements.

The beam can be provided with

fully fixed end connections

determined by simple frame

analysis if required.

Alternatively, they can be

simply supported to carry

vertical applied dead and

imposed loads and fixed for

horizontal wind as a common

design assumption.

Purlins

The most economic section used

for supporting the roof cladding

is a cold rolled purlin.

Metsec cold rolled Z-section

purlins provide adequate lateral

restraint to the top

(compression) chord of the

lattice beams.

Bracing

The longitudinal tensile forces

in the Metsec Z-section purlins

resulting from lateral restraint to

the lattice beams are

transmitted to the diagonal

rafter bracing system provided

at each end of the building. In

addition to providing stability to

the lattice beams, bracing also

resists wind loading at the gable

ends (i.e. gable posts propped at

bracing node points) and acts as

stability bracing during

erection.

For longer buildings additional

bracing may be required to

intermediate bays.

Vertical bracing as shown on the

roof plan ensures that all forces

are transmitted to the

foundations.

Gable posts

Optional

bottom tie

CL

Ridge

Knee brace

as required

Cleader rail

Metsec lattice

beam

Metsec lattice

beam

Metsec lattice

beam

Metsec Z purlins

Metsec lattice

beam

Metsec lattice

beam

Metsec lattice

beam

31


Load bearing walls

Ho

rizon

tal s

pa

n

of

rin

g b

eam

Lo

ng

itu

din

al t

ie

Lo

ng

itu

din

al t

ie

Lattice truss in load bearing wall

construction

Metsec

truss

Metsec

Z purlins

Metsec

truss

Services

Metsec truss

Metsec truss

“Suspended” ceiling

Eaves

bracing

Lattice truss

The Metsec lattice truss provides a

lightweight, economic solution

when used as the roof lid main

support member on load bearing

wall construction. The lattice form

provides a more flexible service

zone within the ceiling void.

Large spans of up to 40m are easily

accommodated.

Purlins

Metsec cold rolled Z-section

purlins are used as economic

support to the roof cladding and

provide adequate lateral restraint

to the top (compression) chord of

the lattice truss.

Rafter bracing

The longitudinal forces in the

Metsec Z-section purlins resulting

from lateral restraint to the lattice

truss are transmitted to the

diagonal rafter bracing system.

Bottom tie bracing

The wind loading on vertical

spanning side walls is resisted by a

horizontal bracing system utilising

a steel or concrete ring beam at

bottom chord (eaves) level. This

ring beam may be returned on the

gable ends to provide intermediate

lateral support to the walls.

The longitudinal ties also serve as

lateral restraint members to the

bottom chord of lattice truss in

compression from wind uplift.

Ring

beam

32


Load tables - Parallel beams

Joist Overall Typical node Ixx Self weight

type depth (mm) centres (mm) (cm4) (kg/m)

5

6

7

8

9

Span (m)

10

11

12

13

14

15

16

17

MB22 220 250 816 10 6.58 3.81 2.40 2.86 1.65 1.04

MB27 270 350 1328 10 6.42 5.35 3.90 2.61 4.01 2.69 1.69 1.13

MB30 300 380 1697 11 11.32 7.86 4.99 3.34 2.35 5.94 3.44 2.16 1.45 1.02

MD30 300 380 2762 16 13.33 11.11 8.11 5.44 3.82 2.78 8.33 5.59 3.52 2.36 1.66 1.21

MB35 350 600 2416 12 13.56 9.42 6.92 4.75 3.34 2.43 8.45 4.89 3.08 2.06 1.45 1.06 MD35 350 600 3941 17 17.08 14.24 11.58 7.76 5.45 3.97 2.98

10.68 7.98 5.03 3.37 2.36 1.72 1.29 MG35 350 600 5429 28 37.01 25.33 15.95 10.68 7.50 5.47 4.11 3.17 2.49 18.99 10.99 6.92 4.64 3.26 2.37 1.78 1.37 1.08

MB40 400 600 3263 12 15.79 10.97 8.06 6.17 4.51 3.29 2.47 9.87 6.61 4.16 2.79 1.96 1.43 1.07 MD40 400 600 5334 17 17.17 14.31 12.27 10.50 7.37 5.37 4.04 3.11 10.73 8.95 6.80 4.56 3.20 2.33 1.75 1.35 MG40 400 600 7504 28 40.28 30.87 22.04 14.77 10.37 7.56 5.68 4.38 3.44 2.76

25.17 15.19 9.57 6.41 4.50 3.28 2.47 1.90 1.49 1.20 MB45 450 600 4240 13 18.03 12.52 9.20 7.04 5.56 4.27 3.21 11.27 7.82 5.41 3.62 2.54 1.85 1.39 MD45 450 600 6940 20 22.15 18.46 15.82 12.42 9.59 6.99 5.25 4.05 3.18 2.55

13.85 11.54 8.85 5.93 4.16 3.04 2.28 1.76 1.38 1.11 MG45 450 600 9926 29 42.82 35.63 26.18 19.53 13.72 10.00 7.51 5.79 4.55 3.64 2.96 2.44 26.76 20.10 12.66 8.48 5.95 4.34 3.26 2.51 1.98 1.58 1.29 1.06

MJ45 450 600 12965 37 42.18 35.15 30.13 25.52 17.92 13.06 9.81 7.56 5.95 4.76 3.87 3.19 2.66 26.36 21.97 16.53 11.07 7.78 5.67 4.26 3.28 2.58 2.07 1.68 1.38 1.15 MB50 500 600 5345 14 20.26 14.07 10.34 7.91 6.25 5.06 4.05 3.12 2.45 12.66 8.79 6.46 4.57 3.21 2.34 1.76 1.35 1.06 MD50 500 600 8759 19 21.45 17.88 15.32 13.41 11.04 8.83 6.63 5.11 4.02 3.22 2.62

13.41 11.17 9.58 7.48 5.25 3.83 2.88 2.22 1.74 1.40 1.13 MG50 500 600 12696 29 44.82 37.35 29.68 22.72 17.55 12.79 9.61 7.40 5.82 4.66 3.79 3.12 2.60

28.01 23.34 16.19 10.84 7.62 5.55 4.17 3.21 2.53 2.02 1.65 1.36 1.13

MJ50 500 600 16649 37 44.31 36.93 31.65 27.70 23.01 16.78 12.60 9.71 7.64 6.11 4.97 4.10 3.41 27.70 23.08 19.78 14.22 9.99 7.28 5.47 4.21 3.31 2.65 2.16 1.78 1.48 ML50 500 600 20650 46 55.94 46.62 39.96 34.96 28.54 20.81 15.63 12.04 9.47 7.58 6.17 5.08 4.24

34.96 29.14 24.97 17.64 12.39 9.03 6.79 5.23 4.11 3.29 2.68 2.20 1.84 MB55 550 600 6580 14 20.38 15.62 11.48 8.79 6.94 5.62 4.65 3.84 3.02 2.42 12.74 9.76 7.17 5.49 3.95 2.88 2.16 1.67 1.31 1.05 MD55 550 600 10791 19 20.42 17.02 14.59 12.76 11.35 9.93 8.17 6.29 4.95 3.96 3.22 2.65

12.76 10.64 9.12 7.98 6.47 4.72 3.55 2.73 2.15 1.72 1.40 1.15 MG55 550 600 15813 30 46.39 38.66 33.14 25.41 20.07 15.93 11.97 9.22 7.25 5.81 4.72 3.89 3.24

29.00 24.16 20.16 13.51 9.49 6.92 5.20 4.00 3.15 2.52 2.05 1.69 1.41

MJ55 550 600 20812 38 45.99 38.33 32.85 28.75 25.55 20.97 15.76 12.14 9.54 7.64 6.21 5.12 4.27 28.75 23.95 20.53 17.78 12.49 9.10 6.84 5.27 4.14 3.32 2.70 2.22 1.85 ML55 550 600 25824 47 58.07 48.39 41.48 36.29 32.26 26.02 19.55 15.06 11.84 9.48 7.71 6.35 5.30

36.29 30.25 25.92 22.06 15.49 11.29 8.49 6.54 5.14 4.12 3.35 2.76 2.30 MB60 600 600 7943 13 19.15 15.96 12.62 9.66 7.63 6.18 5.11 4.29 3.64 2.92 11.97 9.97 7.88 6.04 4.77 3.47 2.61 2.01 1.58 1.27 MD60 600 600 13037 18 19.20 16.00 13.71 12.00 10.67 9.60 8.73 7.58 5.98 4.79 3.89 3.21 2.67

12.00 10.00 8.57 7.50 6.67 5.70 4.28 3.30 2.60 2.08 1.69 1.39 1.16 MG60 600 600 19277 28 47.65 39.71 34.03 28.09 22.19 17.98 14.59 11.24 8.84 7.08 5.76 4.74 3.95 29.78 24.82 21.27 16.47 11.56 8.43 6.33 4.88 3.84 3.07 2.50 2.06 1.72

MJ60 600 900 25453 36 41.17 34.31 29.41 25.73 22.87 20.59 18.71 14.84 11.67 9.35 7.60 6.26 5.22 25.73 21.44 18.38 16.08 14.30 11.13 8.36 6.44 5.07 4.06 3.30 2.72 2.27 ML60 600 900 31594 45 51.98 43.31 37.13 32.48 28.88 25.99 23.63 18.42 14.49 11.60 9.43 7.77 6.48 32.48 27.07 23.20 20.30 18.05 13.82 10.38 8.00 6.29 5.04 4.09 3.37 2.81 MB65 650 600 9436 15 26.96 18.72 13.76 10.53 8.32 6.74 5.57 4.68 3.99 3.44 2.82

16.85 11.70 8.60 6.58 5.20 4.13 3.10 2.39 1.88 1.50 1.22 MD65 650 600 15496 20 36.08 30.07 24.31 18.61 14.71 11.91 9.84 8.27 7.05 5.69 4.63 3.81 3.18

22.55 18.79 15.19 11.63 9.19 6.78 5.09 3.92 3.08 2.47 2.01 1.65 1.38 MG65 650 600 23088 29 48.66 40.55 34.76 30.41 24.31 19.69 16.27 13.46 10.59 8.48 6.89 5.68 4.74 30.41 25.34 21.72 19.01 13.85 10.10 7.59 5.84 4.60 3.68 2.99 2.47 2.06 MJ65 650 900 30572 37 42.38 35.31 30.27 26.49 23.54 21.19 19.26 17.66 14.02 11.23 9.13 7.52 6.27 26.49 22.07 18.92 16.55 14.71 13.24 10.05 7.74 6.09 4.87 3.96 3.26 2.72 ML65 650 900 37960 46 53.64 44.70 38.31 33.52 29.80 26.82 24.38 22.13 17.41 13.94 11.33 9.34 7.79

33.52 27.94 23.94 20.95 18.62 16.60 12.47 9.61 7.56 6.05 4.92 4.05 3.38 MB70 700 900 11057 16 29.20 20.27 14.90 11.40 9.01 7.30 6.03 5.07 4.32 3.72 3.24 2.72 18.25 12.67 9.31 7.13 5.63 4.56 3.63 2.80 2.20 1.76 1.43 1.18 MD70 700 900 18168 21 33.18 27.65 23.70 20.16 15.93 12.90 10.66 8.96 7.63 6.58 5.42 4.47 3.73

20.73 17.28 14.81 12.60 9.96 7.95 5.97 4.60 3.62 2.90 2.35 1.94 1.62 MG70 700 900 27247 29 43.44 36.20 31.03 27.15 24.13 21.41 17.69 14.87 12.50 10.01 8.13 6.70 5.59 27.15 22.62 19.39 16.97 15.08 11.92 8.95 6.90 5.42 4.34 3.53 2.91 2.43 MJ70 700 900 36171 37 43.24 36.04 30.89 27.03 24.02 21.62 19.66 18.02 16.59 13.28 10.80 8.90 7.42 27.03 22.52 19.31 16.89 15.02 13.51 11.88 9.15 7.20 5.76 4.69 3.86 3.22 ML70 700 900 44922 46 54.89 45.74 39.20 34.30 30.49 27.44 24.95 22.87 20.60 16.50 13.41 11.05 9.21 34.30 28.59 24.50 21.44 19.06 17.15 14.76 11.37 8.94 7.16 5.82 4.80 4.00 MD80 800 900 24153 22 34.59 28.83 24.71 21.62 18.37 14.88 12.30 10.34 8.81 7.59 6.61 5.81 4.95 21.62 18.02 15.44 13.51 11.48 9.30 7.69 6.11 4.81 3.85 3.13 2.58 2.15 MG80 800 900 36606 30 44.35 36.96 31.68 27.72 24.64 22.17 20.16 17.25 14.70 12.67 10.93 9.01 7.51 27.72 23.10 19.80 17.32 15.40 13.86 12.03 9.26 7.29 5.83 4.74 3.91 3.26 MJ80 800 900 48803 38 44.27 36.89 31.62 27.67 24.59 22.13 20.12 18.44 17.03 15.81 14.57 12.01 10.01 27.67 23.06 19.76 17.29 15.37 13.83 12.58 11.53 9.71 7.78 6.32 5.21 4.34 ML80 800 900 60635 47 56.53 47.11 40.38 35.33 31.41 28.27 25.70 23.55 21.74 20.19 18.10 14.92 12.44 35.33 29.44 25.24 22.08 19.63 17.67 16.06 14.72 12.07 9.66 7.86 6.47 5.40 MD90 900 900 30990 22 35.65 29.71 25.46 22.28 19.80 16.86 13.94 11.71 9.98 8.60 7.49 6.59 5.83 22.28 18.57 15.91 13.93 12.38 10.54 8.71 7.32 6.17 4.94 4.02 3.31 2.76 MG90 900 900 47355 31 44.57 37.14 31.83 27.85 24.76 22.28 20.26 18.57 16.73 14.42 12.57 11.04 9.71 27.85 23.21 19.90 17.41 15.47 13.93 12.66 11.61 9.43 7.55 6.14 5.06 4.22 MJ90 900 900 63349 39 44.57 37.14 31.84 27.86 24.76 22.29 20.26 18.57 17.14 15.92 14.86 13.93 12.99 27.86 23.21 19.90 17.41 15.48 13.93 12.66 11.61 10.71 9.95 8.21 6.76 5.64 ML90 900 900 78732 48 57.32 47.77 40.94 35.83 31.85 28.66 26.06 23.88 22.05 20.47 19.11 17.91 16.15 35.83 29.86 25.59 22.39 19.90 17.91 16.28 14.93 13.78 12.55 10.20 8.41 7.01 MG100 1000 900 59492 32 44.29 36.91 31.63 27.68 24.60 22.14 20.13 18.45 17.03 15.82 14.09 12.38 10.97 27.68 23.07 19.77 17.30 15.38 13.84 12.58 11.53 10.65 9.48 7.71 6.35 5.30 MJ100 1000 900 79809 40 44.35 36.96 31.68 27.72 24.64 22.18 20.16 18.48 17.06 15.84 14.78 13.86 13.04 27.72 23.10 19.80 17.32 15.40 13.86 12.60 11.55 10.66 9.90 9.24 8.52 7.10 ML100 1000 900 99214 49 57.50 47.92 41.07 35.94 31.94 28.75 26.14 23.96 22.12 20.54 19.17 17.97 16.91

35.94 29.95 25.67 22.46 19.97 17.97 16.34 14.97 13.82 12.83 11.98 10.59 8.83 Span (m) 5 6 7 8 9 10 11 12 13 14 15 16 17

Standard camber (mm) 3 4 6 7 9 12 14 16 19 22 26 29 33 33


Notes on load tables

1. All loads are in kilo Newtons per

metre (kN/m),calculated in accordance

with BS 5950-1 and 5:1998.

2. Figures in black type are ultimate total

loads per metre.

3. BS 5950: 1998 recommends that imposed

load deflections are limited to span/360

where applicable. Therefore safe working

loads shown in red type are calculated with

a deflection limit of span/360.

4. By calculating Unfactored imposed loads and

ultimate total loads in kilo Newtons per linear

metre (kN/m) and referring to the appropriate

table a suitable selection can be made by

satisfying both imposed load and total

load criteria.

5. Tables are based on:

5.1 The top (compression) chord of the beam

is provided with adequate lateral restraints at

spacings not greater than 1.8m.

5.2 The load is uniformly distributed on the

full span.

6. Roof beams are fabricated with an upward

camber. The approximate camber for various

spans is shown in the tables.

Floor joists are supplied straight unless a

camber is specifically requested.

7. When design requirements are for depths

greater than 2.0m, or when curved, pitched or

tapered profiles are required, please refer to

LatticeSPEC design software or consult the

Metsec Lattice Beam Technical Department.

18

19

20

21

22

23

24

25

Span (

26

)

27

28

29

30

31

32

33

34

No

1.

2.

3.

4.

5.

6.

7.

tes on load tables

All loads are in kilo Newtons per metre

(kN/m), and are calculated in accordance with

BS 5950-1: 2000 and 5: 1998.

Figures in black type are Ultimate total loads

per metre.

BS 5950-1: 2000 and 5: 1998 recommends that

Unfactored imposed load deflections are

limited to span/360 where applicable.

Therefore safe working loads shown in red

type are calculated with a deflection limit of

span/360.

By calculating Unfactored imposed loads and

Ultimate total loads in kilo Newtons per linear

metre (kN/m) and referring to the appropriate

table a suitable selection can be made by

satisfying both imposed load and total load

criteria.

Tables are based on:

5.1 The top (compression) chord of the beam is

provided with adequate lateral restraints at

spacings not greater than 1.8m.

5.2 The load is uniformly distributed on the

full span.

Roof beams are fabricated with an upward

camber. The approximate camber for various

spans is shown in the tables.

Floor joists are supplied straight unless a

camber is specifically requested.

When design requirements are for depths

greater than 2.0m, or when curved, pitched or

tapered profiles are required, please refer to

LatticeSPEC design software or consult the

Metsec Lattice Beam Technical Department.

2.24 0.97 2.88 1.25 3.57 3.03 2.60 1.55 1.32 1.13

2.73

1.19

3.60 3.06 2.62 1.56 1.33 1.14 4.46 3.79 3.25 2.81 1.94 1.65 1.41 1.22

3.33 2.83

1.45 1.23

4.40 3.74 3.21 2.77

1.91 1.62 1.39 1.20 5.46 4.64 3.98 3.44 2.99 2.37 2.01 1.73 1.49 1.30

2.68

1.16

3.99 3.39 2.91

1.73 1.47 1.26

5.28 4.49 3.85 3.33 2.89 2.53

2.29 1.95 1.67 1.44 1.26 1.10

6.56 5.58 4.78 4.13 3.59 3.14 2.77 2.85 2.42 2.08 1.79 1.56 1.36 1.20

3.14 2.67

1.36 1.16

4.71 4.00 3.43 2.96 2.58

2.04 1.74 1.49 1.29 1.12

6.25 5.31 4.56 3.94 3.42 3.00 2.64

2.71 2.31 1.98 1.71 1.49 1.30 1.14

7.76 6.60 5.66 4.89 4.25 3.72 3.27 2.90

3.37 2.86 2.46 2.12 1.85 1.61 1.42 1.26

4.17 3.55 3.04 2.63

1.81 1.54 1.32 1.14

6.32 5.38 4.61 3.98 3.46 3.03 2.67

2.75 2.33 2.00 1.73 1.50 1.32 1.16

8.43 7.17 6.15 5.31 4.62 4.04 3.56 3.15 2.80

3.66 3.11 2.67 2.30 2.00 1.75 1.54 1.37 1.21

10.48 8.91 7.64 6.60 5.74 5.02 4.42 3.91 3.48 3.10 2.78

4.55 3.87 3.31 2.86 2.49 2.18 1.92 1.70 1.51 1.35 1.21

5.20 4.55 3.90 3.37 2.93 2.57

2.32 1.98 1.69 1.46 1.27 1.11

8.18 6.96 5.96 5.15 4.48 3.92 3.45 3.05 2.71

3.55 3.02 2.59 2.24 1.94 1.70 1.50 1.33 1.18

10.95 9.31 7.98 6.89 5.99 5.25 4.62 4.09 3.63 3.24 2.91 2.62

4.75 4.04 3.46 2.99 2.60 2.28 2.00 1.77 1.58 1.41 1.26 1.14

13.60 11.57 9.92 8.57 7.45 6.52 5.74 5.08 4.51 4.03 3.61 3.25 2.94 2.66

5.90 5.02 4.30 3.72 3.23 2.83 2.49 2.20 1.96 1.75 1.57 1.41 1.28 1.16

9.79 8.74 7.49 6.47 5.63 4.93 4.34 3.84 3.41 3.05 2.73

4.46 3.79 3.25 2.81 2.44 2.14 1.88 1.67 1.48 1.32 1.19

12.32 11.67 10.05 8.68 7.55 6.61 5.82 5.15 4.58 4.09 3.66 3.30 2.98

5.98 5.09 4.36 3.77 3.28 2.87 2.52 2.23 1.99 1.77 1.59 1.43 1.29

15.97 14.57 12.50 10.79 9.39 8.22 7.23 6.40 5.69 5.08 4.55 4.10 3.70 3.36 3.05 2.78 2.54

7.44 6.33 5.42 4.69 4.07 3.57 3.14 2.78 2.47 2.20 1.98 1.78 1.61 1.46 1.32 1.21 1.10

18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34

37 41 45 50 55 60 65 71 77 83 89 96 100 109 116 124 131

m

34


Load tables - Parallel beams

Joist Overall Typical node Ixx Self weight

type depth (mm) centres (mm) (cm4) (kg/m)

10

12

14

16

18

20

22

24

26

28

30

32

34

MG110 1100 900 73019 32 21.81 18.18 15.58 13.63 10.84 8.78 6.91 5.32 13.63 11.36 9.74 7.80 5.48 3.99 3.00 2.31

MJ110 1100 900 98184 40 21.87 18.22 15.62 13.67 12.15 10.93 9.29 7.16 5.63 4.51 3.66 13.67 11.39 9.76 8.54 7.36 5.37 4.03 3.11 2.44 1.96 1.59

ML110 1100 900 122080 50 28.61 23.85 20.44 17.88 15.90 14.31 11.55 8.90 7.00 5.60 4.56 3.75 3.13

17.88 14.90 12.77 11.18 9.15 6.67 5.01 3.86 3.04 2.43 1.98 1.63 1.36

MG120 1200 1200 87935 31 19.76 16.47 14.11 12.35 10.98 9.64 7.97 6.41 5.04 12.35 10.29 8.82 7.72 6.59 4.81 3.61 2.78 2.19

MJ120 1200 1200 118472 39 19.70 16.42 14.07 12.32 10.95 9.85 8.96 8.21 6.79 5.44 4.42 12.32 10.26 8.80 7.70 6.84 6.16 4.87 3.75 2.95 2.36 1.92

ML120 1200 1200 147330 48 26.38 21.98 18.84 16.49 14.66 13.19 11.99 10.74 8.45 6.76 5.50 4.53 3.78

16.49 13.74 11.78 10.30 9.16 8.05 6.05 4.66 3.67 2.94 2.39 1.97 1.64

MJ130 1300 1200 140675 40 19.42 16.18 13.87 12.14 10.79 9.71 8.83 8.09 7.47 6.46 5.25 12.14 10.11 8.67 7.58 6.74 6.07 5.52 4.45 3.50 2.80 2.28

ML130 1300 1200 174965 49 26.16 21.80 18.69 16.35 14.53 13.08 11.89 10.90 10.03 8.03 6.53 5.38 4.49

16.35 13.62 11.68 10.22 9.08 8.17 7.19 5.54 4.35 3.49 2.83 2.34 1.95

MJ140 1400 1200 164792 40 18.91 15.76 13.51 11.82 10.51 9.46 8.60 7.88 7.27 6.76 6.15 5.07 11.82 9.85 8.44 7.39 6.57 5.91 5.37 4.93 4.10 3.28 2.67 2.20

ML140 1400 1200 204984 50 25.80 21.50 18.43 16.13 14.33 12.90 11.73 10.75 9.92 9.21 7.65 6.30 5.26

16.13 13.44 11.52 10.08 8.96 8.06 7.33 6.48 5.10 4.08 3.32 2.74 2.28

MJ150 1500 1200 190823 41 18.32 15.27 13.09 11.45 10.18 9.16 8.33 7.63 7.05 6.54 6.11 5.73 11.45 9.54 8.18 7.16 6.36 5.73 5.21 4.77 4.40 3.80 3.09 2.55

ML150 1500 1200 237388 51 25.33 21.11 18.09 15.83 14.07 12.67 11.51 10.55 9.74 9.05 8.44 7.30 6.09

15.83 13.19 11.31 9.89 8.80 7.92 7.20 6.60 5.91 4.73 3.85 3.17 2.64

MJ160 1600 1200 218769 42 17.67 14.72 12.62 11.04 9.82 8.83 8.03 7.36 6.80 6.31 5.89 5.52 5.20

11.04 9.20 7.89 6.90 6.14 5.52 5.02 4.60 4.25 3.94 3.54 2.92 2.43

ML160 1600 1200 272176 51 24.77 20.64 17.69 15.48 13.76 12.38 11.26 10.32 9.53 8.85 8.26 7.74 6.98

15.48 12.90 11.06 9.67 8.60 7.74 7.04 6.45 5.95 5.42 4.41 3.63 3.03

MJ170 1700 1200 248628 42 16.97 14.14 12.12 10.61 9.43 8.48 7.71 7.07 6.53 6.06 5.66 5.30 4.99

10.61 8.84 7.58 6.63 5.89 5.30 4.82 4.42 4.08 3.79 3.54 3.31 2.77

ML170 1700 1200 309348 52 24.13 20.11 17.24 15.08 13.41 12.07 10.97 10.05 9.28 8.62 8.04 7.54 7.10

15.08 12.57 10.77 9.43 8.38 7.54 6.86 6.28 5.80 5.39 5.01 4.13 3.44

MJ180 1800 1200 280402 43 16.24 13.54 11.60 10.15 9.02 8.12 7.38 6.77 6.25 5.80 5.41 5.08 4.78

10.15 8.46 7.25 6.35 5.64 5.08 4.61 4.23 3.90 3.63 3.38 3.17 2.99

ML180 1800 1200 348905 53 23.43 19.53 16.74 14.65 13.02 11.72 10.65 9.76 9.01 8.37 7.81 7.32 6.89

14.65 12.21 10.46 9.15 8.14 7.32 6.66 6.10 5.63 5.23 4.88 4.58 3.88

MJ190 1900 1200 314089 44 15.51 12.92 11.08 9.69 8.62 7.75 7.05 6.46 5.96 5.54 5.17 4.85 4.56 9.69 8.08 6.92 6.06 5.38 4.85 4.41 4.04 3.73 3.46 3.23 3.03 2.85

ML190 1900 1200 390846 54 22.69 18.91 16.21 14.18 12.61 11.35 10.32 9.46 8.73 8.11 7.56 7.09 6.67

14.18 11.82 10.13 8.87 7.88 7.09 6.45 5.91 5.46 5.07 4.73 4.43 4.17

MJ200 2000 1200 349691 44 14.77 12.31 10.55 9.23 8.21 7.39 6.71 6.15 5.68 5.28 4.92 4.62 4.34

9.23 7.69 6.59 5.77 5.13 4.62 4.20 3.85 3.55 3.30 3.08 2.89 2.72

ML200 2000 1200 435172 55 21.92 18.27 15.66 13.70 12.18 10.96 9.96 9.13 8.43 7.83 7.31 6.85 6.45

13.70 11.42 9.79 8.56 7.61 6.85 6.23 5.71 5.27 4.89 4.57 4.28 4.03

Span (m) 10 12 14 16 18 20 22 24 26 28 30 32 34 Standard camber (mm) 12 16 22 29 37 45 55 65 77 89 100 116 131

Notes on load tables

1. All loads are in kilo Newtons per metre (kN/m),

and are calculated in accordance with BS 5950-1: 2000

and 5: 1998.

2. Figures in black type are Ultimate total loads

per metre.

3. BS 5950-1: 2000 and 5: 1998 recommends that

Unfactored imposed load deflections are limited to

span/360 where applicable. Therefore safe working

loads shown in red type are calculated with a deflection

limit of span/360.

4. By calculating Unfactored imposed loads and Ultimate

total loads in kilo Newtons per linear metre (kN/m) and

referring to the appropriate table a suitable selection

can be made by satisfying both imposed load and total

load criteria.

5. Tables are based on:

5.1 The top (compression) chord of the beam is

provided with adequate lateral restraints at spacings

not greater than 1.8m.

5.2 The load is uniformly distributed on the full span.

6. Roof beams are fabricated with an upward camber.

The approximate camber for various spans is shown in

the tables.

Floor joists are supplied straight unless a camber is

specifically requested.

7. When design requirements are for depths greater

than 2.0m, or when curved, pitched or tapered

profiles are required, please refer to LatticeSPEC

design software or consult the Metsec Lattice Beam

Technical Department.

35

Services and design software Services and design software

Services and general notes

Detailing service

Working from Architects’ and Consulting

Engineers’ drawings, Metsec’s team of engineers

and specialist 3D detailers will produce structural

layouts and sections to assist the site team along

with full fabrication drawings.

Customer service

Metsec are committed to providing the highest

levels of customer satisfaction and ensure that our

staff are trained to the highest possible levels in

order to assist our customers at all stages of the

design and installation process.

Our sales teams in particular have a thorough

knowledge of our products and should be able to

resolve most of your questions quickly and

professionally.

Research and development

Metsec operate a policy of continuous research

and development reserving the rights to change

the specification for products in this literature

without prior notice.

Company Registration

Metsec Lattice Beams Ltd

Registered Office: Units 10 & 11 Rolls

Royce Estate, Spring Road, Ettingshall,

Wolverhampton, West Midlands WV4 6JX.

Company Number: 07959668 (England)

Tividale High School, West Midlands.

36

Services and design software Services and design software

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Software

Design software

Metsec are pioneers when it comes to the

provision of design software packages. Our first

package for lattice design was produced in 1989,

since when we have been continually updating

and improving the packages that we offer.

Today, Metsec produce a number of stand-alone

design software packages including LatticeSPEC

for our complete range of lattice beam solutions.

This package enables the quick and easy design

of all types of lattice beams. It also includes an

option to export the profile of the lattice with its

end section in .dxf format, enabling specifiers to

import direct to their working drawings and to

quickly and efficiently complete their detailing.

For a free copy of the latest LatticeSPEC software

please contact MLB on 01902 408011or visit our

website: www.metseclatticebeams.com

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Designed and produced by Communication Design Partnership 01959 562777

37

http://www.metseclatticebeams.com/

Metsec Lattice Beams Ltd

Units 10 & 11 Rolls Royce Estate, Spring Road,

Ettingshall, Wolverhampton,

West Midlands. WV4 6JX

Tel: 44+ (0) 1902 408011

Email : [email protected]

www.metseclatticebeams.com

© Copyright METSEC plc 2008

In the interests of a policy of continuous research and development,

Metsec Lattice Beams Ltd reserve the right to change the

specifications in this publication without prior notice.

mailto:[email protected]

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