Exterior Insulation and the Cascadia Clip · 2017-06-22 · Cascadia Windows Ltd. 40107438...

Exterior Insulation and the Cascadia Clip

Presenter: Maddy Parrott

Manufacturer of fiberglass construction products

• Fiberglass windows

• Fiberglass doors

• Fiberglass cladding support systems

• Manufacturing plant located inLangley, BC

• In operation since 2008

• Current client base:

• BC, Alberta, Yukon, NWT,Washington, Oregon, Alaska

• Expanding to:

• Saskatchewan, Manitoba, Ontario,

• California, other central US States

Introduction

Agenda• Conservation – why does energy conservation in buildings matter?

• Building science and the building envelope: • Heat flow, U- & R- values, and thermal bridging

• Energy standards and code requirements

• Insulation• Types, considerations, and performances

• The Cascadia Clip• What it is and how we came up with it

• Where it’s been used

• What makes Cascadia stand out?

Cascadia Windows Ltd.40107438

Effective Thermal Performance of the Building Enclosure - Exterior WallsCourse Number 7

Michael Bousfield & Maddy Parrott

June 2017

Credit(s) earned on completion of this course will be reported to AIA CES for AIA members. Certificates of Completion for both AIA members and non-AIA members are available upon request.

This course is registered with AIA CES

for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner ofhandling, using, distributing, or dealing in any material or product._______________________________________

____

Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

This presentation is protected by US and International Copyright laws. Reproduction, distribution, display and use of the presentation without written

permission of the speaker is prohibited.

© Cascadia Windows Ltd. 2017

Copyright Materials

Many of today’s conventionally insulated wall assemblies fall short of even basic energy code compliance, let alone high performance. Learn what the code–prescribed targets are for your region, and what fiberglass cladding support technology can do solve this issue, while saving cost at the same time.

CourseDescription

LearningObjectives

1) Understand what building types are subject to the ASHRAE 90.1 Thermal Performance standard, and which compliance paths available for the ASHRAE 90.1 standard.

2) Understand the non-linear effect that highly conductive wall components have on the total effective wall R-value.

3) Understand how current conventional wall assemblies compare from a thermal point of view. Identify aspects of exterior wall detailing to target for thermal improvements.

4) Become aware of several conventional and state-of-the-art proprietary approaches that have been used in the past year to solve these issues and reduce costs.

At the end of the this course, participants will be able to:

Conservation, and the importance of it.

• Buildings account for 40% of total energy use in Canada and the US

• Buildings account for up to 30% of emissions

Now, more than ever, we must focus on conservation in our buildings

The environment is in danger

• Climate change is a real and pressing problem

• Policies and funding in place to protect the environment are getting cut

• Paris Agreement• Climate Action Plan• Waters of the U.S.

• Promoting environmentally dangerous energy sources

• Emphasis on fracking• Reviving coal

• We must individually strive to do better – on the demand side

The importance of building science in building envelopes

• Heat flow through a solid material

• Heat flow through solid materials in contact with one another

• Heat flow through a fluid material via loops

• Air is a fluid

• Stopped by filling air cavities

• Heat flow by waves, does not require a material to move through

• Blocked by opaque elements

Heat Flow

Heat flow – conduction

Conduction Conductivity Conductance (U-value)

• Heat flow through solid objects

• Rate of conductive heat flow

• Depends on material

• Conductivity/thickness

• Thermal properties of specific materials

• The lower the U-value, the more thermally effective the materialAluminum ~160 W/mK

Steel ~60 W/mKStainless Steel ~14 W/mKFiberglass – 0.15 to 0.30 W/mKWood ~0.10 to 0.15 W/mKInsulation Materials 0.022 to 0.080 W/mK

Heat flow – U-value and R-value

U-value: conductance

• How well heat moves through an assembly or material

• The lower the U-value, the better the assembly

• Efficiency and area-weighted averages require U-values

R-value: resistance

• How well a material or assembly resists heat flow

• NOMINAL: just the insulation R-value

• EFFECTIVE: includes all other materials

• Additive, but that’s it

1

𝑈= 𝑅

1

𝑅= 𝑈

Heat flow – insulation

Heat loss through building envelopes is controlled by insulation:

• Convection: filling air cavities to prevent convective loops

• Radiation: opaque material to block sitelines

• Conduction: insulation is a low-conductivity material

Insulation is key for minimizing heat loss through the building envelope

NOMINAL R-value

Resistances (additive)

Interior air film: 0.68

Interior gypsum: 0.45

Batt insulation: 12

Exterior plywood: 0.62

Exterior air film: 0.17

Total R-value: 13.92

Total U-value = 1/13.92

= 0.0718

Thermal performance

Heat flow – thermal bridging

Instead of moving through the efficient insulation, heat takes the path of least resistance: through the highest conductivity materials in an assembly

• Reduces the overall performance of the building envelope

• Occurs through the insulation

• Occurs when insulation is out of plane (basement to wall, etc.)

Results in much greater heat loss in envelopes

EFFECTIVE R-value

Through studs:Conductivity (k) of 3.5” of douglas fir:k = 0.7626 BTU-in/hr-ft2-F Ustuds = 0.7626/3.5 = 0.2179R = 1/0.2179 = 4.59 (just studs)

Through insulation: same as previous example (U-0.0718, R-13.92)

Total R = 0.17 + 0.62 + 4.59 + 0.45 + 0.68

= 6.51 (through studs)Total Uwallthroughstuds = 1/6.51 = 0.1536

Effect of thermal bridging on thermal performance

Effect of thermal bridging on thermal performanceWith studs at 16” o.c., wall is approx. 12% studs and 88% insulation

Utotal = (0.12)(0.1536)Total U-value = 0.0816Total R-value = 1/0.0816

= 12.25Nominal was R-14

+ (0.88)(0.0718)

= 0.0816

R-13.92 R-12.25• Insulation only 88%

effective


R-3.1

R-13.92 R-6.6• Insulation only 48%

effective

• Steel studs are even worse

• The higher conductivity the penetrating material, the worse the effectiveness


R-3.1

Energy Codes and Adoption

Commercial Energy Codes in the US and Canada

Individual building codes require improved energy performance by referencing various energy standards

In the US• Majority of states have building

codes which derive from the International Building Code

• The International Energy Conservation Code works in conjunction with the IBC

• The IECC is a mix of direct references to ASHRAE 90.1, or requirements built in which are mostly similar to ASHRAE 90.1 (almost identical for envelope requirements)

In Canada

• National Building Code is adopted and modified provincially

• Each province can choose to add energy requirements or not

• Two options in Canada, for the most part: the National Energy Code of Canada for Buildings, or ASHRAE 90.1 (the most common US energy standard)

What is ASHRAE 90.1?

An energy standard with three ways to achieve compliance:

• Prescriptive path*

• Building enclosure trade-off

• Energy cost budget path

*IECC has its own prescriptive path

ASHRAE 90.1 and “continuous insulation”

ASHRAE 90.1 stipulates that wall R-values must consider the effect of thermal bridging, to be representative of actual thermal performance

(i.e. consider effects of steel studs, girts, clips, slab-edges, balconies, eyebrows etc.).

Continuous Insulation (CI):

insulation that is continuous across all structural members without thermal bridges other than fasteners and service openings.

ASHRAE 90.1 Climate Zone 5

ASHRAE 90.1 Thermal Requirements

Continuous insulation

• Requires 100% continuous insulation

• Penetrated only by fasteners and service openings

• Does not include final performance target for whole assembly

• Screws through insulation

• EIFS

• Continuous metal girts

• Metal clips

• Fiberglass or composite clips

Ways of attaching cladding

ASHRAE 90.1 Thermal Requirements

Maximum assembly U-value

• Specified based on total wall assembly

• Based on actual performance of system

• Can use any materials in any configuration, as long as performance is met

• Screws through insulation

• EIFS

• Continuous metal girts

• Metal clips

• Fiberglass or composite clips

Ways of attaching cladding

Climate Zone 5 Example

R 15.6

ASHRAE 90.1 above-ground wall requirements

Construction Type Climate Zone

Type of

BuildingType of wall 1 2 3 4 5 6 7 8

Non-residential

Steel-framed

0.124

(R-8.1)

0.084

(R-11.9)

0.064

(R-15.6)

Residential0.124

(R-8.1)

0.064

(R-15.6)

0.042

(R-23.8)

0.037

(R-27)

Non-residential

Concrete

0.580

(R-1.72)

0.151

(R-6.62)

0.123

(R-8.13)

0.104

(R-9.62)

0.090

(R-11.1)

0.080

(R-12.5)

0.071

(R-14.1)

Residential0.151

(R-6.62)

0.123

(R-8.13)

0.104

(R-9.62)

0.090

(R-11.1)

0.080

(R-12.5)

0.071

(R-14.1)

0.052

(R-19.2)

Non-residentialWood-

framed

0.089

(R-11.2)

0.064

(R-15.6)

0.051

(R-19.6)

0.036

(R-27.8)

Residential0.089

(R-11.2)

0.064

(R-15.6)

0.051

(R-19.6)

0.036

(R-27.8)

InsulationOptions, performances, and considerations

Fiberglass Batts

• R-3.5 – 4/inch

• Combustible

• Permeable to liquid water and water vapour (indoor only)

Mineral Wool

• R-3.8 - 4.2/inch (stable)

• Non-combustible

• Permeable to liquid water and water vapour (outdoor ok)

Rigid Insulation

XPS EPS Polyisocyanurate

• R-5/inch (stable)

• Combustible

• Impermeable to liquid water and water vapour (outdoor ok)

• R-4/inch (stable)

• Combustible

• Moderately permeable to liquid water and water vapour (outdoor ok)

• R-5/inch (temperature variable)

• Combustible

• Permeable to liquid water and water vapour (indoor/membraned)

SprayfoamOpen cell (half pound) Closed cell (two pound)

• R-3.5 – 4/inch (stable)

• Combustible

• Permeable to water vapour and mostly permeable to liquid water (indoor)

• Susceptible to UV degradation

• R-5–6/inch (temperature variable)

• Combustible

• Impermeable to water vapour and liquid water (outdoor ok)

• Susceptible to UV degradation

Insulation Comparisons

Insulation R-value Non-combustible Moisture Tolerance Vapour Permeance

Fiberglass 3.5 – 4 NO Moderate High

Mineral Wool 4.2 YES High High

XPS 5 NO High Low

EPS 4 NO Moderate Low-Mid

Polyiso 5.5 – 6.2 NO Low-Moderate Low

Open cell sprayfoam 3.5 – 4 NO Moderate High

Closed cell sprayfoam 5 – 6 NO High Low

Insulation – challenges for higher performing walls

• Insulation is critical to the performance of your building, and it’s hard and cumbersome to replace- you want to do it once.

• Many different factors to weigh:• Minimize wall thickness

• Meet or exceed code minimums

• Minimize costs

• Create safe and effective walls.

• You want a system that has all aspects covered

Insulation – Interior

Interior Insulation• Thinner overall wall

• Generally poor – ok thermal performance

• Exterior sheathing is outdoor temperature, at risk for condensation

• Generally less expensive, but if only interior insulation is used

• Can reduce usable interior space

• Requires vapour barrier be inside building envelope

Insulation – Exterior

Exterior Insulation• Thicker overall wall, but can help

reduce stud size (6”4”)

• Best thermal performance (if done correctly)

• Keeps exterior sheathing at indoor temperature, eliminating condensation risk

• Extra layer of protection for the building materials from elements

• Allows for exterior placement of air/vapour barrier – best place for both hot and cold climates

Insulation – Exterior vs. Interior

Interior Insulation• Thinner overall wall

• Cheapest if only using interior insulation**

Exterior Insulation• Best thermal performance

• Best use of interior space

• Cheapest option to meet thermal requirements

• Best location for vapour barrier

• Best condensation resistance

Insulation – what about both?

Split insulation theoretically allows for the best of both worlds

Must ensure it is being designed properly

• Cannot have two vapour barriers• Two on either side means no drying

• Some insulations are vapour barriers

• Thermal bridging still a concern

Split Insulation – condensation

We’re going to run through some math:

• Assume: 100ft2 of wall area

• Assume conditions: • Interior temp 70F (21C)

• Interior RH 50%

• Exterior temp 20F (-6C)

• Use the equation:

Dew point temperature = 51F

𝑄 =𝐴 ∗ ∆𝑇

𝑅𝑣𝑎𝑙𝑢𝑒

Heat moving through wall, does not change no matter what part of the wall you look at

Can be manipulated to determine temperature at various locations or what R-value given temperatures will occur at

Split Insulation – 1” exterior mineral wool (R-4.2)

• R-12.6 effective

• Dew point temp located at R-4.8 from interior

• Interior sheathing temperature: 39F

• Risk of condensing on back of exterior gypsum





• Risk of condensing on back of exterior gypsum




• Interior sheathing temperature: 51.5F

• Back of exterior gypsum probably ok• Days colder than 20F could cause issues

• Generally pretty sensitive, only 0.5F buffer

Split Insulation – 4” exterior mineral wool (R- 16.8)




• Exterior gypsum likely not at risk of condensing

You’re at an R-25 wall to get the dew point in the right place.

4” exterior mineral wool (R-16.8) only


• Dew point temp located in the exterior insulation

• Interior sheathing temperature: close to interior temperature, 71F

• Back of exterior gypsum not at risk of condensing

You’ve met thermal requirements of all but zone 7 and 8 residential

Important things to remember:

Attachment matters• All examples assumed perfect

continuous insulation

• Needed R-15+ exterior insulation to be comfortable

• The worse your cladding attachment system, the less effective your exterior insulation is (R-16 with some systems might only be R-10 effective)

Weather is important

• Effect is pronounced with a bigger exterior/interior temperature difference

• Location of vapour barrier for summer vs. winter months

Insulation – real life applications for steel studs

• R-14.7 nominal (3.5” mineral wool)

• R-5.5 effective


• Bypass thick structural stud

• Attach cladding with thinner gauge continuous vertical girts


• R-7.4 effective


• Bypass thick structural studs

• Attach cladding with horizontal girts


• R-7.8 effective


• Intermittent metal clips

• Continuous metal rail




• Horizontal girts first, with insulation

• Vertical girts second, with insulation

• Theory is thermal bridging mitigated for half the insulation

• R-16.8 nominal (4” mineral wool)



• Same as last application

• Add plastic shim between metal girt layers

• R-16.8 nominal (4” mineral wool)


The Original Thermal SpacerWhere did the clip even come from?

Step 1

• OK, so we have a conductivity problem…

Backup wall

Problem: pull out

strength

Fiberglass

Z-girt

Insulation

• Let’s use a material with very low conductivity – like fiberglass.

Step 2

Main problem: Combustibility

Backup wall

Use long screw to attach

outer steel directly to stud

Backup wall

Problem: rotation at

inner leg

Problem:

web/screw

interference

Step 3

Problem: still a continuous member too expensive and poor thermal performance

Make pieces intermittent

Backup wall

Section

Problem: installation

is inconvenient, too

many pieces

Problem:

weak

furring

shape,

does not

provide

drainage

cavity

Step 4

If we use a Z-girt

instead… Is it done?

Backup wall

This concludes The American Institute of Architects Continuing Education Systems Course

©2016 BPDL The material contained in this course was

researched, assembled, and produced by BPDL and

remains its property. Questions or concerns about the

content of this course should be directed to the program

instructor.

The Cascadia Clip

• Essentially a “thermal washer”• Universal solution: appropriate for

almost any type of cladding (up to around 30psf)

• Approved for non-combustible construction virtually everywhere in North America

• Can supply just the clips, or the whole system (clips, screws and girts)

• Engineered for over 75,000 combinations of wall assemblies: The Cascadia Clip Calculator

Cascadia Clip Calculator

Got it! Demonstration worked as planned

Something’s up: do this demonstration manually

http://www.cascadiawindows.com/tools/cascadia-clip-calculator

http://www.cascadiawindows.com/tools/cascadia-clip-calculator

Cascadia Clip Calculator: Inputs

• Options for steel, concrete, and wood

• Steel options only allow for 4” steel studs because only the gauge matters for structural considerations

• Cascadia most often recommends no to batts in the cavity for steel framed, but it is an option

• Wood pre-selects to “yes”


• R-4.2/inch is mineral wool; R-6.2/inch is sprayfoam

• Rigid insulation can be used, we have details, it’s just generally more labour

• Stainless steel screws provide better thermal performance

• Using only one screw allows for best thermal performance in strict wall thickness situations


• Horizontal spacing goes along with studs

• With light cladding and low wind loads, possible skip studs

• For concrete backups start at 24”, usually

• Calculator goes up to 20psf, which covers most claddings

• Have done projects up to 28psf, just get in contact with us to help with the spacing

Cascadia Clip Calculator: Example

Cascadia Clip Calculator: Outputs

• Table and graphs show the same thing• Thermal results are full-wall effective R-values• Structural results have a FOS of 3.0 built in

Cascadia Clip Calculator: Optimizing

Find the smallest clip at the largest spacing to minimize # of clips used

Example: Project requires an R-15.6 wall, and the cladding must resist 60psf of suction pressure on the cladding.

Cascadia Clip Calculator: Easy Submittals

• Print results, and accompanied by engineering letters that validate the results, can be used as submittal documents

• Engineering letters located as links on the calculator page

Cascadia Clip projectsHigh-profile and interesting projects across the US

State University of New York- Medical School

• 8 stories

• 540,000SF

• 2” blue & 4” red clips

• Horizontal type

• Largest building constructed in Buffalo in decades

• Designed by HOK

Bullitt Center

• 6 stories• 52,000SF• 3.5” orange clips• Horizontal type• First Living Building Challenge

certified commercial buidingin North America

• Designed by Miller Hull Partnership

Zurich North America Headquarters

• 11 stories

• 735,000SF

• 3” purple clips

• Horizontal type

• LEED Platinum Certified

• Clips only used on soffit (middle building)

• Designed by Clayco

Portland University- Collaborative Life Sciences Building

• 12 stories

• 650,000SF

• 3.5” orange clips

• Vertical type

• LEED Platinum

• Designed by SERA Architects and CO Architects

MIT- Nanoscale Research Building

• 4 stories

• 200,000SF

• 3.5” orange clips

• Horizontal type

• Two floors of high-performance cleanrooms

• Designed by Wilson Architects

Denver Botanic Gardens Science Pyramid

• Pyramid structure

• 5,300SF

• 4” red and 5” yellow clips

• Vertical type

• Highly unique sloped roof/wall construction

• Designed by BURKETTDESIGN

Phoenix Airport- Terminal 3 Modernization

• 3 stories• 676,000SF• 3.5” orange clips• Vertical type• New high-performing terminal in

three phases to replace outdated existing terminal

• Designed by DWL Architects, Corgan, and Smithgroup JJR

Menil Drawing Institute

• 1 story

• 30,000SF

• 4” red clips

• Horizontal type

• First exhibition space of its kind

• Designed by Johnston Marklee

Why Cascadia Clip?

Cascadia Clip• Adjustability happens entirely

outboard of the insulation

• Cladding attachment is a Z or a hat, both incredibly strong shapes

• Cascadia Clip matches insulation, thermal break for entire depth of insulation

• Cascadia clip maintains thermal performance even at very tight spacing

Metal Clip & Rail Systems• Adjustable rails penetrate

insulation

• L-angle cladding attachment not very strong (much more likely to deflect)

• Thermal break is only a small portion of insulation depth

• Thermal performance relies on large spacing of clips: not always possible with various claddings

Why Cascadia Clip?

Insulation

Cascadia Clip

• Screws are directly fastened through the entire clip:

• Screws reduce thermal performance slightly (allowably)

• Screws allow for non-combustible construction

• Strength comes from screws, thick fiberglass allows for shear support – up to 30psf cladding

Composite Systems

• Best thermal performance

• Combustible structural connection

• Generally lower strength than metal

• Thinner webs mean lower strength

• Pull-out may be an issue

Fiberglass

Z-girt ?

Cascadia Clip: Adjustability

• Recently added adjustability options to deal with uneven substrates

• Vertical version: clip-specific adjustable brackets

• Horizontal version: clip-specific adjustable shims

Code Compliance: IAPMO-UES Report

• Third party certification of the Cascadia Clip

• Approves clip for use in IBC Types I, II, III, IV, and V construction

• ICC-ES equivalent

• Looks at several different aspects of design

• Only clip system with a nationally recognized third party code compliance report

Questions?

Exterior Insulation and the Cascadia Clip · 2017-06-22 · Cascadia Windows Ltd. 40107438...

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Transcript of Exterior Insulation and the Cascadia Clip · 2017-06-22 · Cascadia Windows Ltd. 40107438...