Re-roofing a Metal Building

Pre-engineered Metal Buildings have been in use for decades. Most of these buildings are still structurally sound but due to inferior paint systems often used in the past the roof might be experiencing leak problems resulting from rust, thermal expansion slotting fastener holes, or hurricane winds damaging the panels at fastener locations. The answer has always been coating the roof which is a short lived patch or biting the bullet and removing old panels and installing new ones. Removing the old roof panels leaves the customer susceptible to water damage during the removal/installation process. Also, quite often additional purlins have to be added to the existing roof to allow compliance with new building codes.

Architectural Metal Systems has two different solutions to this situation that can be installed over the top of the existing roof without requiring the old panels to be removed. The cost is relatively inexpensive, the labor is greatly reduced and the chance for water damage is reduced exponentially. A huge additional advantage is that cool-scape® PVDF “cool” paint systems used on AMS panels have an optional 35 year warranty with an expected life of 40-50 years or more.

Option 1 - Tall panel clips over existing roof panel

This system is feasible when you have:

• An industry standard, through-fastened “R” type panel with 1 ¼” tall ribs 1’-0” on center • The new panel options available are: Standing Seam II, Standing Seam 360, Loc Seam, or Loc Seam 360.

The existing roof system is a through fastened “R” type roof. The existing roof’s side lap or stitch fasteners must be removed. It is recommended that the fastener holes be covered with tape.

Safely and Economically

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Re-roofing a Metal Building

Step 1 - The new roof system’s panel attachment clips are fastened directly to the existing roof purlin. Current design codes may require more frequent panel attachment points in the corner and edge zones. Consequently, a cold formed angle can be added to the corner and edge zone areas for additional panel clip attachment.

AMS engineers will design sizes, thicknesses, and locations where reinforcement angles are needed. These angles are simply fastened into the existing purlin.

Step 2 –Itisrecommendedthatfiberglassinsulationbeinstalled over the existing roof to minimize condensation in the roof cavity and reduce “roof rattle” (insulation not shown for clarity). The new standing seam metal roof system attaches to the existing roof using a tall panel attachment clip that is fastened into the existing purlin or into additional reinforcing angles added by AMS design.

Thistallpanelclip,wheninstalled,orientstheflatpanofthenew roof panel approximately 1/8” to ¼” above the rib of the existing roof panel.

Safely and Economically

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That is basically all that is required to install a new standing seam metal roof system over an existing leaking roof thus creating a new weathertight building envelope without removing the old roof.

AMS will provide materials, engineering and construction drawings complete with installation details necessary for the installation of the new roof from start to finish. ThenewAMSengineeredroofsystemalsoincludesallflashingnecessary for transitions to the existing structure.

Option 2 – Clips and Purlin Subframing System

This system is feasible when you have:

• An existing corrugated roof system or an existing standing roof system that has a seam taller than 1 ¼”. • The new roof panel options available are: Long Span III, Standing Seam II, Standing Seam 360, Loc Seam, or Loc

Seam 360.

An existing roof that is a metal roof system, with ribs taller than 1 ¼”, fastened to structural zee or cee members.

Step 1 – Cold formed L shaped clips are attached through the existing panels into the existing secondary framing members below. AMS engineers will design sizes, thicknesses, and locations where clips, purlin members and if applicable, additional purlin members, are required.

Step 2 – Typically, 4” zee purlin members and 4” eave struts are attached to the L shaped clips creating a new purlin subframing system for attachment of the new metal roof panels.

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Re-roofing a Metal Building Safely and Economically

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Step 3 – The new roof panels are installed over the new purlinframingsysteminaccordancewiththespecificpanel’stypical attachment details. New LongSpan III, Standing Seam II, Standing Seam 360, Loc Seam or Loc Seam 360 roof panel systems are available for this application.

The new purlin members raise the new panel above the seam of the existing roof and provide a structural framing systemforattachmentofthenewroofsystem.Itisrecommendedthatfiberglassorrigidinsulationbeinstalledoverthenew purlin in the cavity between the existing roof and the new roof system to minimize condensation and to reduce “roof rattle”. Additionally, the insulation with increase the structure’s thermal resistance. (insulation not shown for clarity)

Both Option 1 and Option 2 can be ordered through AMS as an engineered system. All you need to do is, provide us drawings or a sketch of the existing structure, including existing panel type, and we will provide an engineered roof system to install over the existing roof panel system. We will provide design engineering, calculations, construction drawingsand installationdetails that define theassemblyprocessaswell asprovidingallmaterial necessary.Thedesign of the existing structure is the responsibility of the contractor. AMS does not design the attachment to the existing structure.

Call and we will explain this system further. It is a new unique way to solve a growing challenge.

1150 State Docks RoadEufaula, AL 36027

Phone 888.621.5020 Fax 334.687.0298

Form #SPOAMSRR4

Re-roofing a Metal Building Safely and Economically

www.ametalsystems.com

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