Installation Guide

Foam Over Studs - Installing STYROFOAM* Residential Sheating, STYROFOAM Tongue

& Groove, STYROFOAM DURAMATE* Plus, STYROFOAM Square Edge, TUFF-R*, Super

TUFF-R*, or THERMAX* - Installation of Foam Sheathing as a Weather-Resistive barrier

1. Mark the Dow insulation boards by dragging the hook of a measuring tape along the surface of the board while

holding the other end of the tape at the desired measurement.

2. Dragging the hook will create a small mark to follow when cutting. Set the board on a flat, sturdy surface for ease

and safety in cutting. A pair of sawhorses is usually sufficient for waist-high work. Follow the mark left by the tape

edge, holding the knife low against the board. Don't cut all the way through; just make a deep impression with the

knife blade. Once the entire measured line has been scored, simply snap off the piece, over the edge of your work

surface.

3. Install a code-acceptable corner bracing such as diagonal metal strapping, let-in wood or wood structural sheathing

(wood sheathing should be covered by Dow insulation boards to provide full wall insulation). Note: Dow insulation

boards are not structural panels.

4. Install Dow 4’x8’ and 4’x9’ insulation boards vertically with long joints in contact with one another and bearing

directly on the framing members. Install Dow 2’x8’ insulation boards horizontally on the framing members.

5. Secure Dow insulation boards using 1 3/4" ring shank nails or staples with a 1” diameter plastic cap or equivalent

fastener long enough to penetrate framing a minimum of ¾”. Nails or staples should not be over-driven. Secure the

4’x 8’ and 4’x 9’ boards 12" o.c. around the perimeter and 16” o.c. in the field or as required by the code authority

having jurisdiction. Secure 2’x 8’ boards 12” o.c. on each stud (3 fasteners per stud) or as required by the code

authority having jurisdiction.

6. Tape all insulation joints and penetrations using nominal 3” STYROFOAM* All-Purpose Tape (ie. horizontal and

vertical seams as well as exterior penetrations from pipes, dryer vents etc.). In the case of exterior penetrations only,

seal around opening with an all-weather sealant (ie. silicone caulk, Dow GREAT STUFF™ Gaps & Cracks sealant)

prior to taping.

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Foam Over Studs - Installing STYROFOAM* Residential Sheating, STYROFOAM Tongue & Groove, STYROFOAM DURAMATE* Plus, STYROFOAM Square Edge, TUFF-R*, Super TUFF-R*, or THERMAX* - Installation of Foam Sheathing as a Weather-Resistive barrier 1. Mark the Dow insulation boards by dragging the hook of a measuring tape along the surface of the board while holding the other end of the tape at the desired measurement. 2. Dragging the hook will create a small mark to follow when cutting.
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7. For window installation the nailing flange is set against a silicone bedding and fastened to the framing with 1½” galvanized roofing nails, 3” from each corner and 8” on center. A 3” wide butyl flashing can be used to seal the sill of the window and a 2” wide butyl flashing can be used to seal jambs and heads. Refer to window manufacturer’s instructions for proper window installation. 8.