How to Guide

Wall Construction

ENGINEERED WOOD CONSTRUCTION GUIDE

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FORM NO. B360P

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WWW.APAWOOD.ORG

A single layer of wood structural panel siding, since it is strong and rack resistant, eliminates the cost of installing separate

structural sheathing or diagonal wall bracing. Panel sidings are normally installed vertically, but may also be placed hori-

zontally (long dimension across supports) if horizontal joints are blocked. Maximum stud spacings for both applications are

given in Tables 19, 20 and 21.

When installing panel or lap siding over rigid foam insulation sheathing, drive the nails flush with the siding surface,

but avoid over-driving, which can result in dimpling of the siding due to the compressible nature of foam sheathing.

Sidings are occasionally treated with water repellents or wood preservatives to improve finishing characteristics or mois-

ture resistance for certain applications. If the siding has been treated, allowing the surface treatment to dry will avoid

solvent or chemical reaction with the foam sheathing.

When rigid foam insulation sheathing is used, building codes also generally require installation of 1/2-inch gypsum wallboard,

or other materials of the required thermal barrier rating, on the inside surface of the wall for fire protection.

See Figures 8 through 12 for panel and lap siding installation recommendations for the Sturd-I-Wall system or for siding

installed over nailable sheathing. See APA’s Build A Better Home: Walls, Form A530, for additional recommended details to

avoid moisture penetration in walls.

All panel siding edges in Sturd-I-Wall construction should be backed with framing or blocking. Use nonstaining, non-

corrosive nails as described in Tables 19, 20 and 21 to prevent staining the siding.

Where siding is to be applied at an angle, install only over wood structural panel sheathing.

Note: Gluing of siding to framing is not recommended due to the increased potential for panel buckling.

Panel siding meets code

requirements for wall bracing

1/8" spacing is recommended

at all edge and end joints unless

otherwise indicated by panel manufacturer

Building paper or code-

recognized weather-resistive

barrier required behind siding

APA RATED SIDING panels.

All edges supported by framing

or blocking.

FIGURE 8

APA STURD-I-WALL (Vertical Panel Installation)

6" minimum clearance,

siding to grade