Copyright Goodheart-Willcox Co., Inc.
252 Section 2 Foundations and Framing
11.4 Wall Sheathing
Whether the sheathing is applied before the wall frame
is erected or after, it should always be applied before the
roof framing has begun. Sheathing adds strength and
rigidity to the wall frame. Most light frame buildings are
sheathed with plywood or OSB. The sheathing material
should carry a stamp indicating that it is rated for use as
sheathing. If sheathing grade panels are used at least on
the corners of the building, diagonal bracing should not
be required. Some plans call for rigid insulation to be
used as sheathing. In this case, either diagonal bracing
or structural panels must be used at the corners.
A new type of sheathing, sold as ZIPSytem®, is man-
ufactured with structural OSB coated with a water-re-
sistive barrier. It is also available with insulating foam
backing. This material eliminates the need for diago-
nal bracing and housewrap (discussed later). After the
sheathing is applied and the walls are erected, seams
between sheathing pieces are covered with special tape,
Figure 11‑16.
Plywood and OSB sheathing may be applied either
vertically or horizontally. The grade stamp on the panel
indicates how many studs or other supports it must
span. Generally, panels can be installed in either direc-
tion when used over 16″ OC or 24″ OC framing.
During panel sheathing installation, steps must be
taken to protect against buckling. Panels expand and
contract as moisture content in the wood changes. If
panels are “tight” and then expand, they push against
one another and may buckle from the force. When in-
stalling sheathing panels, leave a 1/8″ space between
all edges to prevent buckling as humidity in the air
changes. An 8d or 10d common nail makes a good
spacer. Sheathing should be nailed with 8d nails every
6″ along the edges and every 12″ on intermediate studs.
Where fire resistance is an important consider-
ation, gypsum boards are a common choice for wall
sheathing. Gypsum sheathing is reinforced with glass
fibers and is fire and mold resistant. It is available in
1/2″ and 5/8″ thicknesses. While gypsum sheathing
can be applied with nails, it is most often applied with
corrosion-resistant screws. It is easy to cut by scoring
and snapping, much like interior wallboard.
16d
Stagger 24uni2033 OC
16d
8d Toenail
Nail here
when space
is limited
16d
Goodheart-Willcox Publisher
Figure 11‑14. How to assemble and fasten headers, cripple
studs, and trimmers.
Plate and rough sill
layouts should match
Cripple stud
layout remains
consistent with
common stud layout
Common studs
Timur Vildanov/Shutterstock.com
Figure 11‑15. Cripple studs can be installed before the wall
section is erected. If the wall sections are first erected,
toenail the cripple studs to the sole plate.
Photo courtesy of Huber Engineered Woods, ©2020 Huber Engineered Woods, LLC.
Figure 11‑16. Coated OSB sheathing keeps water out, is
structurally strong, and improves the heating and cooling
performance of the building. Joints are sealed with tape
made for that purpose.
252 Section 2 Foundations and Framing
11.4 Wall Sheathing
Whether the sheathing is applied before the wall frame
is erected or after, it should always be applied before the
roof framing has begun. Sheathing adds strength and
rigidity to the wall frame. Most light frame buildings are
sheathed with plywood or OSB. The sheathing material
should carry a stamp indicating that it is rated for use as
sheathing. If sheathing grade panels are used at least on
the corners of the building, diagonal bracing should not
be required. Some plans call for rigid insulation to be
used as sheathing. In this case, either diagonal bracing
or structural panels must be used at the corners.
A new type of sheathing, sold as ZIPSytem®, is man-
ufactured with structural OSB coated with a water-re-
sistive barrier. It is also available with insulating foam
backing. This material eliminates the need for diago-
nal bracing and housewrap (discussed later). After the
sheathing is applied and the walls are erected, seams
between sheathing pieces are covered with special tape,
Figure 11‑16.
Plywood and OSB sheathing may be applied either
vertically or horizontally. The grade stamp on the panel
indicates how many studs or other supports it must
span. Generally, panels can be installed in either direc-
tion when used over 16″ OC or 24″ OC framing.
During panel sheathing installation, steps must be
taken to protect against buckling. Panels expand and
contract as moisture content in the wood changes. If
panels are “tight” and then expand, they push against
one another and may buckle from the force. When in-
stalling sheathing panels, leave a 1/8″ space between
all edges to prevent buckling as humidity in the air
changes. An 8d or 10d common nail makes a good
spacer. Sheathing should be nailed with 8d nails every
6″ along the edges and every 12″ on intermediate studs.
Where fire resistance is an important consider-
ation, gypsum boards are a common choice for wall
sheathing. Gypsum sheathing is reinforced with glass
fibers and is fire and mold resistant. It is available in
1/2″ and 5/8″ thicknesses. While gypsum sheathing
can be applied with nails, it is most often applied with
corrosion-resistant screws. It is easy to cut by scoring
and snapping, much like interior wallboard.
16d
Stagger 24uni2033 OC
16d
8d Toenail
Nail here
when space
is limited
16d
Goodheart-Willcox Publisher
Figure 11‑14. How to assemble and fasten headers, cripple
studs, and trimmers.
Plate and rough sill
layouts should match
Cripple stud
layout remains
consistent with
common stud layout
Common studs
Timur Vildanov/Shutterstock.com
Figure 11‑15. Cripple studs can be installed before the wall
section is erected. If the wall sections are first erected,
toenail the cripple studs to the sole plate.
Photo courtesy of Huber Engineered Woods, ©2020 Huber Engineered Woods, LLC.
Figure 11‑16. Coated OSB sheathing keeps water out, is
structurally strong, and improves the heating and cooling
performance of the building. Joints are sealed with tape
made for that purpose.