text.skipToContent text.skipToNavigation

Garage Portal Systems on Concrete Foundations

The Strong-Wall® Wood Shearwall garage portal system provides higher shear capacity with reduced concrete anchorage requirements. Portal walls may be used in single- or double-portal applications and shall be installed with a minimum 3 ⅛ single- or multiple-ply header depending upon loading and span requirements.

Codes: ICC-ES ESR-2652, City of L.A. RR25730

Garage Header Rough Opening Height
Model No. H Curb (in.) Rough Opening Height (in.)
WSW12x7
WSW18x7
WSW24x7

6
6'-11½ 1
7'-0 1
WSW12x7.5
WSW18x7.5
WSW24x7.5
0 7'-1½
WSW12x8
WSW18x8
WSW24x8

6
8'-2¾2
8'-3¼2
  1. If required rough opening height exceeds table value, specify next taller panel and trim as necessary. The Strong-Wall Wood Shearwalls may be trimmed to a minimum height of 74½".
  2. Furring down garage header may be required for correct rough opening height.
  3. WSW24x7 and WSW24x7.5 must be trimmed from a WSW24x8 shearwall..

Installation

  • Portal-frame connection kit is required for portal-frame applications.
  • All panels may be trimmed to a minimum of 74½". Trim height from top of panel only, do not trim from sides or bottom. Drilling holes in the Strong-Wall Wood Shearwalls is not allowed except as shown on page 42.
  • Anchor-bolt nuts should be snug tight.
  • Maximum shim thickness between Strong-Wall Wood Shearwalls and the top plates or header is ⅞".
  • Standard top-of-wall connections install with nails.
  • Walls may also be used in 2x6 wall framing. Install the panel flush to the outside face of the framing and add furring to the opposite side.
  • Walls may be installed with solid or multi-ply headers, see page 47 Detail 4, 5/WSW4 for fastening and furring requirements.
Single-Portal-Installation C-L-WSW16
Portal Frame Connection Kit
Model No. Contents
WSW-PK 4 (10 Gauge) WSW-PS Straps
  1. Portal-frame connection kit comes with panels that are 100" or less in height. The kit must be ordered separately for panels over 100" tall.

Portal Design Information

A portal frame under lateral loads causes the portal header to experience internal stresses in addition to those created by the primary loads (live, dead and snow). These additional stresses are called induced forces and must be considered when designing portal headers. To account for the induced forces from lateral loads, a concentrated end moment equal to the top-of-panel moment must be placed at the end of the beam that is connected to the WSW panel. For WSW12 and WSW18 panels, the moment induced into the portal header must be taken as 20% and 10%, respectively, of the total lateral moment. The total lateral moment is calculated as the design shear times the panel height. For headers with typical residential uniform loads, the induced moment and shear forces from a portal-frame system do not control the design. This is due to the 1.60 load duration factor (CD) used in design and the induced stresses from wind and seismic loads.

The lateral and vertical loads shown on page 17 for portal frames assume that the header size falls within the portal-frame parameters listed in the table.

Strong-Wall® Wood Shearwall Portal Header Design Parameters
Header Design Parameter Allowable Range
Width 3 ⅛" – 5 ½"
Depth 9¼" – 18"
Clear Span 8' – 18' 6"
K 90 lb./in. – 4,000 lb./in.
  1. Single- or multiple-ply header members may be used.
  2. Secondary moment, shear and axial forces shall be considered in header design.
  3. Header design shall be by Designer and assume gravity loads only induce simple span moments in beam.
  4. Header stiffness (K) for use in WSW portal system may be determined using the following equation: K = (E x b x d3) / 12L3 where:
    E = Header modulus of elasticity (psi)
    b = Header width (in.)
    d = Header depth (in.)
    L = Header clear span (in.)

Alternative Garage Front Options

These alternative garage-front options may be used for applications when the Strong-Wall® Wood Shearwall is installed at the full height (option 1) or without the additional Portal-Frame Kit (option 2), when higher capacity or reduced concrete anchorage is not needed. Refer to the Standard Application on Concrete Foundations on pages 12-13 for product data and allowable load values.

For Garage Wall Option 2, the Designer shall design for:
  1. Shear transfer
  2. Out-of-plane loading effect
  3. Increased overturning and drift due to additional height
Alternative Front Options C-L-WSW16
Alternate Garage Front Option 1
Alternate Garage Front Option 2

Code Reports