Erecting Wall Frames

During the detailing/fabrication process, wall frames are numbered for accurate identification. These numbers are shown on the wall frame layout plans and form part of the frame branding. Frames may have identical shapes but may differ in the configuration or internal connections. Ensure that the correct frame is used in its unique location and is facing the right direction to ensure that openings are in the correct location.

Best practice to protect wall framing from ground moisture is to install an impermeable membrane under all perimeter bottom plates fixed to concrete slabs on ground. Refer to DPC topic for further information.

All structures will require some form of tie-down between frame elements to ensure load paths are correctly resisted. When tying down frame elements all connections should be in intimate contact. Any significant gaps (> 3 mm) should be packed e.g. gaps between bottom plates and concrete slab. Any gaps should be packed directly under the studs with a non-compressible packer. This will prevent distortion of LGS frame members.

There is a range of tie-downs available and these will vary depending upon the frame manufacturer and suppliers’ technologies.

Particular attention should be paid to:

• Ensuring that any tie-down brackets are attached to studs as noted by the frame manufacturer; 
• Bottom plate tie-downs that are under trusses (especially girder trusses), beside openings, at the ends of strap bracing and at the end of wall panels; 
• Tie-down bolts are to the frame supplier’s specification and suitable for the uplift loads at the locations indicated in installation drawings. Tie-down bolts should be installed to the slab edge distance required to meet the uplift performance and follow the installation methods specified.

Any fasteners used in hold-down connections should have equivalent durability to the frame and be corrosion protection Class 3 or better and must be compatible with steel.

Specified masonry anchors may take the form of screw anchors, dynabolts and masonry nails for internal/temporary walling. Holes need to be cleaned in accordance with anchor suppliers’ recommendations.

When fixing frames to slabs, installers may experience two types of connections:

Standard fixing through the bottom plate with screw-in masonry anchors with load transfer washer plate:

OR

Masonry anchor attaches to both stud and bottom plate and studs act as a tie-down rod for truss connections (this can improve load path capacity and can eliminate the use of tie down rods and hence save costs):

When joining wall frames together, consider the following:

• Make sure outside faces are flush and top plates level with each other.
• Review manufacturer’s specifications for fastener type and coating class and ensure these are on-site.
• Drill two hex head screws near the top plate into the corresponding frame intersections, followed by two hex head screws near the noggins. Finally, add two screws near the bottom plate or to manufacturers specification.
• Consider using “C” Clamps to hold the frames in place while they are screwed together.

Pryda has anchor systems for steel framing – refer to below Resources for catalogue.