On this page
Introduction #
A welded hollow metal frame arrives from the shop as one unit, head and jambs welded together, and it goes into the rough opening before drywall is hung so the rock can butt into the frame's return. The Steel Door Institute publishes the standards these frames are built and installed to; this guide is the field sequence. This is the frame-only job: setting and anchoring the frame square, plumb, and level in the opening. The slab goes in on a separate trip once the frame is set, and hardware, hinges, lockset, closer, gets its own guide.
The step-by-step here, the return clearance, the wood spreader, the bracing sequence, the floor anchors, and the plumb and square check, follows ANSI/SDI A250.11, Recommended Erection Instructions for Steel Frames, the Steel Door Institute's installation standard for steel frames.
Welded and knock-down hollow metal frames are two different jobs with two different sequences. This guide covers the welded frame, set before drywall goes up. For a frame that installs after drywall is finished, see How to Install a Knock-Down Hollow Metal Frame.
Before You Begin #
Before you set a welded hollow metal frame, confirm that the following prerequisites are complete.
Prerequisites #
- The opening is framed in wood studs. This guide is not for masonry: we do not set hollow metal frames into block or concrete, and there are no masonry anchors, concrete screws, or grout anywhere in this sequence.
- Framing is complete and square, with the rough opening sized for the frame.
- Drywall has NOT been hung yet. Welded frames are set at the framing stage, before drywall goes up, so the rock can butt into the frame's return.
- The frame and its strap anchors are on site and match the opening's schedule.
What You Need To Know #
- The frame is set plumb, level, and square, then anchored directly. There are no shims on a welded frame.
- This is a frame-only job. It stops once the frame is anchored. The slab is a separate trip, and door hardware installs under its own guide.
- Welded frames anchor through strap anchors on the back of the jambs, into the wood studs. There is no adjustment for square once the frame is anchored, so get it right before the first screw goes in.
Tools #
- 4-foot level, to check the frame plumb and level.
- Framing square, to check the frame square in the opening.
- Tape measure, to center the frame in the rough opening and check margins.
- Drill/driver or screw gun, to drive the strap anchor screws.
Materials #
- Welded hollow metal frame, per the opening's door schedule.
- Strap anchor screws: #8 x 1 inch modified truss head, stainless, self-tapping (the low round head is what reads as flat in the field)
Installation Steps #
Step 1. Position the Frame in the Rough Opening #
Set the frame into the rough opening, centered with an even gap on both sides. The frame's return is built to the finished wall thickness called out on the door schedule, so once the frame is centered, the gap between the return and each stud face should equal the thickness of the drywall that goes up later. That's the clearance the strap anchors get bent around, so the rock tucks straight into the return with nothing packed in behind it. Check the frame plumb and level before you touch a fastener.
Step 2. Hold the Frame While You Anchor It #
Before any screws go in, get the frame steady and plumb. Check the base of the frame for a factory spreader bar first. Welded frames often ship with one to hold the jambs at width in transit, and per ANSI/SDI A250.11 it has to come off, cut with a saw or chisel, filed flush, and the bare metal touched up with primer, before the frame goes into the opening. In its place, cut your own wood spreader at least 1 inch thick, the same width as the door opening at the head, notched to clear the stops, and set it between the jambs at the floor. Leave it in until the frame is fully anchored. With the spreader holding the width, brace the frame with diagonal braces running down to the floor or adjacent framing, set perpendicular to the wall so they don't fight the anchors going into the studs. Don't fasten bracing straight into the frame face, it can void the frame's listing. On openings wider than 4 feet, add a vertical brace under the head as well. That combination, spreader plus braces, holds the frame steady while you drive the first anchor screw.
Step 3. Anchor the Strap Anchors to the Studs #
Drive a strap anchor screw at the first strap, rechecking plumb, then work down the hinge jamb before moving to the strike jamb. Keep every screw flush so nothing interferes with the frame's return.
Step 4. Anchor the Base of the Jambs #
With the jambs strapped to the studs, address the base of each jamb next. Each jamb gets its own anchor into the floor, it doesn't ride on the strap anchors alone. Most welded frames come from the shop with a base anchor already on the jamb, fasten that to the floor. If a jamb didn't ship with one, add a floor anchor at its base before you move on.
Step 5. Final Check #
Before you call the frame set, check the head for level end to end and each jamb for twist. Lay a straightedge across the face of both jambs, if there's no twist it sits flat with no gap. Check both jambs plumb with a level, and measure the opening width at the top, the middle, and the bottom, those three numbers should match. ANSI/SDI A250.11 sets the tolerance at 1/16 inch for plumb, level, and width, so if a measurement is off by more than that, the frame moved before it was anchored and needs to be reset now, it has no adjustment once it's strapped in. The frame is done once it holds plumb, level, and square with no movement when pushed.
QC / Punch Checklist #
- Frame is plumb and level, with square, even margins on both sides of the opening.
- Head is level and both jambs show no twist.
- Every strap anchor screw is driven flush and solid into a stud, none missed or stripped.
- Frame has no movement when pushed at the head or either jamb.
- No shims anywhere in the opening.
