Brick Veneer Support and Ledges: What Holds Twelve Tons of Brick Up, Poured Ledges, Shelf Angles, Lintels, Ties, Adding Brick to an Existing House, and Brick on an ICF Ledge

The ledge

On a new house the brick sits on a brick ledge: a step formed into the top of the foundation wall, wide enough for the brick plus the 1 in. air space, so the brick starts a course or two below the floor framing. The ledge is poured with the foundation and costs the brick nothing extra; it is a line on the foundation drawing and a different form at the top of the wall. The foundation types page covers what the foundation is doing underneath it. The code lets the brick overhang the edge of its support by a small amount; a brick sitting half off the ledge is not supported, and a mason who starts a wall that way is telling you something.

On an ICF house the ledge is formed the same way with a brick-ledge block or a ledge form at the top course, so the concrete core steps out under the brick. The brick ties screw into the plastic webs in the foam on the spacing the code wants, and the foam is the second plane of protection behind the air space. Every brick house I build goes on an ICF ledge and the details, the ledge forms, the tie spacing and the flashing over the ledge, are the business of ICFPro.ca. The eight finishes on ICF article has brick against the other seven with costs, and the ICF home building page is the wall itself.

The shelf angle

When there is no ledge, the brick sits on steel: a galvanized or hot-dipped angle, typically 4x4x3/8 or heavier as the engineer says, bolted through the foundation wall or hung from it, with the brick bearing on the horizontal leg. The schedule carries a brick ledge or shelf angle on an existing house at $45 a linear foot, bolted to sound poured concrete. On a block foundation the bolts need to hit solid, grouted cores or go through, and on a rubble or stone foundation the honest answer is often a poured curb on a new footing, which is excavation, and a different page.

Shelf angles also show up partway up a tall wall, or over a long garage door, to carry the brick above when the span is too long for a loose lintel. Every shelf angle gets through-wall flashing on top of it and weeps in the course above, because it is a horizontal surface in a cavity and water will sit on it. The brick above it also needs a soft joint under it, not mortar, so the steel can move; a mortared joint under an angle cracks the first winter. Weep holes and flashing covers the water side.

Lintels over the openings

Brick over a window or door has nothing under it, so a steel angle lintel sits in the course above the opening and carries the brick across. For a normal window span that is a loose angle laid by the mason, bearing on the brick at each end; the code wants at least 90 mm of bearing at each end, and the mason wants more. Wider openings, a double garage door or a 12 ft slider, get a heavier angle or a built-up section the engineer sizes, and sometimes a shelf angle hung from the header instead. Loose steel lintels over standard openings are in the brick rate; engineered steel over a garage door is a line on its own.

The lintel also gets flashing on top and weeps above it. A rust line on the brick under a window is a lintel that was never primed or flashed, and after thirty years the rust jacks the brick above it into a crack that follows the steel. Replacing a rusted lintel means shoring the brick above and swapping the steel, a mason and a day at the $3,500 minimum per visit, so do the whole elevation while he is there.

Ties: what keeps it from tipping

The brick stands on the ledge and would fall away from the house in the first wind if nothing held it. Metal ties, corrugated strips or wire and plate anchors, are screwed to the framing through the sheathing and membrane and bent into the mortar joints as the courses go up. On wood frame they go into studs, not sheathing alone. On ICF they screw into the webs. The code sets the maximum spacing, and a good mason puts one in every second stud every sixth course and more at corners and openings. Ties nailed into OSB between the studs are the commonest shortcut, invisible once the wall is up, which is why the inspection happens at the third course, not the last.

Adding brick to a house that has siding on it

This is the call I get most, and the answer is yes, with four things the siding never needed. A ledge or shelf angle to stand on. A wall 5 in. thicker, so the overhang, the soffit, the window frames and the door sills all have to come out to meet it. Ties through the old sheathing into the studs. And flashing at every opening on the way back, because the old windows were flashed for siding, if at all.

A 40 ft front on a bungalow, 12 ft to the eave, 420 sq ft of net wall after five windows and a door, mid-grade brick. Shelf angle 40 lf at $45 is $1,800. Vinyl tearoff 420 at $2 is $840. Brick 420 at $36 is $15,120. Soffit and overhang rework along the 40 ft, so the eave covers the thicker wall, at $18 a linear foot is $720. Extension jambs and sill extensions at the five windows at $150 each is $750. Bin $550. Total $19,780 before HST, $22,351.40 with. A new vinyl front on the same wall is 420 at $9.50, $3,990. That is what a ledge and a brick is worth on a house that was not built for one, and it is why the brick front usually gets decided at the foundation, not at the re-side.

Where the foundation is block, rubble, or has nothing above grade to bolt to, add an engineer’s visit and whatever he draws, and stop reading quotes until he has. Where there is no place for a shelf angle without undermining the sill plate, the honest answer is adhered stone veneer, which weighs a quarter of the brick and needs no ledge; the brick cost page and the brick and stone hub put them side by side.

What to check before the wall is too high to see

1. The ledge or angle is level, continuous and flashed, and the first course sits on it with no more than the allowed overhang. A tape and a photograph.
2. The angle bolts hit concrete, on the engineer’s spacing, with the angle snug to the wall, not shimmed off it on a stack of washers.
3. Ties into studs or webs, on the spacing, bent down into the joint, not left flat in the cavity.
4. Lintels bearing at least 90 mm each end, primed or galvanized, flashed on top, weeps above.
5. A soft joint under every shelf angle and at the top of the brick under the soffit, so the wall can move without cracking.
6. The air space is clear of mortar at the ledge and at every flashing.

Questions people ask

Sources and further reading

• Ontario’s Building Code, Section 9.27 Cladding: the first and second planes of protection, sheathing membrane, flashing at openings and transitions, and the clearances from grade and roofs that every siding and stucco job has to meet.
• Canada Masonry Design Centre: masonry veneer support, shelf angles, weep holes, through-wall flashing and air space, in Canadian terms.
• ICFPro.ca: the ICF walls, brick ledges and attachment details that decide how cladding goes on an ICF house.