The steel and wood behind a brick garage door opening

On a Kokomo brick ranch the garage door looks set into the masonry, with brick up both sides and a row of brick across the top. The door never touches any of it. What it hangs on is behind the brick, and what holds the brick up over the door is a length of steel most owners have never looked at.

What does a garage door fasten to on a brick-front house?

To wood. On a brick-front house the garage opening is framed in wood behind the brick face, with a jamb up each side and a header across the top, and every part that carries the door fastens to that wood. So a garage door replacement in Kokomo on a brick ranch starts with what the brick is hiding.

The brick itself is a veneer, one layer standing a little way off the framed wall and tied back to it. It keeps the weather off and gives the front of the house its look. It holds up nothing of the door. The tracks lag into the jambs on each side, and the spring’s center plate bolts to the header or to a spring pad, a board fastened across the framing above the opening.

The brick rarely decides the job. Two things around it do: the steel over the opening, which carries the brick above the door, and the wood inside the opening, which carries the door. Neither shows much from the driveway, and both deserve a look before a door is ordered.

What holds up the brick over a garage door, and how do you tell it is failing?

A steel angle lintel. It is an L-shaped length of steel running across the top of the opening under the first course of brick, each end resting on the brick at the sides of the opening. The wood header behind it carries the wall and roof above, and the lintel carries the brick over the door. When the steel rusts or bends, the brick above it shows it first.

Stand back far enough to see the whole width of the opening. These are the signs, and what each one points at:

• Rust staining that runs down the brick from either end of the opening, where the steel sits. Water has been reaching the steel.
• A stair-step crack in the mortar joints, climbing up and away from one top corner. The brick over that end of the lintel is moving.
• The line of brick over the door dipping toward the middle, or a gap opening between the steel and the brick above it. The steel has bent, or one end has lost its seat.
• An exposed edge of steel that looks flaky or swollen instead of flat and painted. That is rust building up in layers.

Steel that rusts grows. The rust takes up more room than the steel it came from, so a lintel rusting inside a brick wall pushes on the brick around it, which is how the cracks start, and it gets thinner as it goes. A lintel with these signs is a mason’s job, and it gets settled before the new door is measured, since setting new steel can move the top of the opening.

Why do the wood jambs inside a brick opening go soft at the bottom?

The foot of each jamb sits right at the slab, in the corner the brick return shades, and that is where splash off the driveway and the thaw puddle sit longest. Wood that stays damp at the bottom softens from the end grain up, often well before anything shows on the face.

The bottom track bracket lags into that part of the jamb, and a lag needs sound wood to bite. No door is hung on a jamb soft enough that it will not hold one. That jamb is replaced before the new door goes up.

What covers the wood between the brick and the garage door?

Capping and stop. The jambs and header are wrapped in bent aluminum or vinyl capping so no bare wood faces the weather, and a stop molding with a weatherstrip runs up each side and across the top for the closed door to press against. A bead of caulk closes the joint where the capping meets the brick.

That caulk joint is usually the first thing to open. Brick and metal move differently through a Howard County winter, and the joint between them takes the movement. Once it opens, or the capping splits at a fold or pulls loose near the slab, rain runs in behind the metal and stays there against the jamb, out of sight. That is how the foot of a jamb goes soft behind capping that still looks tidy from the street.

A new door usually gets new stop molding as well. The old stop was set to the old door’s face, close enough for its weatherstrip to touch all the way around, and a new door rarely sits in exactly the same plane. Reused stop tends to leave a gap down one side and rub the door on the other.

Can a brick garage opening be made wider or taller for the new door?

Yes. The mason goes first: the brick is cut back, a longer steel lintel is set over the new opening, and the wood frame behind it is rebuilt to the new size. That work is priced on its own.

Turning two single openings into one is the bigger version of the same job, and whether one wide door can replace a pair of singles comes down to what the post between them carries. Most brick openings keep their size, though, and the door is made for the hole that is already there. What a new two-car door costs installed here is $1,600-$2,600, with a single-car door at $1,200-$2,000.

Either way, the door gets measured last, after any mason or carpenter is done with the opening. On a brick front the measure visit reads more than the size. It looks at the steel over the opening, the wood inside it and the capping between, and a failing lintel or a soft jamb is said out loud before a door is ordered.