Garage Door Header Replacement: Cracks or Water Damage

A crack in the wall above your garage door or a soft, damp spot in the beam holding it up means one thing: shimming it and hoping isn’t going to cut it anymore. This is when a header stops being a repair job and becomes a replacement, and knowing which one you’re dealing with early is what keeps the cost down.

Crack in the Wall, or Crack in the Header?

Not every crack above a garage door means the beam itself is failing. A single hairline crack in stucco or paint, especially one that hasn’t changed in months, is often just surface movement and nothing structural. What’s worth taking seriously is a crack that’s visibly widening, a stepped crack running through brick or block, or any crack that shows up at the same time the door stops closing flush. That combination almost always means the header underneath has moved, not just the finish on top of it.

What Water-Damaged Wood Actually Looks and Feels Like

Rot doesn’t always look dramatic from the outside. Press a screwdriver or an awl into the wood along the header. Sound wood resists it. Water-damaged wood gives way easily, sometimes crumbling instead of splintering, and it often carries a dark stain or a musty smell that a simple cosmetic dip never has. If the probe sinks in more than a quarter inch without much resistance, you’re not looking at a header that needs reinforcing. You’re looking at one that needs to come out.

Why You Can’t Just Sister a Rotted Header

Reinforcing a header, bolting a new board alongside the old one, only works when the existing wood is still sound, just undersized for the load above it. Rotted or badly cracked wood doesn’t give a new board anything solid to attach to. Screws and bolts pull straight through soft wood the same way they would through cardboard, so what looks like a repair ends up failing again within a year or two. Once the wood has actually broken down, the only fix that holds is taking the damaged section out entirely.

What Full Replacement Actually Involves

A real header replacement starts with temporary support, usually a couple of jack posts or a built stud wall set just inside the garage opening, so the structure above stays put once the old beam comes out. From there, the damaged header is cut out, a new beam is sized to carry the actual load above it, and whatever was covering the old header, siding, trim, or masonry, gets rebuilt around the new one. If water got in, whoever’s doing the work should also check the framing on either side of the header, since rot rarely stops exactly at the beam’s edges.

What It Costs When It’s an Actual Replacement

Scenario	What’s Involved	Typical Cost	Timeline
Replacement, light siding above	Temporary shoring, remove and replace beam, new vinyl or wood trim	$1,500 to $4,000	1 to 2 days
Replacement, brick or stone veneer above	Veneer removal and reset, new sized beam, mason and carpenter both involved	$5,000 to $10,000+	3 to 5 days
Replacement with nearby water damage	New header plus repair to rotted studs, sheathing, or interior drywall	$2,500 to $7,000	2 to 4 days
Replacement under a second-story load	Engineering review, permit, new beam sized to code	$8,000 to $20,000+	1 to 2 weeks

If your door has also drifted off its tracks while the header shifted, that’s priced and repaired separately from the structural work above it.

Do You Need a Permit for This?

In most places, yes. Because the header is load-bearing, replacing it counts as structural work, not routine maintenance, and most municipalities want it inspected before the wall is closed back up. A contractor who does this regularly will usually pull the permit as part of the job. If someone offers to skip that step to save time, that’s worth asking about directly, since an uninspected structural repair can complicate things later if you ever sell the house.

Storm Damage or Just Old Age? Why the Cause Matters for Insurance

Insurance tends to draw a hard line here. A header cracked or rotted by years of slow water intrusion is treated as deferred maintenance, and that’s almost never covered. A header damaged suddenly, by a falling tree limb, a vehicle backing into the structure, or wind-driven rain during a specific storm, has a real chance of being covered. If your situation fits the second category, photograph the damage before any repair starts and note the date of the storm or event, since that’s the first thing an adjuster will ask about.

Can You Still Use the Garage Door During the Repair?

Usually not for the full extent of the work. Once the old header is out, the door itself is often removed too, both to protect it and because the opening needs to stay clear for the new beam to go in. Most contractors can get a driveway-accessible opening back within a day or two even on larger jobs, but plan on parking outside for at least part of the project rather than assuming you’ll have use of the garage the whole time.

FAQ

How do I know if it’s a crack in the stucco or a crack in the header itself?

A stable hairline crack in the finish is usually cosmetic. A crack that’s visibly widening, that runs in a stepped pattern through brick, or that shows up alongside a door that no longer closes flush points to the header underneath, not just the surface.

What does water damage in a garage door header actually look like?

Dark staining, a musty smell, and wood that gives way easily when pressed with a screwdriver instead of resisting it. Rotted wood often crumbles rather than splintering the way sound, simply undersized wood does.

Can a cracked or rotted header just be reinforced instead of replaced?

Not reliably. Reinforcement works when the existing wood is sound but too small for the load above it. Rotted or badly cracked wood can’t hold screws or bolts securely, so a repair on top of it tends to fail again within a year or two.

How much does a full header replacement cost?

Basic replacement under light siding runs $1,500 to $4,000. Jobs involving brick or stone veneer typically run $5,000 to $10,000 or more, and anything under a second-story load can reach $8,000 to $20,000.

Do I need a permit to replace a garage door header?

In most areas, yes, since it’s structural work. A contractor who handles this regularly will usually include pulling the permit as part of the job.

Can I still use my garage door while the header is being replaced?

Not for most of the project. The door is often removed while the header is out, so plan on parking outside for at least a day or two even on a straightforward job.

Will homeowners insurance cover this?

Only if the damage happened suddenly, like storm damage or an impact. Damage from years of slow water intrusion or general age is treated as maintenance, which insurance typically doesn’t cover.

Who do I actually call for this, a garage door company or a contractor?

A contractor or carpenter handles the header itself, since it’s structural carpentry. A garage door technician usually comes in afterward to reset the door, tracks, and opener once the new beam is in place.

Conclusion

A crack that’s growing or wood that gives way under light pressure isn’t something a shim or a quick patch is going to solve. At that point you’re looking at a real structural replacement, not a repair, and the cost depends almost entirely on what’s sitting above that beam. Get it confirmed early with a simple screwdriver test and a look at the crack over a few weeks, and you’ll know which kind of job, and which kind of bill, you’re actually dealing with.