Garage Roof Replacement — Detached and Attached Garage Reshingle
The house roof is fine but the garage is curling and bare — the small tear-off that bigger roofers put at the bottom of the list, done by a crew that shows up for it.
JMB Builders does garage roof replacement across the Twin Cities metro: a detached one- or two-car garage, or the garage section of an attached house roof. We tear off the old shingles, replace soft or board sheathing, run ice and water membrane at the eaves, and reshingle with new drip edge, underlayment and vents. Small tear-offs most roofers will not schedule are our regular work. Priced per project, quoted from photos within one business day.
- Priced per project, one crew, usually one day
- Detached garages and garage-only sections
- Soft or board sheathing replaced as found
- Quote from photos in 1 business day
- Licensed MN contractor BC809005
Garage roofs get replaced on their own for a few reasons. The garage was built later than the house and is on a different clock. The house got a new roof after a hail claim and the adjuster left the garage out. Or it is a detached garage that was roofed by whoever owned the place in the eighties and never touched again. Whatever the reason, it is a small tear-off, and small tear-offs are hard to get a roofing company to schedule.
We do them the same way we do a house roof. Old shingles off down to the deck, deck checked and any soft plywood or gapped boards replaced, ice and water membrane at the eaves and in any valley, synthetic underlayment, new drip edge, starter, shingles, and a ridge vent or box vents so the garage attic breathes. On an attached garage we tie the new shingles into the existing house roof so the seam does not show and does not leak.
Older detached garages often have board sheathing with gaps between the boards. Shingles need a solid deck under them, so those roofs get a layer of plywood over the boards before the underlayment. We tell you from the photos whether yours will need it.
What you supply
- Photos of the garage roof from the yard on each side, and one close-up of the worst area
- The garage footprint, paced off or from a survey, so we can size the material; we confirm it on site
- Your shingle color choice, or tell us to match the house and send a photo of the house roof
- For an attached garage: a photo of where the garage roof meets the house roof or wall
What JMB supplies
- Tear-off of the old shingles and underlayment down to the deck, with a trailer for the debris
- Replacement plywood for soft spots, or a full plywood overlay on gapped board sheathing
- Ice and water membrane at the eaves and valleys, synthetic underlayment over the rest
- New metal drip edge at eaves and rakes, starter strip, and architectural shingles
- Ridge vent or new box vents, pipe boots and any flashing where the garage meets the house
- Step flashing and kick-out where the garage roof runs into a house wall
- Magnet sweep of the driveway and yard for nails, and photos of the finished roof in your job folder
How it is priced: per project
Quoted in writing from your photos within one business day. What moves the number:
- Roof size and pitch; a two-car detached garage is about twice a one-car
- Number of shingle layers to tear off; two-layer roofs mean more labor and more disposal
- Sheathing condition: patching a few sheets vs. overlaying a whole board-sheathed deck
- Attached garage tie-in to the house roof or a house wall, with step flashing and kick-out
- Vents, pipe boots and flashing to replace while the roof is open
- Access for the trailer and whether the roof is over a paved driveway or a back yard
- Fascia, soffit or rafter tail repair found at the eaves after tear-off
Tell us how many layers are on it now if you know, and whether the garage ceiling is finished or open; open rafters let us see the deck from below and tighten the quote.
How long it takes
One- or two-car detached garage: one day, tear-off to cleanup. Add a day when the deck needs a plywood overlay or the attached tie-in is long.
How your project works
- 1
Send photos, get a written quote
Send three photos of the space and a sentence about what you want. You get a clear, itemized quote within one business day. We only come out to measure first when the job needs a tape measure — no pressure, no games.
- 2
Pick materials, or bring your own
We help you choose profiles and materials that fit the house and the budget, or match your existing millwork exactly — or you buy the door or trim yourself and we install it. Everything is confirmed before the crew is scheduled.
- 3
Clean, precise installation
The crew shows up on time, protects floors and furniture, and installs with tight joints and consistent reveals. Photos of the finished work go in your job folder.
- 4
Walkthrough and invoice
We walk the finished work with you. If anything is not right, we fix it before we call the job done. Then one invoice, paid by check or direct deposit — no card fees, no payment links.
Situations and options
Detached garage, full tear-off
The standard job. Old shingles and paper off, deck repaired, membrane at the eaves, underlayment, drip edge and new shingles with a ridge vent. One day for most garages.
Attached garage roof only
When the house roof was done and the garage was left out, or the garage was added later. We reshingle the garage and tie into the house roof with a clean seam, or reflash where the garage roof meets the house wall.
Board sheathing overlay
Older garages with 1x boards and gaps between them get a layer of plywood over the boards so the shingles have a solid deck and the nails hold. We confirm this from a photo of the underside where the rafters are open.
Match the house shingles
Same brand and color as the house roof when it is still made, or the closest current color when it is not. Send a photo of the house roof and, if you have it, a leftover bundle wrapper with the color name.
Garage Roof Replacement — Detached and Attached Garage Reshingle: questions, answered
Can you replace just the garage roof and not the house?
Yes. A detached garage is its own roof and we replace it on its own. On an attached garage we reshingle the garage section and tie the new shingles into the existing house roof at the seam, or reflash where the garage roof meets the house wall. The new shingles will look a little brighter than the older house roof for a season or two and then blend.
Does a garage roof need ice and water shield?
Yes, at the eaves and in any valley, the same as a house. An unheated garage does not make ice dams the way a house does, but the eaves still see standing snow and meltwater backing up under the first courses. Membrane at the eaves is cheap insurance on a roof you will not touch again for years, and we run it on every garage.
Can you shingle over the old garage roof instead of tearing it off?
We tear off. A second layer hides soft sheathing, adds weight to rafters that were often undersized to begin with, and shortens the life of the new shingles because they sit on an uneven surface. Tearing off a garage roof is a few hours of work, and it lets us see and fix the deck. If there are already two layers on it, tear-off is the only option.
What if the garage roof sheathing is rotten or is old boards?
Soft plywood gets cut out and replaced sheet by sheet after tear-off. Older garages with 1x boards and gaps between them get a full layer of plywood over the boards so the shingles have a solid deck and the nails hold. We price the likely sheathing work from your photos and confirm it the morning of the job once the old shingles are off.
Can you match the garage shingles to the house?
Usually, when the house roof is a current color from a brand still being made. Send a photo of the house roof and a shingle wrapper if one is in the garage. When the exact color is discontinued we pick the closest current one and tell you it is a near match, not an exact one. On a detached garage a slight difference is rarely noticed; on an attached garage we try harder to hit it.
How long does it take to replace a garage roof?
One day for most one- and two-car detached garages, from tear-off in the morning to the magnet sweep of the driveway in the afternoon. A garage that needs a plywood overlay over board sheathing or a long tie-in to the house roof runs into a second day. We do not leave a garage roof open overnight.
Recent JMB work, from our job log
59 installs recorded across 30 Twin Cities communities since Dec 2025. Window and door installs for homeowners and for the builders and dealers we sub for. Counts come straight from our job log; no customer names.
Get a written quote for this job
Three photos and a sentence is enough. You hear back within one business day. Or text the photos to 763-204-2099.
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Read morePage reviewed September 26, 2026 · JMB Builders LLC, MN license BC809005 · All roofing pages
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