New build inspection · Roof and flashing
Roof and flashing defects in a new build
New roofs rarely leak through the shingles. They leak at the places where the roof meets something else, and almost all of those places are flashing details a buyer can see from the ground.
What goes wrong with roof and flashing in a new build?
Reviewed · 2026-09-03New roofs rarely leak through the shingles. They leak at the places where the roof meets something else, and almost all of those places are flashing details a buyer can see from the ground.
Why it matters
Roof and flashing in a new home
A shingle roof is a water-shedding system, not a waterproof membrane. It works because every interruption in the field of shingles is flashed so water is carried back onto the surface. Where flashing is missing, short or installed in the wrong order, water goes into the wall instead.
The failures worth knowing are concentrated in a handful of details: where a roof edge dies into a wall, where two roof planes meet in a valley, where pipes and fans penetrate the surface, and at the eave and rake edges. Most of these are visible from the driveway with a phone camera zoomed in.
Calgary adds hail. The city sits in one of the most hail-prone corridors in Canada, and hail resistance is a real specification difference between shingle products. It is worth knowing what is on your roof before you insure it.
Best moment to look
Pre-possession walkthrough
Roof details are best checked once the roof is complete and the scaffolding is gone, from the ground with a zoom lens, and again from inside the attic looking for daylight and staining.
In Alberta
Calgary sits in Canada's most active hail corridor, and severe hail events have produced some of the largest insured losses in Canadian history in this city. Shingle products carry impact resistance ratings, and some insurers price accordingly. Ask which shingle is specified on your home, what its impact rating is, and what the manufacturer warranty covers, then tell your insurance broker before the policy is bound. Roof leaks and flashing workmanship fall under the shorter workmanship period of the Alberta New Home Warranty, so a first-winter inspection matters.
How it should be built
What correct looks like
Kick-out flashing where a roof meets a wall
Without the kick-out, the whole roof edge drains behind the cladding. The flashing turns that water out onto the wall face and into the gutter.
The flags
What to look for
Each item lists what the defect is, how to spot it without tools, and the stage of construction when it is still visible. None of this replaces a licensed inspector. It makes you a useful witness on your own site.
01Missing kick-out flashing
Water and envelopeWhat it is. Where a sloped roof edge meets a vertical wall, a small angled flashing must divert water out onto the wall cladding. Without it, the entire roof edge drains straight down inside the wall. This is one of the most damaging and most commonly omitted details in residential construction.
How to spot it. Find every place a roof edge ends against a wall, typically at a garage or bonus room. At the bottom of that intersection you should see a small metal piece kicking water outward, above the gutter.
Visible at: Pre-possession walkthrough
02Step flashing replaced with a bead of caulking
Water and envelopeWhat it is. Where a roof runs alongside a wall, individual step flashings must be woven with each shingle course. A continuous strip of metal, or a line of sealant, will fail as soon as the sealant does.
How to spot it. Look along the roof-to-wall line. You should see a stepped pattern of metal under the cladding, not a single long strip and not a caulked joint.
Visible at: Pre-possession walkthrough
03Vent boots and pipe flashings not sealed
Water and envelopeWhat it is. Plumbing stacks and exhaust vents penetrate the roof and are sealed by a boot. The rubber collar is the part that fails first, and boots installed with the shingle order reversed leak immediately.
How to spot it. Zoom in on each pipe coming through the roof. Shingles should overlap the top of the boot flange and the boot should overlap the shingles below it. Look for cracked or lifted collars even on a new roof.
Visible at: Pre-possession walkthrough
04Missing drip edge at eaves and rakes
Water and envelopeWhat it is. Drip edge is the metal at the roof perimeter that keeps water from running back under the shingles and rotting the sheathing edge and fascia. It is inexpensive and sometimes skipped.
How to spot it. Look along the bottom edge of the roof and up the gable edges. You should see a thin metal lip beneath the shingle edge, above the gutter.
Visible at: Pre-possession walkthrough
05Valley detail done badly
Water and envelopeWhat it is. Valleys carry the most concentrated water on the roof. Whether woven, closed cut or open metal, the detail has to be consistent and the cut line clean, with underlayment beneath.
How to spot it. Look down each valley. The line should be straight and uniform, shingles should not be short of the centre, and there should be no exposed fasteners in the water path.
Visible at: Pre-possession walkthrough
06Exposed fasteners and shiners in the attic
Water and envelopeWhat it is. Nails driven through the roof surface outside the sealed zone are a leak path. Nails that missed the truss entirely show as bright points in the attic and indicate poor fastening.
How to spot it. From the ground, look for nail heads sitting proud on the shingle surface. In the attic with the light off, look for daylight and for rows of nail points that missed framing.
Visible at: Pre-possession walkthrough
Put it in writing
Questions for the builder
Ask these by email rather than on site. A written answer is a record, and a builder who answers clearly in writing is telling you something useful about how the rest of the build will go.
- Which shingle product and impact rating is specified on this home?
- Is kick-out flashing installed at every roof-to-wall intersection?
- What underlayment and ice-and-water protection is used at the eaves and valleys?
- Who do I contact for a roof leak, the builder or the roofing subtrade, and for how long?
FAQ
Questions about roof and flashing
It is a small angled piece of metal at the bottom of a roof-to-wall intersection that pushes water away from the wall and into the gutter. Without it, water running down the roof edge is delivered behind the cladding, where it stays. It causes a disproportionate share of serious wall rot, it costs very little, and it is invisible to most buyers, which is why it is worth learning to look for.
Calgary experiences severe hail more often than almost anywhere in Canada, and higher impact-rated shingles are designed to survive it better. Whether the upgrade pays depends on the product, the price and what your insurer will recognise. Ask the builder what is specified as standard and ask your broker whether a higher rating changes your premium before you decide.
Do not climb on it. Almost everything worth checking is visible from the ground with a zoomed phone camera, and the rest is visible from inside the attic. Photograph each roof-to-wall intersection, each valley and each penetration, and send anything that looks wrong to the builder in writing.
Source note
- Sources
- Alberta New Home Warranty program information
- National Building Code, Alberta Edition, as adopted for the permit in force
- City of Calgary building inspection and lot grading information
- Health Canada radon guidance for homeowners
- Jurisdiction
- Alberta, with Calgary-specific notes
- Applies to
- New residential construction purchased from a builder.
- Last reviewed
- 2026-09-03
- Limitations
- General guidance written for buyers, not a code interpretation and not a substitute for a licensed home inspector or a professional engineer. Code requirements depend on the edition in force when the permit was issued. Warranty periods and coverage depend on your own warranty certificate.
- What you should verify
- The requirements that applied to your permit, the coverage periods on your warranty certificate, and any defect with a licensed inspector before you rely on it in a claim.
Work with REP YYC
Bring your own representative to the walkthrough.
The builder's sales staff are paid to sell the builder's lots. REP YYC agents are paid by the builder too, but they work for you: lot choice, contract terms, incentives and the possession timeline. No cost to the buyer.