Most roof leaks start at a hole someone cut. A skylight, a pipe, a vent, a conduit, a drain: each one is a place where the membrane stops and a detail takes over. The detail is usually a few dollars of material and a lot of labor, and it is the first thing to fail. Coeur d'Alene sets a 60 psf ground snow load on the City sheet and rates weathering as severe, so every one of those details sees deep snow, hard freezes and fast melts.
We price penetrations one opening at a time. The owner or GC sees a number for each skylight, curb and pipe, and decides which to fix now and which to carry.
The Call: Re-Flash, Rebuild or Replace
A failing opening gets one of three treatments. Re-flashing replaces the flashing and sealant and leaves the curb and unit in place. Rebuilding replaces the curb, builds it taller if snow is burying it and re-flashes the opening. Replacing removes the unit and installs a new one with a new curb and flashing. Cost climbs with each step, and so does the life of the fix.
The choice depends on the unit and the curb. A skylight with clear glazing, a sound frame and a failed flashing is a re-flash. A skylight with crazed or yellowed glazing, a cracked dome or a leaking frame is a replacement. A pipe with a cracked boot is a boot replacement. We open the detail, photograph what is under it and write the call for each opening.
The tools are simple: a flat bar, a moisture meter, a camera and a tape. We lift the counterflashing, check the base flashing, probe the curb for soft wood or crushed insulation and look at the membrane wrap at the corners. Water that has been getting in for a season leaves a pattern in the layers, and the pattern tells us whether the leak is at the flashing or farther up. A skylight that leaks at the top is often a counterflashing problem. One that leaks at the bottom is often a curb that holds water.
What It Costs: Per Opening, With Access
Each opening is its own line. A pipe boot is the cheapest. A curb re-flash on a rooftop unit is next. A skylight replacement with a new curb is the largest, and it carries a fall protection line, because skylights are a fall hazard and the crew installs guards or screens before work begins. If the interior has finishes below the skylight, protection and cleanup are separate lines.
Where openings are numerous, a bulk price per type makes sense: so many boots at one price, so many curbs at another. A GC bidding a reroof should carry penetrations as a separate unit-price schedule, since the count on the plans is often lower than the count on the roof. A quantity that comes in higher at tear-off is a change order, and the unit price makes it simple to agree before the work. Our rooftop equipment curbs and supports scope covers the heavier units that sit on larger curbs.
What the Code Sheet Says: Snow Loads Hit Curbs
A skylight or curb sticks up from the roof and catches drifting snow on its windward side, building a drift pocket. Wet snow is dense, about 20 pounds per cubic foot when saturated, so that pocket is a real load on the glazing and the flashing, and the city's required ice barrier underlayment shows how seriously refreezing meltwater is taken at roof edges.
Glazing is rated for load, and the frame must carry the drift. A curb that is only six or eight inches tall can be buried by a heavy winter, so water from the melt sits against the flashing instead of running past. We check curb height against the snow history of the site and recommend raising it where the flashing is regularly buried. Snow depth climbs as you go east along I-90, from about 59 inches a year in Post Falls to about 76 in Wallace, so the right height depends on where the building sits.
Where It Fails First: Corners, Counterflashing and Sealant
Corners go first. The membrane wraps a curb corner, and that wrap is a fold under stress as the curb moves with temperature. Counterflashing pulls away from the curb and leaves a gap. Sealant dries out and splits. Pipe boots crack in cold, and the cracks let water run down the pipe.
We look at the curb, the base flashing, the counterflashing, the sealant and the membrane within a foot of each opening. We also look at the interior for staining around the opening and for condensation on the glazing frame. A leak at a skylight can be a flashing failure, a glazing seal failure or condensation, and the fix is different for each. If the flashing has failed in several places, the flashing failure repair scope covers the wider area. In a dry summer, leak repair can trace a leak to one opening in a single visit.
Alternates: Guards, Raised Curbs and Smoke Vents
Several upgrades make sense as alternates. A fall protection screen over a skylight, a raised curb with a taller flashing, a protective cap over a dome, a new vent boot in a heavier material, a heat-traced drain nearby. Each is a separate line, so the owner picks. A roof that is being replaced soon may only need a temporary fix on its openings, with the upgrades in the replacement scope.
For a tilt-up at Riverbend Commerce Park, with a large flat roof and several rooftop units, the count of openings matters more than the type. A building in Hayden with aviation or light industrial use may have unusual vents and stacks, and each gets a check. An office building with a few skylights over an atrium has the interior finish to protect, so we schedule the work around occupancy. Interior protection goes up before the first cut, with drop cloths below the opening and a catch frame where the glazing comes out, and the crew closes the opening to weather at the end of every shift. A skylight left open overnight in a Coeur d'Alene spring is a bet against the forecast.
Closeout: A Penetration Schedule
At closeout the owner gets a penetration schedule. Every skylight, curb, boot and vent is numbered on the roof plan, with its type, the fix performed, the date and a photo. When something leaks later, the schedule shows what was done at that opening and when.
This record belongs in the roof file along with the drain log. It supports the preventive maintenance walks, where we reinspect each opening, and it shortens any warranty or insurance conversation. It also helps a new GC. On a building change or a tenant improvement, the schedule shows which openings are already new and which still need attention, so the contractor does not re-flash a curb that was rebuilt last summer. Without it, every leak starts a fresh investigation.
Commercial Roofing Questions
Should I replace a leaking skylight or re-flash it?
Re-flash if the glazing and frame are sound and the flashing failed. Replace if the glazing is crazed, yellowed or cracked, or the frame leaks.
Can a pipe boot be repaired or does it need replacement?
A cracked boot is replaced. Sealant over a cracked boot is a short-term patch and does not last through a freeze cycle.
Why does the leak show up only in a thaw?
Snow melt backs up at the curb and runs through gaps the rain does not reach. A raised curb or better counterflashing solves it.
Do skylights need fall protection?
Yes. A screen or guard protects people walking the roof. We install protection before any work at the opening.
How many penetrations should I budget for?
Count them on the roof, not the plans. We provide a count and a unit price per type, so the total follows the actual number.