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Roof Sealing


Sealing penetrations and terminations properly.

Roof deck covered with blue-printed Sharkskin underlayment, gray parapet walls, wooded hills and cloudy sky beyond

What roof sealing involves


The right sealant for the substrate and exposure, applied where a mechanical detail cannot do the job alone.

Sealant is a supplement to flashing, never a substitute for it.

Newly sheathed OSB roof deck marked with chalk lines beside an older gravel roof with scrap lumber
Low-slope roof stripped in patches, dark sheet torn away exposing OSB decking, satellite dish and tear-off shovel

What matters on roof sealing


Coating extends, it does not rescue

A coating over a sound, dry low-slope roof buys real years. The same coating over a roof with wet insulation underneath seals the water in and hides a problem that keeps growing.

Thickness is the specification

Coatings are specified by applied thickness, not by number of coats. Spread thin to cover more square footage, the product will not perform to anything like its stated life.

Roof Sealing on real jobs


House under construction with flat roofs covered in synthetic underlayment, metal panels stacked, scaffolding and mountains behind
House under construction with flat roofs covered in synthetic underlayment, metal panels stacked, scaffolding and mountains behind
Dark vertical pipe penetrating a gray flat roof membrane, with dark flashing material at its base
Dark vertical pipe penetrating a gray flat roof membrane, with dark flashing material at its base
Bare OSB roof deck after tear-off on a white vinyl-sided house, with drip edge and metal vent
Bare OSB roof deck after tear-off on a white vinyl-sided house, with drip edge and metal vent
Service areaSalt Lake City & surrounding counties
Covering9 counties
In the trade27 years
As Hancock Signature8 years

How the system goes together


Fasteners rust from the inside out

Screws and nails on a roof within reach of the lake air corrode faster than the same hardware would inland. A plain steel nail head disappears under a shingle and takes years off the roof’s hold without a single visible symptom. Hot-dipped galvanized or stainless where the metal is exposed is a small line item that decides whether the roof reaches its rated life.

Mixed metals make it worse

Aluminum flashing pinned with the wrong screw sets up a reaction that eats the softer metal at every contact point.

We look at the old nails

What came out of the last roof tells you what to put in the new one.

Ridge vent against box vents

A continuous ridge slot pulls air along the entire peak, which is why it outperforms a row of box vents on most houses. Box vents still win in specific situations: a hip roof with almost no ridge to cut, a roof broken into separate attic spaces that do not share air, or a low ridge where a slot would sit under drifted snow all winter.

Never mix the two on one attic

Put both on the same space and the ridge pulls its air from the nearest box vent instead of from the soffit. The attic barely moves and the roof looks correctly vented from the driveway.

What we check

  • Field condition and granule loss
  • Valleys, ridges and every transition
  • Penetrations and their flashing
  • Gutter and fascia condition

How we approach it


1

Look first

We get on the roof and read what is actually happening before quoting anything.

2

Say what we find

Photographs and a plain explanation, including when the answer is that you do not need us yet.

3

Built in sequence

Crews we hire and run, working the right detail in the right order.

4

Leave it clean

Magnet over the yard, container gone, walked with you.

Freeze and thaw works on everything

A February day here can swing forty degrees between sunrise and mid afternoon. Water gets into a nail hole, a lap, a crack in the flashing sealant. It freezes overnight and expands. It thaws and goes deeper. Multiply that by a hundred cycles a winter and small openings become real ones. It is slow, and it is the reason a roof that was fine three winters ago is leaking now.

Sealant is a maintenance item

Anything relying on caulk has a clock on it. Flashings that rely on metal geometry instead of sealant last a great deal longer.

Wind, water and dust, in that order

Ask what actually kills roofs in this part of the state and the answer runs wind first, then water that could not get away, then the grit that the wind delivered. Each one makes the next worse. A wind-broken seal lets water in. Water carries grit into a lap. Grit holds moisture against the mat. None of it is dramatic and all of it compounds.

Why we start at the edges

Perimeters and penetrations are where all three arrive together, so that is where an honest look begins.

Roofer kneeling on bare plywood roof deck beside rolls of underlayment during a tear-off

What this looks like on a real roof


There is a version of roof sealing that gets sold off a clipboard in the driveway and a version that comes off actually reading the roof. The second one costs the same and lasts.

What follows is the part most people never get told: what usually went wrong before we arrived, and what the job looks like when it is done in the right order.

Where roofs go wrong


The shortcut we see most

Coating spread thin to cover more square footage. The stated service life assumes a specified thickness, and spread thin it will not come close.

What good looks like instead

Substrate prepared, seams reinforced, product applied at the specified rate and checked as it goes on.

Signs worth a look

  • Coating chalking or wearing thin at traffic paths
  • Seams telegraphing through the coating
  • Ponding where the coating has discoloured
  • Blisters forming under the surface

What to expect


1

When coating is the right answer

On a low-slope roof that is sound, dry and draining, a coating adds real service life for a fraction of a replacement. Those three conditions are not optional.

2

Surface preparation

Most coating failures are preparation failures. The surface has to be clean and dry, seams reinforced, and any ponding addressed before product goes down.

3

What it will not do

A coating will not dry out wet insulation, correct a drainage problem or bridge a failing seam on its own. If those are present we say so rather than coat over them.

Related work


Coatings covers more than one job, and they are not interchangeable. These are the others in the same family, each on its own page.

Coatings that extend a sound low-slope roof.
Making assemblies watertight where roofs meet other things.

Questions we get asked


Not the question you had? Call the shop and ask a person. We would rather talk it through than have you guess from a website.

(801) 382-8898
Will a coating fix my leaking flat roof?

Only if the roof is sound and dry underneath. A coating extends a good roof. It seals a wet one in.

How long does a roof coating last?

It depends on the product, the thickness applied and the exposure. Applied at the specified thickness over prepared substrate, it buys real years.

What happens if you find bad decking?

We show you. The decking is only visible during a tear-off, so that is when soft sheathing gets found and replaced. We photograph it rather than just add it to a list.

What makes a Utah roof different?

Snow load, ice at the eaves, canyon wind and high-altitude sun, all on the same roof. A crew that learned roofing somewhere mild has to learn it again up here.

Will you tell me if I do not need a new roof?

Yes. Plenty of what we look at turns out to be a repair, and we say so. A roof with years left in it gets left alone, and you get the photographs either way.

Do you handle the insurance side?

On hail-damaged roofs, we work with your insurance to get the roof covered. We document the damage thoroughly with photographs, so the claim reflects what is actually on the roof.

Ask about roof sealing


Call (801) 382-8898 or send a note. We will look at the roof and tell you straight what it needs.