Roofing: asphalt, metal, cedar, synthetic, and flat.

Bottom to top, and what we do at each one.

• The deck

  What everything else fastens to

  Every shingle manufacturer requires a solid, sound deck as a condition of the warranty, and no manufacturer will honor a claim on shingles fastened into punky sheathing. On a tear off we walk the whole deck before anything goes back on, mark the soft sheets, and replace them. If we can see it, it goes in the estimate as a unit price, so a surprise costs a known number instead of a change order.

• Ice barrier

  The Minnesota layer, and yes, everyone calls it Ice and Water Shield

  Grace makes a product called Ice and Water Shield and the name stuck to the whole category, the way people say Kleenex for tissue. Ask ten roofers in this state and ten of them will use it that way, us included. What it actually is: a self adhering membrane, run from the lowest edge of the roof up past the inside face of the exterior wall, so ice backing water up the slope has nothing to get under.

  Manufacturers publish how far it has to run, and in a cold climate the answer is farther than most people install. We run it to the manufacturer requirement rather than to the minimum, and on deep overhangs that means more than one course.

  On a house with deep overhangs that means more than one course, and we run it that way. Ice dams push water backward up the slope, and this membrane is what keeps that water off your ceiling.

• Underlayment

  The layer people cheap out on

  

  Felt is the old answer and it still works where it belongs. Synthetics are lighter, tear resistant, safer to walk, and they hold up to weather exposure while a job is open. What matters more than the brand is matching the underlayment to the covering going over it and to how the assembly needs to dry.

  Breathability is the part that gets skipped. A fully vapor closed underlayment under the wrong assembly traps moisture in the deck, and on an unvented or poorly vented roof that is how you rot sheathing from the inside while the shingles look new. Metal, tile, cedar, and asphalt all want different things underneath them. We pick the underlayment for your roof rather than whatever came off the truck.

• The covering

  Asphalt is one kind of shingle, not the only kind

  Architectural asphalt is the workhorse here and it earns that. It is not the only option and we install the others.

  Standing seam and metal shingle systems shed snow and last decades. Cedar shakes and shingles look like nothing else and ask for maintenance in return. Synthetic and composite shingles fake slate and shake convincingly with better impact numbers. Slate and tile show up on the buildings that deserve them. On low slope, a membrane, which gets its own section below.

• Fastening

  Nail zone and manufacturer spec, confirmed

  Every shingle has a nailing zone, a fastener count, and an exposure printed by the manufacturer. Miss the zone by an inch and the shingle is not fastened the way it was tested, even though the roof looks finished from the ground.

  So we check it. Our crews are inspected during the install, not after, and we confirm the nail zones are being hit and that the roof is going together to the manufacturer's printed specification. That is the difference between a roof that carries a warranty and a roof that has a warranty document in a folder.

Most roofs fail from the inside.

Warm moist air from the house rises into the attic, hits the cold underside of the deck, and condenses. That is frost in an attic in January and stained sheathing in April. It is also how ice dams form, because a warm deck melts snow that refreezes at the cold eave.

The University of Minnesota Extension has the best plain language work on this for our climate, and their order of operations is the right one. Seal the air leaks from the house into the attic first. Insulate to the current standard second. Ventilate third. Ventilation cannot fix a leaky, under insulated ceiling, it can only carry away what is already up there.

When we vent, we balance it. Intake at the soffits, exhaust at the ridge, sized together. Ridge vent with blocked or painted over soffit vents does not exhaust an attic, it pulls conditioned air out of your house through every ceiling penetration you have. We check the intake before we sell you exhaust.

Flat roofs do not leak because they are flat.

They leak because the water has nowhere to go. A low slope roof is designed to drain, and drainage is slope, drain placement, and whether the insulation under the membrane still holds its thickness.

Water still standing forty eight hours after the rain stopped is the signal. It loads the structure, ages the membrane, and in this climate it freezes and works the seams. Patching under a pond treats the symptom.

What we do is find the actual drainage problem, then install a single ply membrane system sloped to drain, with the perimeter and every penetration detailed as part of the system rather than sealed after the fact.