Attic Insulation & Air Sealing

Attic & roofline spray foam

A lot of houses around Pagosa don't have a flat attic at all. The ceiling is the roof: vaulted great rooms, cabin lofts, tongue-and-groove over rafters. There's no place to pile loose insulation, so the insulation has to live in the rafter bay.

 

That's a spray foam job. Closed-cell Icynene on the roof deck gives the most R-value in a shallow bay and controls the moisture that condenses on cold sheathing. Open-cell fits deeper bays and costs less where the roof design allows it. We foam the roof while the framing is open on new builds, and we can do it from the attic side on plenty of existing homes.

 

 

Blown-in top-ups for thin attics

If the house has a real attic and the insulation is just thin or settled, you usually don't need spray foam up there. Blown-in cellulose or blown-in fiberglass spreads over the joists and brings the attic back up to where it should be, at a lower cost than foam.

 

Cellulose is made mostly from recycled paper treated for fire resistance, and it settles into the gaps around wiring and framing better than a second layer of batts laid on top. We look at what's already there before recommending anything. Sometimes the right answer is a top-up. Sometimes the old insulation is doing fine and the money belongs in the air leaks instead.

 

 

Seal air leaks first to stop ice dams

Ice dams on a mountain roof start inside the house. Warm air leaks into the attic, heats the roof deck, melts the snow from underneath, and the meltwater refreezes at the cold eaves. More insulation alone doesn't fix that if air is still pouring through the ceiling.

 

So we seal first. The top plates, the wire and pipe penetrations, the chase around the chimney, the attic hatch, the can lights. Then we insulate. On a vaulted roof, the foam itself is the air seal. On a flat attic, it's canned foam and caulk at the leaks, then cellulose over the top.

 

We can't promise you'll never see an ice dam — roof design, sun, and gutters all play a part — but stopping the warm air is the part insulation can actually do, and it's the part we do on every attic we touch.

 

 

What we look at on an attic walkthrough

How thick the insulation is and whether it's settled or soaked. Where the air leaks are. Whether the soffit vents are buried, because a vented attic has to keep breathing. Bath fans that dump moist air into the attic instead of outside. And whether the ceiling is vaulted, because that changes the whole plan.

 

You get a straight read: foam the roofline, top up with cellulose, seal and leave it, or some mix. The walkthrough is free.

 

 

Attic insulation questions

 

Should my attic get spray foam or blown-in insulation?

If the ceiling is vaulted and the roof deck is the ceiling, spray foam in the rafters is usually the way. If you have a flat, vented attic with insulation that's just thin or settled, blown-in cellulose or fiberglass is usually the better spend. We tell you which on the walkthrough.

 

 

Will new attic insulation stop ice dams?

It helps, but air sealing matters more. Ice dams form when warm air leaks into the attic and melts snow from underneath. We seal those leaks first, then insulate. Roof design and sun exposure still play a part, so no one can promise zero ice.

 

 

Can you add insulation over what's already there?

Often, yes. Blown-in cellulose or fiberglass goes right over existing batts, as long as the attic can still ventilate and the old material isn't wet or moldy. If it is, we'll say so before anyone blows anything in.

 

 

What do you use for sound between floors?

For walls and stairways where noise is the complaint, we install Rockwool mineral wool batts. Foam seals air, which carries some sound, but a dense mineral wool batt is the better sound absorber.

 

 

How much attic insulation do I need at this elevation?

It depends on the roof, the ventilation, and what's already there, so we don't quote an R-value off a chart without seeing the attic. On the walkthrough we'll tell you what the attic has and what we'd add.

 

 

Book a free walkthrough

We'll look at the attic, the roofline, and the air leaks, and tell you what it's actually worth doing.

 

Spray foam insulation