Building Envelope Solutions
Two ways to insulate walls
Closed walls: drill and fill
If your walls are finished, we don’t open them. We drill small holes into each stud bay, blow in dense-pack cellulose or fiberglass until the cavity is full, then plug and patch the holes. From outside, we can often work through the siding instead, so the inside stays untouched. See blown-in insulation.
Open walls: during renovation
When walls are open to the studs, it’s the best time to insulate. Closed-cell spray foam gives the most insulation in a thin wall and seals every gap. Mineral wool batts are a good choice for fire resistance and sound. See Rockwool soundproofing.
Is my wall empty?
Signs include outside walls that feel cold to the touch in winter, rooms that never warm up, and drafts at outlets on exterior walls. We can check by removing an outlet cover or drilling a small test hole.
Which walls to insulate
For energy savings, the priority is the exterior walls: the ones between heated rooms and outside. Interior walls don’t need insulation for energy, but some people insulate them between bedrooms, bathrooms or home offices for quiet.
Brick and masonry buildings
Many brownstones and apartment buildings have solid masonry walls with plaster on furring strips. These need care, because insulating them the wrong way can trap moisture in old brick. We’ll look at the wall and tell you what’s safe for it. Often the roof and air sealing give more savings for less money.
Common questions
Will I see the holes? Interior holes are plugged, patched and ready for paint. Outside, we work behind removable siding where we can.
How long does it take? A typical house is done in one or two days.
Is there a charge for the estimate? No. Call (347) 200-5089.