Bonus Room & Garage Insulation in Overland Park, KS

Bonus room and garage insulation solves one of the most common complaints in Johnson County homes from the 1990s and 2000s: the room over the garage that is too hot in summer and too cold in winter. That room has unheated garage space below, attic space behind its kneewalls, and often a sloped ceiling that follows the roof. Each of those surfaces needs to be sealed and insulated.

The floor

The floor framing over the garage often has batts that sag or do not fill the cavity. Air moves through the gaps. Spray foam or dense-packed insulation in the floor, with the band joist sealed, stops the drafts and keeps garage exhaust out.

Kneewalls and sloped ceilings

Kneewalls separate the room from attic space. They often have batts with no backing, so attic air washes through them. We seal and insulate the kneewalls and the floor behind them, and insulate sloped ceilings where we can reach.

The garage

Insulating garage walls and ceilings keeps the garage more moderate and protects the room above. Closed-cell or open-cell foam both work. If you heat the garage as a shop, we size the thickness to that.

Why bonus rooms are hard

A bonus room is wrapped by unconditioned space on several sides. Below it is the garage. On the sides are kneewalls with attic behind them. Above it is often a sloped ceiling that follows the roof, with only a few inches between drywall and roof deck. Builders usually fill those spaces with batts, but batts with no backing let attic air move through them, and sloped ceiling bays are hard to fill completely. Air from the garage and attic finds its way in along the edges.

The fix, step by step

We start in the garage ceiling, opening it where needed to fill the floor framing with foam or dense-pack, and we seal the rim at the garage wall. In the attic behind the kneewalls, we either seal and insulate the kneewall itself, adding a rigid backing, or we move the insulation to the roofline over that section. For sloped ceilings, we use foam where we can reach and dense-pack where we cannot. Then we seal the joints where the room meets the attic.

Ductwork to bonus rooms

Bonus rooms often get their air through long duct runs in the attic, sometimes kinked or poorly sealed. We point out duct problems we see so an HVAC contractor can fix them while the insulation work is planned.

Shared walls

The wall and door between an attached garage and the house should be sealed to keep exhaust out. We check the door and seal the wall. Get a free estimate