The room that never feels right
Garage & Bonus Room Insulation in Olathe, KS
Seal the floor, kneewalls and slopes around the bonus room.
- Free on-site estimates
- Written quote with foam type, depth and R-value for each area
- Attic bypasses, rim joists and moisture checked first
Garage & Bonus Room Insulation That Fixes the Problem Room
Garage and bonus room insulation targets one of the most common complaints in Johnson County homes: the room over the garage that is too hot in summer and too cold in winter. That room has unconditioned space on almost every side: the garage below, attic spaces behind the kneewalls, and roof slopes above. Gaps in any of them let outside temperatures in.
The floor
The floor over the garage is often insulated with batts that sag or have gaps. Spray foam fills the joist bays and seals out garage air and fumes. ENERGY STAR recommends R-19 for floors over unheated space in zone 4A.
Kneewalls and slopes
Kneewalls are short walls with attic space behind them. Batts there often fall out or never touched the drywall. Foam on the kneewalls, the attic floor behind them and the sloped ceilings closes those leaks.
The garage itself
For a garage used as a shop or gym, foam or dense-pack in the walls and insulation above the ceiling make it usable longer into the season. We also check the door between the garage and the house.
Before we start
We look at the HVAC supply to the room. Sometimes a room is short on airflow as well as insulation, and we will tell you if that seems to be the case.
What This Covers
What we insulate.
Bonus room floor
Foam in the joist bays over the garage.
Kneewalls and slopes
Foam on kneewalls, behind them and in sloped ceilings.
Garage walls and ceiling
Foam, dense-pack or blown-in, depending on access.
Shared walls
Sealing walls between the garage and living space.
Published Garage & Bonus Room Insulation Costs
| Job | Range and source |
|---|---|
| Spray foam, installed | $1.50 to $5.00 per sq ft (HomeGuide) |
| Open-cell / closed-cell | $1.50 to $3.50 / $3.00 to $5.00 per sq ft (HomeGuide) |
| About 1,000 sq ft | $1,500 to $5,000 (HomeGuide) |
| Blown-in, per sq ft | $1.00 to $2.80 (HomeGuide); $1.65 to $3.80 (Fixr) |
| Typical spray foam minimum | $1,000 to $2,000+ (HomeGuide) |
General ranges from HomeGuide (2026) and Fixr (2025), not specific to bonus rooms. Access, room size and whether ceilings must be opened change the cost. We look first, and the written estimate is your price.
How We Fix a Bonus Room
1. Inspect
Check floor, kneewalls, slopes, attic access and HVAC supply.
2. Quote
Each surface priced separately.
3. Open and spray
Access the floor from the garage ceiling or above; spray kneewalls and slopes.
4. Close up
Patch the garage ceiling if opened; clean up.
Garage & Bonus Room Insulation Questions
Why is my bonus room hot?
It has unconditioned space below, behind and above it. Gaps in any of those let heat in.
Do you have to open the garage ceiling?
Often, to reach the floor bays. We patch it afterward, or you can leave it for your drywall crew.
Will insulating the floor stop exhaust smell?
Sealing the floor and shared walls closes most paths for garage air.
Can you insulate a detached garage?
Yes, walls and roof or ceiling.
Garage & Bonus Room Insulation Service Areas
- Spray Foam Insulation in Olathe, KS
- Spray Foam Insulation in Lenexa, KS
- Spray Foam Insulation in Shawnee, KS
- Spray Foam Insulation in De Soto, KS
- Spray Foam Insulation in Gardner, KS
- Spray Foam Insulation in Edgerton, KS
- Spray Foam Insulation in Spring Hill, KS
- Spray Foam Insulation in Paola, KS
- Spray Foam Insulation in Louisburg, KS
- Spray Foam Insulation in Osawatomie, KS
- Spray Foam Insulation in Belton, MO
- Spray Foam Insulation in Raymore, MO
Get a Garage & Bonus Room Insulation Estimate
Get a written quote for your bonus room or garage.