Run the polyethylene up the sides of the walls 3 to 4 inches and secure to the walls with construction tape.
How to insulate and level a garage floor.
The solution to this problem provided a floor that was level comfortable to walk and stand on and considerably warmer.
Insulating concrete garage floors begins with covering the entire floor with 6 mil polyethylene which will serve as a vapor barrier.
If there is a step up from the garage into the main part of the house assuming that the garage isn t detached then the insulation and new floor build up can be added to make the new rooms at the same height to the rest of the house.
Concrete is cold and hard but an insulated concrete slab can make a heated garage significantly warmer and more energy efficient.
The other consideration for floor insulation is the level of the floor in relation to the rest of the house.
How to insulate a garage floor above a concrete slab.
However an out of kilter garage floor may require leveling when two critical scenarios happen.
Overlap the seams about 6 to 8 inches and seal the seams with waterproof construction tape.
When converting a garage space into a living area installing a framed wood floor offers an opportunity to add insulation from the cold concrete slab access for electrical circuits to any interior walls being planned and effectively provides a level floor platform over a standard garage floor that can be sloped 4 to 5 inches from front to back.
Leveling out a garage floor can make it much easier to install any type of cabinetry or workbenches.
To insulate the floor of the room above the garage seal the space between the floor of the room and the ceiling of the garage and the top plate and the header joist with insulation.
First the floor may be so out of level that the garage floor does not meet the bottom edge of the door.
Nevertheless the concrete slab floor still remained really cold.
Second and far more critical is when the garage floor has begun to tilt backward toward the house.
This can be done through blown in insulation and unfaced or faced batt insulation.