No Vapor Barrier In Garage Floor

Writing to ask if i should using a kraft paper barrier plastic vapor barrier or no vapor in my garage insulation project.

No vapor barrier in garage floor. Allow 48 72 hours and evaluate. The garage was built in 1922 slab on grade and no underslab vapor barrier is assumed. Vapour barrier is on the top of the rafter then insul then board if heating garage insul vapour then board need hatch for summer to let out hot air i m a insulator typar is a better product in a. This vapor barrier is nothing more than a heavy plastic sheet.

Lay vapor barrier. Such a location works both as a vapor barrier as well as an air barrier and eliminates the need for an external air barrier not a easy application on a multi storried building as well as any special electrical pans and their sealing. I am starting the process of insulating my detached 23 x 32 garage in buffalo ny cold lots of snow winters with the secondary goal of having constant natural gas overhead heat keeping. A good test for ground moisture in slabs is to duct tape several 4 x4 squares across the surface of the floor in different locations.

There is little you can do to correct this problem other than removing the existing slab and pouring a new one with a vapor barrier under it or put a vapor barrier on top of the existing slab and. Insulating concrete garage floors begins with covering the entire floor with 6 mil polyethylene which will serve as a vapor barrier. Some slabs are laid down with plastic material under them but older structures may not. Vapor barriers the pre construction solution is to use a vapor barrier under the concrete.

Vapor barriers are a way to keep moisture from getting into the concrete. Overlap the seams about 6 to 8 inches and seal the seams with waterproof construction tape. Vapor barriers have varying degrees of permeability expressed in perms. Unfortunately contractors or owners often discover that no vapor barrier was used or that the vapor barrier has probably been torn or damaged possibly when the concrete was poured.

Condensation under the plastic indicates moisture due to no vapor barrier. I install my vapor barrier in the middle of the wall system between the two walls. Do not apply a sealer or floor paint to a garage floor that doesn t have a vapor barrier since the finish will not adhere well to the surface. However if you live in a cold climate zone such as alaska it s a good idea to install a vapor barrier on the warm in winter side of the wall.

Most garages don t need vapor barriers because the amount of vapor that diffuses through garage walls ceilings and the floor is not enough to cause wet walls that result in moisture damages. However there are underlayments that act as vapor barriers.