Concrete Slab Vapor Barrier Repair

For most commercial applications the 15 mil thick concrete vapor barrier will be a better choice.

Concrete slab vapor barrier repair.

The concrete slab is then poured on top of it. Some supports come with wide bearing pads. The number of primer barrier layers is based on the amount of moisture present in concrete. Seams should overlap 6 inches.

Architects engineers and contractors therefore often disagree on whether concrete should be placed directly on the vapor barrier or on a granular base placed over the vapor barrier. Vapor barriers have been associated with certain concrete slab on grade problems including curling and cracking. Seal all vapor barrier seams with the tape provided by the barrier manufacturer. It successfully alleviates the problems associated with moisture accumulation in a concrete slab keeping moisture from reaching the epoxy flooring system.

Studies have shown that vapor barriers can affect the behavior of the concrete slab and significantly influence finishing time cracking and strength. The moisture vapor barrier helps reduce the passage of fluids through concrete. But they have also proven to be beneficial in reducing failures of moisture sensitive flooring materials adhesives and coatings caused by excessive emission of moisture vapor from concrete slabs. Water below the concrete slab can diffuse through the slab as vapor then condense under the flooring which can emulsify some adhesive and destroy the floor covering.

Do not pound form stakes through the vapor barrier. However the current practice recommended by the american concrete institute is to apply a heavy grade non penetrable vapor barrier or retarder with the lowest possible permeance for the application over a layer of granular fill crushed rock gravel etc. Water vapor diffusing through the concrete slab can also lead to deformation and discoloration of the floor covering material leading to costly repairs or even replacement. To minimize cracking on top of vapor barriers use a 100 mm thick 4 in layer of slightly damp compactible drainable fill choked off with fine grade material.

For most residential applications the 10 mil under slab vapor barrier will offer enough protection against moisture vapor transmission coming up through the concrete floor allowing for flooring materials to be successfully installed on top of the concrete. If you want to make sure your slab on ground gets dry and stays dry use a vapor barrier. Cure with waterproof sheets rather than with water or curing compounds. Choosing a vapor barrier.

All vapor barriers should conform to astm e 1745.