Why Cover The Concrete With Plastic Sheets

It can protect the new concrete from environmental cooling and heating fluctuations as it cures and it helps resist uneven curing due to rapid moisture loss at the top.

Why cover the concrete with plastic sheets.

Curing compounds are chemical products usually sprayed directly over the concrete surface and allowing it to dry. In cold weather plastic clad concrete curing blankets are often used to protect the surface from snow and insulate the concrete from freezing. A plastic polyethylene covering retains moisture in the concrete and improves temperature control. Adverse weather conditions such as rain snow or freezing temperatures often make it necessary to protect concrete by covering it.

A concrete vapor barrier is simply a sheet of polyethylene plastic visqueen placed directly on top of the sub grade before the concrete floor or slab is poured to help keep moisture from the soil from passing up through the concrete. If the temperature is below 60 f use dark colored plastic sheets to absorb more light and boost the temperature. The curing concrete with plastic sheeting after a short spell of water curing for one or two days is sometimes beneficial. One of the most effective materials to guard against rain is plastic sheeting visqueen.

The drying or curing should be gradual otherwise cracking may occur. When plastic sheeting is used over flat surfaces such as pavements or slabs it should extend beyond the edges of the slab by a length of at least twice the thickness of the slab. Plastic sheeting can permanently discolor concrete. Polyethylene sheeting under concrete slab under slab vapor retarders play a very important role in retarding moisture from coming up through the concrete and into the structure.

Water is mixed into concrete to activate the cement binding agent and as the mix dries it hardens. Today most experts feel very strongly that engineered films designed specifically for use as vapor retarders should be used as vapor retarders. For this reason concrete could be effectively covered with a plastic sheet so that it seals the evaporation of water from concrete. When temperatures are higher than 85 f reflective white colored sheets help to keep the concrete cool as it cures.

Covering the curing concrete with plastic keeps it cleaner but there is a more important purpose behind this practice. Curing concrete with plastic sheeting requires covering all exposed areas of the concrete as soon as possible without damaging the concrete finish. You may have seen fresh concrete covered with plastic while it is curing. Covering fresh concrete with a plastic sheet has other benefits besides protecting it from rain.