Ground Moisture Barrier
A ground moisture barrier is a legal requirement in all properties as per Healthy Homes Standards 2019. A ground moisture barrier protects against rising damp and mould, making homes drier, warmer and easier to heat. This ground vapour barrier is 250-micron thick polythene for maximum, lasting protection from cold and damp.Moisture under a house can cause mould and mildew inside the house, affecting the health of the occupants. Would you believe on average, 250ml of water can evaporate from 1m² of ground in 24 hours – that’s 60 litres per day on average for a 150m² house. A good way to reduce moisture levels is to install polythene sheeting that is at least 0.25 mm thick over the ground under a house. This vapour barrier will restrict the evaporation of moisture from the ground into the subfloor space.
Installing a vapour barrier (thick polythene sheeting) on the ground under your house will keep the moisture in the ground and stops the air under the floor from getting damp. For the vapour barrier to be .effective any leaks from water or waste pipes, wet areas, cladding and so on must be dealt with before the material is installed. We need to check there is no surface water flowing under the building and rain should drain away from the house. The vapour barrier is installed completely to cover the soil & be butted up to surrounding foundation walls and piles.