Damp Proofing Mesh Membrane 2m x 20m (40m²)
(Insulation Plaster Plug Fixings are not included in this listing, please order your Insulation Plaster Plug Fixings here if required)
Damp Proofing Mesh Membrane with 2.5mm profile stud ideal for rendering after the installation of a chemical DPC or areas of damp such as chimney breasts.
The membrane made for HDPE material is impervious to salts and vapour and waterproof. The 2.5mm stud allows a wall to breathe behind the membrane. Suitable for a dot and dab plasterboard finish or you can render directly to it.
When applying Damp Proofing Mesh Membrane you fix the membrane to walls with Insulation Plaster Plug Fixings.
Membrane should be applied tight to the wall with no ‘bubbles’ or kinks. For a dot and dab plasterboard finish fixings should be applied at 250mm centres. For a render finish and to avoid cracks in the render, centres should be reduced to 200mm centres.
Render with a mix of sand, cement and lime should be applied in two coats using the procedures defined within BS EN 13914-1:2005 to a total thickness of 14 mm. A 3 mm skim coat of finishing plaster can be added once the render is fully cured. The scratch coat should be a mix of 1 part lime: 1 part cement: and 5 parts clean well-graded sharp sand. The second or float coat should be a mix of 1 part lime: 1 part cement: and 6 parts clean well-graded sharp sand. The scratch coat should be 7 mm and the second or float coat should be 7 mm.
To lessen incidents of cracking, it is best to mix the lime and sand a day or more before use. Cement can then be added at the time of rendering. The work should be of two coats of render and if required, a third coat of finishing plaster. The purpose of the 7 mm scratch coat is to stiffen up the lath and to provide rough and absorbent backing for subsequent coats.
Work this scratch coat well into the mesh. Each 7 mm coat of render should be allowed to dry for a period of not less than 7, preferably 10 days, longer if possible. Cracking may occur if shorter time is allowed between coats. It is important that the render coats are allowed to cure correctly over the 7 to 10 day period with the render dampened as required. If the scratch coat has not fully cured, slumping of the render can result. Before applying the second or float coat, carefully drill or scratch out a small section into an area behind the mesh, within the membrane stud, to
confirm that it is fully cured. The surface will cure quite quickly but the area behind the mesh must be fully cured also. In warm periods the render should be protected from excessive drying out by covering with damp hessian sheets and plastic sheeting over it. Dampen down the scratch coat before application of the float coat.
Plaster board panels can be fixed to the membrane with the dot and dab method, giving a dry surface ready for immediate decoration. ‘Dabs’ should be applied to the heads of the Fixing Plugs,
board edges and membrane to cover 50% of the membrane.
NOTE: We do not recommend that laminated or insulated plasterboard is dot and dabbed to meshed membranes. Laminated boards have to be fixed to the wall with a mechanical fixing at each side of the board, just above half way.
To avoid the passage of vapour or moisture to travel through the entry point of a plug fixing in the membrane it is advised plugs have a neoprene washer seal on them. Areas that are higher up a wall and not prone to damp my not necessarily require a seal but we do recommend their use.
Roll dimensions: 2mtrs wide x 20mtrs long x 2.5mm stud height