Remove any protrusions from the surface e.g. nails or screws. Ensure walls are suitably sound for drilling and holding plugs: repair if necessary. Remove any wallpaper. Walls and ceilings that are liable to crumble or shed excessive dust which would build up behind the membrane should be treated with a surface hardener, such as
. Floors should be swept clear of any sharp debris which could damage the membrane.
Walls
Walls should be lined before floors, as the floor membrane may need to overlap the wall membrane. Apply the membrane to walls in vertical strips, blisters to the wall. Cut the required length for the first piece and hold in position at the selected starting point. Ideally work from left to right across each wall, hanging each piece with the 65mm wide flat flange on the left. As an aid, temporarily secure near the top centre to create a ‘pivot’ point and vertically align the membrane with a spirit level and/or a plumb line.
For the best seal, we recommend fixing holes are drilled through the round blisters, rather than the raised surface. Bearing in mind the position of fixing centres for positioning timber battens, drill two 10mm holes to a minimum depth of 80mm through the membrane into the substrate as near to the top of the membrane as possible. Fix by tapping Brick Plugs (see
datasheet) into the holes using a club/lump hammer without excessive force. This will allow the membrane to hang. Before fixing each Brick Plug the hole in the membrane should be cleaned of debris to ensure a good seal. We recommend the membrane and wall should be drilled and plugged approximately every 250mm to fix the strips in place, with an absolute minimum of 5 plugs per m².
Vertical Joints
One edge of each reel is flat, the opposite edge has a tape channel. These are used to create an overlapping vertical joint (a flange seam) between one strip and the next. Clean both edges with a dry cloth and we recommend the membrane is heated slightly with a warm air gun. Apply double sided tape to the tape channel, overlap with the next piece of membrane and seal with firm pressure along the top surface of the flange. In some circumstances it is advisable to apply 75mm wide overseal tape over the flange seal. Where vertical joints need to be made and it is not possible to use the flattened edges, the two sheets of membrane can be joined by a butt joint, sealed with 200mm wide oversealing tape. Ensure the two edges to be sealed have been cut straight.
Below ground or in particularly difficult situations the two sheets should overlap by 250mm and be sealed with 200mm wide overseal tape. The same 250mm overlap should be used if you need to make a horizontal joint across a wall: the top membrane should go behind the bottom membrane so that any moisture running down the wall/ membrane gap cannot leak into the room. After fixing the membrane to walls, timber battens to carry a dry lining can be fixed to the plugs using No. 12 screws.
Floors
Simply lay the membrane on the floor, dimpled side down – no fixing is required. Edges of adjacent strips should be butted up to one another and 200mm wide Overseal Tape applied over the top of the joint (see
datasheet). Above ground level the edges of the floor membrane can be butted up to the wall membrane and sealed with 200mm wide tape. Below ground, edges and corners of the floor membrane should be folded and lapped up the wall by 250mm, then fixed over the wall membrane with 200mm overseal tape. After lying, the membrane can be screeded with a dry sand/cement or concrete mix (min 75mm thickness), or covered with a floating floor (e.g. wooden laminate).
Sealing tapes
Before using all tapes it is recommended that a warm air gun is used to warm the membrane surface, or the tape/sealant, as this will greatly enhance the adhesion. Always ensure surfaces are dry and clean before applying any tapes or sealants.
Pipes, cables and other services
Services penetrating the membrane should be sealed using 200mm Overseal Tape in a ‘collar’ fashion. Cut a piece of 200mm Overseal Tape at least 4 times the cross sectional area of the incoming pipe. Draw in the centre of the paper side an exact profile of the pipe to be accommodated. Within the drawn profile area cut diagonally to at least four points then make a single cut to the nearest edge to form a ‘collar’. Remove the protective backing paper then position and press the sticky face of the Tape against the membrane around the pipe. Wrap another 50mm wide strip of Overseal Tape over the profile cuts around the pipe, immediately adjacent to the collar. Apply a third, narrow strip of Overseal Tape around the joint.
