The old walls of the original cottage (lounge and one wall of kit/diner) are rubble filled traditionally built stone walls around 450mm thick. The mortar has the consistency and stability of mud - don't think much lime went into it. These walls were built on larger foundation stones directly onto the sandy soil. Moisture rises up from the ground and gets into the stone walls - this will create damp patches in any plaster we put on the them. If the stones were larger and more even, we could perhaps have used silicone injection damp prevention but they are too small for this and the wall contains too many voids.
Our way round this is to use a membrane that you attach to the walls. This will have vertical timber battens laid over the top and then plasterboarded. Now... any moisture in the stone may condense on the membrane and run down to the ground. This water has to go somewhere or it'll build up and eventualy create pools of water on the floor. Therefore, we've placed drains that run along each of the walls which lead to outside. Any condensates we get will hopefully simply drain away.
The membrane is fixed to the wall using 10mm plugs that have integral sticky rubber washers - these prevent water from behind the membrane coming through the hole you've made in it. The plugs have holes in them that later allow you to screw battens to the wall.
The theory of al this is fairly simple but in practice it's quite fiddly. All the plugs need to be in line at 600mm intervals. Finding stones that will take a 10mm hole is tricky. We've also got a lot of openings and several bits of wall that stick out into the room and a fireplace to tank around, which makes for a lot of folding and taping.
No comments:
Post a Comment