Slabbing Out

This week's main job was to start the 'slabbing out' of the upstairs rooms. All the house's exterior walls except one will be lined inside with thermal insulated panels. These come in varying thicknesses for use in different situations but all (put simply) comprise a layer of dense hard foam stuck to a sheet of plaster board. There are other layers of membrane and metal foil but you get the picture - you stick them to the wall plaster-side out and skim-plaster them like you would any other wall. Your room is then up to 4 inches smaller in every direction but a whole lot warmer. We are using 4 inch thick on our outer (stone) walls, and then 3, 2 and 1 on various other bits.

Obviously these sheet bury the walls, so the walls have to be sorted out and made good first, and any cabling and water pipe run round (first fix) before you fit them. The walls are sorted out with cement if need be, or with PVA stabilizer (e.g. Unibond) if they are crumby-dusty. Next the walls get a slap of a pale blue gritty glue called Thistle Bond. Thistle Bond is a bit like Copydex in that it sticks to everything and everything sticks to it. It gives a good grip to the wall. You then mix up 'bonding agent', white powder and water, whisking it with a big whisk on an electric drill in a bucket till it is the consistency of whipped cream. You need to "splap" this onto the wall every 18 inches or so leaving a meringue-peak sticking out from the wall. Your insulated panel, cut to size and bevelled or mitred at the edges, then gets pushed, whacked and bullied down against the lumps of bonding till it is glued tight against the wall.

The bonding sets like plaster after a few hours. There are also special big headed 'nails' called anchors or mushrooms to help hold it in place if you need to. You do all your big flat walls first - the sheets are 4 foot by 8 foot, then you fill in all the gaps and do all the messing about round window reveals. Our walls are 50 cm thick so the reveals are nice and deep. Some people would just line these with wood or plaster board, but we are using thinner insulated panels. The panels are all copies of sheets invented and marketed as "King-Span", but these are made locally and branded Quinn-therm or Bally-therm. They are quite expensive. The 4 inch thick sheets for example, are €40 each, but the theory is they save their value in heat energy over the years.

Deefs