Thursday, January 15, 2009

Keeping warm

I started off the year by having cavity wall insulation done on my house. Here in the UK (well England, anyway) the Government pays grants to the over 70s so they can get it done free. The money goes to the company who does it, not direct to the customer. You can also get loft insulation done too, including having it topped up if it does not reach today's recommended level.

I was having the bonded bead system, which "utilises two basic components, a specially manufactured grade of closed cell polystyrene FRA thermal bead, which is coated with an air drying adhesive during the injection process". When the cavity is completely filled, the adhesive sets into a homogeneous mass, which means that if you later decide to have your windows replaced, the little tiny beads - (only 2-5 mm in diameter) -will not come cascading out of the cavity! It's hard to believe, but the whole of that van is filled with beads, apart from the shallow area at the back containing the ladders, the generator, the drill, the container of adhesive, the hoses, a bag of mortar, a bucket etc.

Holes are drilled at regular intervals of about two feet in three or four rows in the side of the house. I had been warned that there would be considerable vibration, and that I should remove pictures and ornaments from at least the external walls. I expected to find the noise very intrusive but it really was not. The holes are drilled at the junction of three bricks where it is mostly mortar, and very little actual brick is lost. As you can see they are pretty neat.


For a semi detached house, unless the neighbour is being done at the same time, which is a good idea if you can arrange it, some sort of barrier has to be inserted between the two houses. This is done with a continuous length of flexible bottlebrush (blue in the picture). I missed the fun bit here, but it had been attached to a chain which had somehow been drawn into one hole and out through another, and was supposed to drag the brush after it. However, the chain had jammed, possibly on a metal wall tie, and would not pull through. Ithad to be cut and left in the wall, to act as a barrier in place of the brush. "Does this happen often?" I asked. He pulled a wry face and said "Ooh yes! Pretty often!"

Then comes the filling and the plugging, which is done as a combine operation. The hose is stuck in a hole, and loads the beads and the adhesive, which have mixed together in the nozzle. The hose is then placed in the next hole - (NOT left on the ground, where an accidental kick may move the release lever and cause sticky beads to cascade all over your garden!) - and the hole which has just been filled is plugged with previously mixed matching mortar, which is what you see in the next picture.

The job was done and dusted - well not entirely dusted, as there was a good deal of brick dust still lying at the bottom of my walls - but it was done in two and a half hours. It would probably have taken less if I hadn't asked so many questions, and if he hadn't told me about his dogs, and the special conservatory he has built for their comfort. He had two cups of coffee too, and rolled himself a fag to smoke with these. But that's the way I like to have a job done for me.


G in Berlin said...

THat looks really great! Before I left the States I tried to find companies to do exactly that but wasn't able to do so: not enough profit, I guess. In this housing depression I expect that when we go back it will be easier to find companies to help make older houses more efficient.
Tell us whether you notice a real difference: do you know what the R-value change is?
(And welcome back, Happy New Year).

Lee said...

Money well spent, I reckon.