The external wall insulation works are being carried out by Pegasus Externals Ltd from Bradford, an approved installer of JUB systems.
The insulation is 280mm thick graphite EPS (expanded polystyrene) made by S and B EPS Ltd in Northumberland. Lambda value is 0.032 W/mK. The boards are fixed by a continuous bed of adhesive (rendered on to the brickwork and thereby forming the air-tight line) and then mechanically restrained with EJOT STR U 2G anchors, 335mm long.
Countersinking and plugging the heads halves the chi value (point thermal transmittance) from 0.002 W/K to 0.001 W/K, which doesn't sound a lot, but adds up when there are five fixings per board.
Been busy the last few days, taping in preparation for the external wall insulation crew. Now it's a race to stay ahead of them as they chase me round the house.
We are primarily using ProClima Contega Solido Exo tape (black) as the fine fleece facing is suitable to be rendered over. Also Tescon Vana (blue) where not being rendered. The insulation boards are adhered with a continuous spread of adhesive (like render) that effectively becomes the parge coat, and then mechanically fixed.
Solido Exo is more flexible and forgiving than Vana, but both are super sticky, especially with Tescon Primer on the fairly rough brickwork.
Thinking of buying shares in ProClima.
Preparations are well under way for the external wall insulation to start next week. The scaffold is back up after 6 months away and the 'garden' is full of graphite EPS insulation. The perimeter XPS down to footing level is complete (not the easiest dig ever).
Job for the sunny weekend is to tape between brickwork and window frames, and between brick and XPS insulation. There's another air-test planned for week after next and there's work to do to improve the air leakage rate.
Russel and Anna Hayden