Cavity Wall Insulation

Cavity wall insulation should only be approached when you are sure your cavities are clear of any debris and there is no signs at all of damp on your internal walls. The cavities become 'bridged' due to mortar 'snots' (pieces of cement which loosen over time on the inside of the cavity walls. If these build up higher than your damp course level you must have them clean before any insulation is pumped into them. I work with lads who do conventional damp proofing (a plastic membrane is placed on the damp course level and removed bricks are then replaced. This guarantees no damp penetration and once you have this you can then confidently go for cavity insulation. However, I advise against cavity wall 'injection', this is a complete rip off if you live in a house built with stock brick. Stock brick is non-porous and therefore will not soak up any of the injection. Rant over.

 

I had that in my last place, ended up taking the roof off to get to the bit where the ceiling sloped.

 

The curve in your ceiling is likely to be made from the old lat and plaster method, you may be lucky and its only plasterboard. Either way you will not be able to stuff insulation in there successfully without taking that part of your ceiling down. In older houses this is a messy job, but it seems to me the only way to help your problem. Strip the curve back to the ceiling joists. Buy enough silver-foil backed plaster board to re-board your ceiling. Place insulation into the void as you re-board, making sure the foil side is facing the loft space. Re-plaster. It's messy,but it works.

 

Great!
a neighour who had the same problem after having their loft insulated some years ago, managed to do this from inside their loft, and it solved the problem, so hopefully, so can we.

 

Actually, i have a mains extractor in my bathroom, and it is only since the wall insulation was installed that i have noticed this damp - which we have immediately blamed the loft insulation, because it is in the curve of the ceiling i wonder if they could've blocked the fan outlet with the wall insulation? Something else to try. We'll get to the bottom of it somehow!

 

Undo the four screws that hold the extractor fan in place, then gently ease it forward. No need to do anything with its wires cos the goal is just to see behind it. It should then be immediately obvious if the outlet is blocked or not because you'll be able to just see.

 

EDIT: I should have said, turn the mains power off at the main switch before looking behind the extractor fan. The wires should all be nicely secured but you just never take chances with mains electricity.

 

Pixie? Pixie? Speak to us

 

Do not stand in a bath of water when disconnecting a fan connected to the mains :-)

Jack McH

 

Randle & Hopkirk 1969.

Looks like Pixie has gone on now



Two minutes silence for a lost member

 

Pixie's still alive everyone

 

Just seen her out and about - feeding the garden birds,

 

We had it done last year by Eon and had to pay £99 then (but still good value for a 4 bedroom detached house), our house is only 23 years old and is fully detached, but the inner breeze block had a polystyrene filling for the insulation but nothing in the cavity.....I can honestly say that its had a big effect, last winter we noticed that after a cold night it was not that cold inside when you woke up in the morning (we don't have the heating on during the night). Also the house says warmer for longer after the heating has been switched off.

Also with Eon they have a energy tracker and I feed in the meter readings each month and last winter our gas usage was about 7% lower then the year before (this was even allowing for the fact that we had a new condensing boiler fitted the year before the cavity wall insulation)

But the biggest cost / energy saving was the new boiler, our old boiler was some 20 years old (cast iron job) and costing a fortune to run, since we had the new Condensing Boiler fitted our gas usage has gone down by some 20% and with the cavity wall insulation, its more like 27% because our heating is on for a shorter period as the house stays warmer for longer