Ask NSC: Wall insultation

I've recently moved into a house that was built in around 1992. We've had some work done on the fireplace which gave me a chance to see the wall cavity. I've attached a photo below, which shows that a sheet of polystyrene has been used, the sheet fills about 1/3 of the gap. So I have two questions:
a) Would additional insulation be a benefit?
b) If yes, then would we possibly qualify for one of the free schemes given that there is some insulation there already.

Bad Ash said:

I've recently moved into a house that was built in around 1992. We've had some work done on the fireplace which gave me a chance to see the wall cavity. I've attached a photo below, which shows that a sheet of polystyrene has been used, the sheet fills about 1/3 of the gap. So I have two questions:
a) Would additional insulation be a benefit?
b) If yes, then would we possibly qualify for one of the free schemes given that there is some insulation there already.

Click to expand...

Be very cautious about full fill blown cavity insulation. That looks a narrow cavity and I can already see mortar snots on wall ties and large mortar lumps squeezed out of the joints not cleared by the bricklayer as they went. As a narrow cavity the risk would be full fill insulation creating a situation where moisture can bridge the cavity. This happens quite a lot, and as debris and dust over time fall down the cavity, in the places it collects it can make the insulation damp, and the moisture will bridge across. The external brickwork pointing or render also needs to be in excellent condition so that water cannot penetrate into the cavity. Brickwork is porous but it is a slow process and generally the cavity copes with not letting it through. However with any defects and water effectively pours in through capillary streams, the full fill insulation as said above can start to get too wet and you get a bridge to the inner leaf.

If the house is rendered, then you can get a grant for external insulation that is rendered using an acrylic render system, or you could consider an internal insulated composite plasterboard but obviously you lose a bit of space off the room.

There are plenty of articles about this, but I wouldn't report your cavity as appearing 'clean'.

http://www.yougen.co.uk/blog-entry/1796/Does+cavity+wall+insulation+cause+damp+'26+condensation'3F/

im not sure, but iirc those insultation schemes were only "free" for pensioners and a few other groups. otherwise its a subsidy.

I saw a drunk guy insulting a wall at about 5 in the afternoon last Sunday.

Call yourself a wall? You're no more than a very ugly pile of bricks, you useless bast@@d.

Will that do? Or were you thinking of the full 10 minute, effing & jeffing style insultation?

Thanks for the info Bold, I didn't realise it was such a minefield.

Looks like those wall insults might come in useful! ;-)

Not sure how many are still around but the energy companies all had targets for improving energy efficiency so offered discounted schemes for cavity walls and loft insulation. We had ours done by Tesco a couple of years ago (even though we are not a Tesco Energy customer) and I think it was £99 for the loft and £99 for the walls back then - pretty good value for money.

If you look on MoneySavingExpert they will probably still list anyone still offering such schemes.