Interior wall insulation

Don't bother trying to bodge it. £400 is not unreasonable cost for cavity wall insulation in a bungalow. In my experience it is worth every penny. Because the roof area of a bungalow is much higher than a multi-story building it is even more worthwhile having the roof insulated to current standards. Try shopping around as it is a competitive marketplace.

Peter Crosland

You might even be able to get a grant if £400 is a serious financial outlay for you. Bob

Peter Crosland ( snipped-for-privacy@yahoo.co.uk) wibbled on Sunday 02 January 2011 21:51:

Agree. Even my bungalow with it's old blown fibre cavity wall insulation done a long time ago (I have seen it as I've been in parts of the cavity doing works) does actually seem to work very well.

Inner leaf of external walls holding up quite well even with -5C outside for prolonged periods.

Wish I could sort my roof (and I mean roof, not attic floor) out for only

In the 1970s you used to be able to get about 1mm expanded polystyrene rolls to paste to the wall before you papered, but IME (as occupier of the walls in question) it was useless. Nowadays that thickness would be a joke; but of course sleeping-mat thickness would cost a lot more.

How would it compare in cost to paper the walls in sleeping mats, more or less than 400 quid ? :)

Nick

That will save you 3 figures a year, go for it.

NT

No joke. Its about as good on a solid wall as adding a cavity.

More :-)

I agree with Tim's comments, and find the same with my own bungalow.

The alternative would be to batten the walls and fit 50mm Kingspan/ Celotex and plasterboard/skim or dry line, but that's really a method for solid walls.

The theory with cavity wall insulation, as I understand it, has to do with thermal mass. Your heat source heats up not just the air in the room, but the inner leaf of the wall, which, being insulated from the outside, retains heat and helps keep the building warmer.

Conversely, insulation added to the interior of a room will enable the air in the room to heat up more quickly, but there is no effect from thermal mass. So if someone opens a door to the outside, for example, all the heat can be lost quite quickly.

Cheers Richard

And the inner wall retains coolness in summer. And you need not redecorate. But are there electrical wires in the cavity? - they could overheat if insulated [g]

The quote was £150, which would have been fine. But because of the carport, they said scaffolding might cost £200 (maybe more), unless I dismantled it (and it looks pretty heavy).

There is also a loft conversion, but that doesn't have any exterior walls except for a bathroom against the gable wall. (And they didn't like my suggestion of filling from inside.)

And they mentioned something about a gas fire needing to be disconnected, because they couldn't guaranteed an adequate air supply with the walls filled; didn't quite get that.

The problem is, is that apart from the side of the house, the front and back have little wall area because of the large windows. (The kitchen wall is mostly door, window, and base unit; you can hardly see the wall, and that is the coldest room with it's stone-tiled floor; the whole downstairs has a concrete floor.)

But I think I will get that second quote though...

BartC ( snipped-for-privacy@freeuk.com) wibbled on Monday 03 January 2011 14:58:

If you are getting quotes, it is also worth asking what material they use to fill.

This could include:

Blown fibre - quite good IME and doesn't drop out (much) if making holes in the wall.

Loose polystyrene beads - the worst - come pouring out if you take a brick or three out.

Same but made sticky with some coating agent - supposed to be good.

Chemical foam - think they stopped using this (this was the stuff that caused headaches and was last used to my knowledge some decades ago).

Maybe others...

If they use polystyrene beads - you will want to be sure there are no PVC cables in the cavity, including meter tails as polystyrene and PVC in contact react badly to the detrement of the PVC.

Also Google insulation grants. Judging by the telephone calls that I get there are a lot of firms out there trying to get grant work. You might be able to get it done for free, I did.

A friend (living in a converted farm buildings with solid stone walls) has just done some of his external walls with Superquilt.

In an email, he says: "The problem with that room is that it has 3 external walls - 22 square metres of stone wall. Superquilt is supposed to have the equivalent insulation properties of 10" of mineral wool. Since we have finished the lining the room has been really cosy and our underfloor heating system has had no problem in keeping the room at the thermostat setting. Before it could not provide sufficient heat input to maintain temperature so I am happy that the DIY job is proving to be a success. I now have to fit the plasterboard and apply a skim of plaster prior to decorating."

At the end of the day (as they say in these parts), putting insulation over a solid wall is what you do when you don't have a cavity that you can put the insulation into. =A3400 quid sounds like a reasonable price for the OP to do the latter, which should result in a noticeably toastier bungalow. If it's like my bungalow and has big windows, then if these aren't double glazed already I'd budget for that too.

Cheers Richard

Update: I've just had a second quote of £199.

The car port roof was deemed strong enough to work on, but they are happy to work from inside too if necessary.

And the gas fire was only 6kW, so does not need disconnecting.