Cavity wall insulation - and now the roof . ..

[Stephen]

Many thanks for all of the replies - now off to sort out getting the wall insulation done. Whilst I'm on the subject it would seem a good time to take a look at the roof too. At the moment it is lagged (between the ceiling joists) with 100mm fibreglass stuff. It seems that todays fashion would indicate more depth. Or would I be better to add insulation between the roof purlins under the tiles ? The roof is a 1980s W wooden frame holding up tiles, with felting underneath. How I'm going to crawl into the farthest reaches of the roof space I don't know ! I presume I should leave the small gaps under the eaves open. What do you think ?

[Rick]

I had a similar thing, I put 250mm more in, going accross the joists.

I simply dressed up, covering every tiny bit of skin and crawled in. I used a couple of boards to make sure I did not go through the ceilings.

If you insulate between the rafters, you will still have an air gap where the eves are open.

Rick

[Dave Fawthrop]

| On Wed, 16 Nov 2005 23:14:11 +0000, Stephen | wrote: | | >Many thanks for all of the replies - now off to sort out getting the | >wall insulation done. | >Whilst I'm on the subject it would seem a good time to take a look at | >the roof too. At the moment it is lagged (between the ceiling joists) | >with 100mm fibreglass stuff. It seems that todays fashion would indicate | >more depth. Or would I be better to add insulation between the roof | >purlins under the tiles ? | >The roof is a 1980s W wooden frame holding up tiles, with felting | >underneath. How I'm going to crawl into the farthest reaches of the roof | >space I don't know ! | >I presume I should leave the small gaps under the eaves open. | >What do you think ? | | I had a similar thing, I put 250mm more in, going accross the joists. | | I simply dressed up, covering every tiny bit of skin and crawled in. I | used a couple of boards to make sure I did not go through the | ceilings. | | If you insulate between the rafters, you will still have an air gap | where the eves are open.

Eaves should always be open to ventilate the roof space.

I used a long stick/broom to push the insulation to the end of the joists. I saw some insulation in B&Q which was covered with polythene, which might get over the itching problem, not sure about costs.

[Rick]

Its not much better, and lots more cash. The cheepest is normally wickes, but they will run out this wekend - so go early.

Rick

[chris French]

In message , Rick writes

That depends. I'm really sensitive to the fibres in glassfibre and Rockwool insulation. I installed some as extra insulation in my old house and for me it was much more pleasant to handle. I also found it a fair bit easier to install over the old insulation, presumably because the plastic /foil slips easier over the old stuff.

[<me9]

I'm tempted to try celotex/kingspan from secondsandco as it's thinner for a given performance, and I haven't much room, as it's a low pitched roof. I couldn't do it with GF or RW cos of the irritation, and I want to use the minimum thickness below the boarding in the loft. I currently have 50mm fibreglass between nominal 100mm (90 actual) joists.