foam spray insulation

ranngela · 23 Jan 2009

My loft space is in a poor state due to lack of roof felt - I have the original paper which is coming away in places and I can see daylight. All is reasonable dry up there but is difficult to keep house warm.

As far as I see it there are two options open to me:

remove all tiles and re-felt and replace same tiles

or seal with spray foam which would provide some insulation at the same time.

For both options I need scafolding to undertake other repairs to hip tiles

not sure which to go for...anyone had the same problem with roofing felt?

noseall · 23 Jan 2009

ranngela said:
As far as I see it there are two options open to me:

remove all tiles and re-felt and replace same tiles

or seal with spray foam which would provide some insulation at the same time.

yes, to first option

noooooooooooooooo! to second option.

SurreyRoofingEstimator · 23 Jan 2009

Echos's Noseall's comments.

cjard · 23 Jan 2009

What insulation do you have on the floor of the loft space? (i.e. touching the ceiling plasterboards)

ranngela · 24 Jan 2009

no insulation at allat the moment - is it not possible to waterproof the roof space without takin goff the tiles - why a big noooooooooo to foam spray?

noseall · 24 Jan 2009

ranngela said:
no insulation at allat the moment - is it not possible to waterproof the roof space without takin goff the tiles - why a big noooooooooo to foam spray?

shocking stuff, typical quick fix rubbish.

ruins the roof, full stop.

cjard · 24 Jan 2009

ranngela said:
no insulation at allat the moment - is it not possible to waterproof the roof space without takin goff the tiles - why a big noooooooooo to foam spray?

If the roof space itself isn't wet i.e. the tiles arent leaking, then I'd be less concerned about replacing them.. Tiles keep the water out, not felt. Felt wasnt used at all until relatively recently. Why do you ask "is it not possible to waterproof the roof space" in the same breath as "the loft is all relatively dry" - either your roof is leaking or it isnt. If it isnt, then leave it alone!

Most of your ehat goes out of your roof because you have no insulation at all. Minimum requirements nowadays are 250mm. From what you've said, you'd be better off insulating your loft correctly and leaving the tiles alone until they definitely need work doing. It isnt logical to insulate the tiles, and thus have a big empty space in the loft that you heat, but do not use.. You should have a cold loft and a warm house

ranngela · 24 Jan 2009

Thanks, that sounds particularly sensible - I will have a good check for leaks/dampness...

chappers · 24 Jan 2009

run a mile from sprayfoam. if your roof is in a poor state and leaking then the sparay foam will just trap the moisture and your roof timbers will rot, likewise if a leak develops in the future.
Also if you ever need to repair or replace any tiles/ slates in the future you will have one hell of a job as the spray foam will glue the lot together and you will end up tearing half the roof off to replace one or two tiles.
seeing abit of daylight through your roof tiles is not a problem unless it is leaking.
As has been said could you not insulate over the ceiling.

colin2009 · 25 Jan 2009

foam's rubbish and will be pulled up on a survey re-roof and insulate it
DO THE JOB RIGHT LOL

price about £30 a square metre

taff21 · 29 Jan 2010

i had foam sprayed on my roof tiles in may 2005, dec 2009 roof timber rotten. Dec 2009/jan 2010 new roof fitted.
I had a dry healthy roof prior to being sprayed, the firm (re******m)quoted that their foam was breathable, waterproof etc. Their 25 year guarantee only covers their foam and not damage to the roof. DEc 2009 the firm went insolvent, but they are still advertising on internet, their association backup insurance only covers the original guarantee.

freddiemercurystwin · 29 Jan 2010

taff21 said:
the firm (re******m)quoted that their foam was breathable

And you believed them?

alittlerespect · 29 Jan 2010

Hi

Possibly for best results use a 50mm thick PIR insulation board and cut to a tight fit between rafters, finishing off flush with the face of the rafters - this will/should give a gap between the insulation and the roof covering which will allow the roof to breathe and dry out when condensation forms on the underside of the slates.

Use a further 50mm thick PIR insulation board over the whole of the internal roof ,fixing the insulation to rafters etc. fit with staggered joints then for a bulk basic job leave as is, if you want a slightly better finish finish tape all board joints and perimeter edges (duck tape would do) - then if your not fussed about the finish either leave alone or paint it to brighten the area. PIR insulation is very vapour resistant and you do not need a vapour check barrier - job done!

It has been mentioned in other threads that it is possible to buy second hand PIR insulation off ebay, but I have never tried this approach so I cannot make further comment.

Regards

diynot

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foam spray insulation

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