Roof insulation: Cold call from firm that sprays closed-cell foam between roof rafters.

[Al-W]

G'day!

Today, I had a cold sales call from a company offering to spray closed-cell (polyurethane?) foam between my roof rafters. I thought I'd run this past you folks, because a lot of you understand this sort of thing.

I didn't take up their offer of a free assessment for various reasons, but some of the things the salesman claimed aroused my curiosity.

1) He claimed that the UK Govt is subsidising such work, and that if you ar e retired, you qualify for the maximum subsidy. I was under the impression that grants for insulation ended some while back. Can anyone confirm/refute this?

2) He claimed that I would save 40% on my heating bills. I expressed skepti cism, pointing out that I had a very drafty loft, and therefore doubted if insulating the roof would make much difference. I dare say someone might sa ve 40% if their loft was draft-proof and they had no standard loft insulati on already in place. Anyone agree?

3) Another thing that made me hesitate, is that I've thought about this for m of roof insulation before. It has occurred to me that spraying plastic fo am around roof timbers might not be a great idea, because roof timbers need air circulation to prevent hazards such as rot and woodwork. Anyone agree?

4) The salesman also claimed that the Govt is going to outlaw glass fibre l oft insulation because it has been discovered that it's inefficient. This s ounded like nonsense to me. Anyone agree?

I'd appreciate your thoughts and insights on this.

Al

[Tim Watts]

Spraying foam would probably draught proof it. It will probably also cause untold amounts of rot as I bet they won't reroof your house to install breathable membrane and suitable ventilation.

Utter complete bollocks. That really tells you everything you need to know.

[newshound]

I think you have covered the bases pretty well. My personal rule is

*never* to trust cold callers.

Other thoughts, is your roof felted? And how good is the felt? Slate or tiles? If they didn't ask about that, be even more suspicious.

[Chris J Dixon]

There seems to be an endless supply of folk with such snake oil schemes.

Another wheeze is to spray some form of thin external coating on the roof tiles with the claim that it could save "up to 30% of your energy costs. I reported one outfit to the ASA, but they said that because of the "up to" they would take no action. :-(

Others now try to convince me that because my double glazing is over 10 years old, then I should replace it with the very latest magic panes.

Looking at round numbers, my gas costs my about £500 a year. Lets say that about 75% of that goes on heating, and maybe 10% of that energy is lost through the windows, so that leaves us with less than £40 per year. Even if the new windows eliminated all energy loss, I can't see it paying back in my lifetime.

Chris

[DICEGEORGE]

re: [offering to spray closed-cell (polyurethane?) foam between my roof rafters.]

The roof 'draughts' I call ventilation, and are needed to dry out condensation etc up there.

This summer I'm finishing taking all the slates off my roof, replacing battens and Tyvek, and putting them back on. If they were sprayed with foam this wouldbe impossible and all the slates or tiles would have to be thrown away.

George

[John Rumm]

Standard sales pitch kind of stuff. Start by quoting a silly price, then reduce it as a result of the "grants" you are entitled to, to get down to a still silly price. There are some grants available for some insulation jobs. More readily available to the over 70's

Its doubtful that you lose 40% of your heat through the roof in the first place. So even if it reduced losses to nil, that sounds unlikely.

Its an ideal way of sealing in any trapped moisture against the wood and accelerating rot and decay. It also may bond the tiles into the whole lot and make it impossible to remove and reuse any of those.

Sounds like nonsense to me as well.

[Brian Gaff]

Well define inefficient really. Everything is relative. I'd outlaw it due to its tendency to make you itch when you go anywhere near it. No I'd not have any stuff like foam sprayed, if there is any damp there it will just make it worse. Of course that is my opinion. Brian

[Brian Gaff]

Yes never ever buy from a cold caller, at least before you look up other companies, what they say and what they charge.

My roof is extremely draughty as you could see out between the tiles. I've had numerous suggestions about insulation of this inner side, but to me many people suggest that a good air circulation is needed. So when they have flogged you the rafter insulation they will see the draughty loft and suggest the whole roof is insulated as well.

Brian

[dennis]

AFAIK the only grants for loft insulation will cover 100% of the cost of putting 300mm of glass or mineral wool in.

You don't need to be old or disabled to qualify either, sometimes just the postcode sets availability.

BG are frequently looking for houses to do to fullfill their obligation, you do not have to be a customer. 8-)

[Mike Clarke]

The general consensus is that, all other things being equal, about 25% of your heat is lost through your roof. It must be magic stuff if it can stop *all* that plus 15% more.

I suppose it's possible that it might reduce the heat loss through the roof by 40%, i.e. a reduction of 0.4 x 0.25 = 10% of your total losses.

He's either a liar or has no understanding of heat losses - either way not to be trusted.

[Al-W]

It's felted. To be fair to them, they wanted to send their surveyor over feist to look at the roof before attempting to sign me up.

Al

[Al-W]

The draughts are mostly coming from the venting in the soffit boards, which I guess are there for a good reason (other than increasing my heating bills). So I've always assumed it's best to leave the draughtiness as is.

Al-W

[Al-W]

Yes, that was my impression too, and was partly why I declined to have their boys come over to look at my roof.

Al-W

[Al-W]

Thanks. My roof has concrete tiles and it is felted (built in 1990). The felt is okay, although there's a patch missing in one place.

No he didn't ask. But to be fair, he wanted to send the company surveyor over to scope out the roof first.

Al

[DJC]

My house has this form of insulation, installed by the previous owners because they were probably too skint (negative equity I suspect) to repair the roof properly maybe 20 years ago.

1. As the tiles are effectively glued on, it will be expensive and difficult to repair the various broken tiles that are now evident.
2. That also preclude reusing existing good tile when replacing the roof.
3. There is no ventilation of the roof timbers between tiles and foam so there is a risk of rot developing.
4. There is less ventilation in the loft area so a risk of condensation.
5. It is a high pitched roof, hence a lot of attic space that is wasting heat that could have been prevented from escaping to the attic by insulation below. So it will mean a new roof just as soon as i get the right tuits.

[Mike Clarke]

And what's the betting that the so called surveyor would say that your house was perfectly suited for this treatment and apply high pressure sales techniques to try to get you to sign up before he left the premises,