Roof – Foam torching

[Sam W]

Calling on the maillardvillemanor collective wisdom.

We’re nearing completion on the purchase of a lovely old Victorian house. It’s an old station, and as is typical of Victorian infrastructure, was built to last. Worth adding that it is also Grade II listed.

Going through the normal checks on the house before signing contracts, and we’ve found that at some point the interior of the roof (tiles) have been sprayed with foam. Everything I’ve read about foam torching is bad, but anything to add to the items below?

Cons

Replacing the roof is going to be even more expensive because pretty much every tile is going to break as it’s pulled off. 50% increase in the cost of the job? Plus problems with listed building people because we’ll have to find a good match on the tiles.
Some evidence that it increases the chance of water getting trapped, leading to rotten timber

Pros

The roof is currently in good condition, no tiles missing and timbers all appear solid. The foam will be a pain if we ever do need to replace it, but in the meantime at least the tiles are glued in place.

Any experience of this stuff or this situation? Walking away would be a painful decision, but is an option. We have a good relationship with the seller, and are paying a price that reflects condition (we knew general work was required), not sure how much further room there is for negotiation.

[FUZZY]

Friend of mine has this in their house. At some point you have to replace the whole roof – tiles and everything. So it’s a cost you’ll face at some point – or have to deal with when you sell the house. So you may as well factor it in now. If it’s prohibitively expensive to do it now, it won’t be any different in the future.

[nab]

Mmm, difficult situation to be in, especially as you seem to like the (rest of) the house.

As you stated, there’s not much to be said for this practice:

– ventilation of the roof-space is restricted which increases the chance of the timbers decaying (even though you say the timbers seem solid, it won’t be helping. When was the foam applied?)

– there is no insulation benefit on a cold roof i.e. one with insulation at ceiling level

– it is almost impossible to get the foam off to be able to reuse the tiles

– proper inspection of the underside of the roof is restricted – see my first point re the state of the timbers

– although foam is not a good thing regardless of the building type, be aware that it could attract a Listed Building Enforcement Notice and have to be removed and repaired. I don’t know much about this but it would be worth you looking into so you don’t get caught out later.

Check the rest of the house carefully for other ‘improvements’. Did you spot the foam and knew what it was or were you just alerted by a survey or similar?

I’ve no answer as to what you should do, maybe get a quote for the roof to be redone correctly (by somebody who works on listed buildings) and take it from there.

[Sam W]

The foam was spotted by a (very good) roofer who I contacted as I was worried about the state of other areas of the roof. Fortunately, the areas with problems don’t have the foam torching and can be repaired relatively easily.

It seems to boil down to, it’s not good, but not the end of the world. My guess is that the foam torched roof will last as long as we expect to be in the house (20 years), but will come up as an issue if and when we decide to sell.

[burton]

Find out why the foam torching was done in the first place – if it was to fix slipping tiles then the battens could already be rotten.

listing building enforcement is unlikely to happen on a grade 2, it’s more about the external appearance and character, which foam torching will not effect. I have just re slated my grade 2 in the Peak District and removed the original lime torching and replaced it with a modern membrane – I didn’t ask for lites building consent and if the Peak Park ever complain, they can go and swivel.

If you are concerned about this you could always ring the local planning authority and ask them, but take any answer with a pinch of salt as they all seem to be idiots (the planners always seem bitter as they are usually failed, architects)

[Phil]

Nothing useful to add…

We wanted to buy a Victorian railway building (actually a hotel built next to the station, by the railway company).

As well as the general build quality, it was made from proper imported stone and not the local lime-rich sandstone which crumbles badly and ends up porous as the acidic rain dissolved the lime out.

I’d have been willing to suck up the cost of sourcing replacement roof slates for a Victorian railway building.

(I wasn’t so ready for a long term flooded celar which had soaked water up in to the structural supports rotting them and warping the floors above – who knows what hidden damage and unbounded costs lurked…)