What's wrong with this roof i'm about to buy…

Hi all,

I have an offer in on a house – 1936 semi (the one on the left in the photo below). Had the homebuyers survey back and the roof is rated as a ‘2’. A 2 means that it is a defect that needs repairing / replacing but is not considered to be either serious or urgent.

I drove past and took a picture yesterday – below (on the left). Looks weird to me, but then i’m not a roofer / builder.

The survey says the following for the roof structure:
“The roof is framed by pitched timber rafters supported by purlins and braced by struts. Inspect of the roof framework is limited by contents within the roof space.
Although there are no serious signs of distortion to the roof framework within the roof space, there is evidence of some settlement externally. Some of the tile edges over the party wall have become raise as a result of shrinkage / settlement of the main frame. In additon there is a slight gapping to the eaves junction with the flank wall below the hip slope, possibly as a result of a slight spread of the frame.”

There is then some stuff about probably needing to strengthen the roof due to stuff having been stored in the loft.

The things that concern me is that it seems to droop in the middle – is this a problem, and secondly there is a lot more moss on the neighbours roof than on the one i’m interested in. Makes me think someone has been up there to ‘do’ something…

I don’t want to buy a house and then spend 30k on a new roof!

Big version here: http://i42.tinypic.com/2qx9smd.jpg

If in doubt, just walk away.

Well I don’t know enough about roofs to know if i’m in doubt or not. The surveyor says it’s a minor thing….

Looks minor to me and I’m a surveyor. The text is more an arse covering exercise

Not so much of an expert on roofs, more on surveyors
If there was a roof access hatch they probably stuck their head though and had a quick look, then looked from the outside.
Looks like the roof frame has sunk as they say so the roof beams are below the level of the party wall, hence the wave between the houses and the sunk ridge.
If you like the house get a structural survey done and amend the offer price for any costs implications. If not walk away.

You need to get up inside the roofspace and have a real good poke around. You should look for any timber work that has been done since it was originally built. Look for timbers that are a different colour, or have been cut in an odd manner. Look for joints that dont fit or have large gaps around them. I would expect to see timbers at least 4×2 or bigger on a roof of that age. Also look for roof felt that looks like it may have been patched in. Get your solicitor to ask specific, direct questions about the roof.

I am a Carpenter and Joiner and have worked on cut roofs like this.

Wouldn’t consider myself an expert though. <DISCLAIMER>

The surveyor says it’s a minor thing…..

He/she will be in a better position to express an opinion that anyone reading this thread.

…..some stuff about probably needing to strengthen the roof due to stuff having been stored in the loft.

Just don’t store a load of stuff up there, it’s not designed for that. The loft hatch exists so that you can have access to the loft space if necessary, not to keep a skipful of rubbish, other than perhaps some christmas decorations and a few empty suitcases.

….there is a lot more moss on the neighbours roof than on the one i’m interested in. Makes me think someone has been up there to ‘do’ something…

I doubt very much that they have been up on the roof sweeping the moss off with a stiff broom, its probably to do with how the shadow from the chimney stack falls during the hottest part of the day or something, and if they have, I wouldn’t worry about it.

With respect to sonic, it’s about the same on both sides. Are other properties in the street similar? Are there new roofs nearby.

Having asked that I should add that in my street of thirties houses, most of the semis with the North-facing side roofs have had repairs.

From what I can see, none of the nearby neighbours have non original roofs.

He/she [surveyor] will be in a better position to express an opinion that anyone reading this thread.

From the picture above, and the first post, everyone reading this thread has access to the same information as the surveyor

unless it was a proper structural survey, they would have looked through the loft hatch for a second or two (or not even bothered to do that) and then from outside.

I think i’ll get a builder to look at it.

Looks lovely that. Characterful 😉

I’d be more worried about the cable that’s stopping the house falling over, looks like it’s directly in a flight path.

they would have looked through the loft hatch for a second or two (or not even bothered to do that)

The original post suggests that they have bothered : “Inspect of the roof framework is limited by contents within the roof space.” So an inspection limited by the contents then. Presumably they were fine with what they did see.

Ok. My 2 pence worth.

The odd thing is the movement over the party wall towards the lower part of the slope.I wouldn’t be concerned over the viewable remaining section of roof.

The strut and purlin, typical design for this period, to the roof slope will be mid span hence restriction of deflection at this point. Reduced height will restrict loading to the lower section, plus the “opening” of the tiles occurs both sides of the party wall. I can only conclude it’s a deflection in the roof rafters due to them being insufficent sized for the weight and span, or poor condition due to rot or infestation.

Get up in the roof and have a look at the underside and see if the rafters “belly” and the condition of the timber, particularly at the party wall location.

I suspect it’s more to do with the clay tile on the roof, they are old and brittle and not as durable as natural slate or man made concrete.
At some point they will need replaced and they are expensive. IIRC they are hand cut and you need a lot per m2.

From the pic and wording on the valuation report, I would be tempted to suggest that the horizontal purlins (front and back sides of the roof) are not continuous across the party wall; which is fairly typical for properties of this age as it was/is cheaper to fit 2 shorter pieces and not even joint them together at the point of the party wall. In all likelihood, the ends are just sitting in the party wall masonry with not alot on top of them to prevent them from lifting should the roof belly as both sides are.

As you’ve gathered from posts above, there are a number of possible reasons as to why it has sagged, some more expensive and some not so expensive to remedy. A competent structural surveyor and/or carpenter – who can properly cut and pitch a roof will identify that.

I would also add that one area worth paying close attention to, is the gulley between the two pitches. That will carry alot of rainwater and also supports the two valley boards and rafters from the two pitched roofs facing outwards. Admittedly, there will be a solid party wall beneath, however, it would be good to look inside that part of the roof space.

I’m down south in Hants, if you’re down this way, I’d be happy to check it out for you.

Sfine mate …move in put the kettle on and work out where to put your Mancave … 😆

Purlins never used to go completely though the party wall, do they even now? Not a problem, are there enough struts?
Old rafters always “belly” dosn’t look that bad. These are machine made tiles not handmade, they look good no frost damage at all.
No undercloak on the verges, not great but not a problem just roofer being lazy. One tile missing under stack, tile fillet around stack will cause issue one day, it should be lead.
Hip ridge need repointing.
Bottom of both verges at gulley where the houses meet have been repointed suggesting work done to lead/felt, i’d check that to see what they have done
I’m a roofer BTW

Right – I am fantastically stupid. That picture up there – that’s a picture of next door, the one that I took to ‘compare and contrast’. I went back to look at it today and the penny dropped.

Please don’t hold back on calling me an idiot. 😳

Thank you all for your advice – I will certainly take it and go and have a look in the loft at the rafters etc with a builder friend of mine.

The actual roof I should have posted is this one…. which doesn’t look as bad. Good point re: gully.

As far as the man cave goes…. it used to have a garage but it was knocked down due to a leaky roof. The pad is still there, so I have a decleration signed in blood from the wife that the first thing we do is build an uber man cad 😀 (my sole requirement for the house was…. a garage. My wife is persuasive!)

Big version http://i39.tinypic.com/dyafj9.jpg

Slackalice – where abouts in hants are you? The house is in Brookwood which is next to farnborough.

BTW – I looked at the moss on the rest of the roofs in the street – on the majority far more moss on the west side – good call who ever it was that suggested it might be a shadow / sun thing!

i’d say that the second house is significantly better than the first. i always say get it done right so get someone like slackalice to do a proper costed survey/ consult and present it to the vendors and wait for a second.
i also selfishly, but i’m not local to you ,absolutely recommend a survey of the central heating system. it is the single most expensive item in the home and every month i repace a system in somebodies new home where it unexpetedly was’nt working.. dont ask for a safety cert. get a full blow by blow account costed again and save yourself a few bob and or worries..

Yep, all over the boiler. Going to get it serviced as part of the contract.

Bought our house (1937) 12 years ago now
Surveyors report had almost identical wording, roof has been fine for all that time, not needed to do anything
2 1/2 years ago we removed the entire back of the house for a big extension (doubled the house size), builder said the roof structure was A1 when I mentioned the original survey
Is probably just arse covering by surveyors if anything is even slightly suspect they have a duty to include it in the report, they will literally only have poked head into lofts pace though so no way they can tell
(did it also mention needing more ventilation in the loft space, they usually do)

(did it also mention needing more ventilation in the loft space, they usually do)

Nope, only underfloor – not enough ventilation bricks. I’m planning to solve that with a SDS drill.

Brookwood eh?
I often get the train to Brookwood to go riding round Pirbright.
Riding from your doorstep, nice.

Riding from your doorstep, nice.

Yep 🙂

Looks like normal roof settlement to me. High on the party wall and settled else where. You don’t see this on new properties as the party wall are kept slightly lower the the roof structure, then they fit wire insulation as a fire break. My place looks simular where the brickies originally built the party wall and gable end at the same hieght as the roof timbers and now 30 years on the rafters have sagged up to 50mm in place put a belly in the roof plus roof timbers were considerably smaller when mine was built. Which is no doubt the same for this proprty.

ps i’m a chippy with very good knowledge in roofing.

Hi Ewan

Please PM me.

Holyzeus & jimr both gave spot on summations. Whilst a wooden boatbuilder by training and trade, I’ve been doing oak framing for the last 10years, so whilst no expert as HZ, I’m aware of structural stuff.

As I offered, I’d be happy to have a look and then go riding – I’ve not ridden much in the N Downs 😆