How old is this roof?

[Lard]

Thought I’d share this with you…...

Mate of mine bought a lovely bungalow 11 years ago and, as I transpires, has suffered numerous roof leaks throughout that period. Having identified certain ‘issues’ I’ve ended up giving him a hand to reroof certain sections.

Here‘s 2 photos taken yesterday, have a look at take a guess at how old the roof is (in fact, the building itself)…….answer below……

…….you may have guessed it……that’s right 11 (yes, eleven) years old!

I’ve never seen such a level of deterioration (of supposed tantalised timbers) in such a young building.

 

[MARK.B.]

Maybe its not the fault of the timber but on the shoddy builders who put a colander on the bungalow instead of a roof

 

[Torx]

Many (good) roofers offer warranties 20yr on their work, shame it wasn’t sorted by the previous owner.

 

[Jacob]

Not enough battens / tiles.
I imagine everything else would have been OK it's not rocket science, but they scrimped on the tiles. If you replace them the same way you will have the same problem
https://www.marley.co.uk/blog/batten-spacing-and-installation-for-roof-tilesPS It looks like a very bad bit of jerry building so it might be worth asking if there is any come-back on builder, previous owner, surveyor etc in spite of the length of time.

 

[Sachakins]

So if he bought it 11 years ago, and its 11 years old, did he buy the property new?
Or are you saying that only the roof is 11 years old? In which case maybe only tiles where replaced when roof done, but original battens used, so they could be older, a lot older!

 

[owen]

Not enough headlap on the tiles?

 

[Jacob]

So if he bought it 11 years ago, and its 11 years old, did he buy the property new?
Or are you saying that only the roof is 11 years old? In which case maybe only tiles where replaced when roof done, but original battens used, so they could be older, a lot older!

Not the material it's a design problem. They've missed out half the tile courses. There should be another batten between each of those you can see, with a course of tiles on them. So far the rain has been kept out by the felt alone.

 

[Sachakins]

Not the material it's a design problem. They've missed out one in three tile courses. The rain has been kept out by the felt alone.

Possibly, but not knowing the property actual age, means them battens could be 25 plus years old, so combined with poor fitting, then that amount of rot would be expected, tanalised or not.

 

[Jacob]

Possibly, but not knowing the property actual age, means them battens could be 25 plus years old, so combined with poor fitting, then that amount of rot would be expected, tanalised or not.

Battens last 100 or more years, even without tanalising, in a properly built roof.
Isn't there a TV prog called Disaster DIY? They might be interested!

 

[Sachakins]

Battens last 100 or more years, even without tanalising, in a properly built roof.

That's why I said combined with poor fitting....

 

[RichardG]

Not the material it's a design problem. They've missed out half the tile courses. There should be another batten between each of those you can see, with a course of tiles on them. So far the rain has been kept out by the felt alone.

Yup, looks like they’ve laid them as if they were standard interlocking roof tiles but they appear to be more like slates which need that extra course. If that’s the case the whole roof needs to be done…and some matching tiles found.

 

[Lons]

Yup, looks like they’ve laid them as if they were standard interlocking roof tiles but they appear to be more like slates which need that extra course. If that’s the case the whole roof needs to be done…and some matching tiles found.

Yep I'd say that as well but without more information on the tiles it can't be said for certain.
If they are interlocking though it doesn't look like it from the photo then the spacing is correct.

 

[Jacob]

I spotted it because I've seen it done before - not by me I hasten to add! But that was on a little porch and no prob.
It isn't obvious to non roofers how slates or rosemaries are laid if you haven't looked hard and scratched your head a bit!

If he can't match them he could put all old on one side and all new on the other. Or mix in a random or patterned way if he can be bothered.

 

[Woody2Shoes]

Some thoughts/questions:

1) Tanalised timber will rot almost as fast as un-tanalised stuff if it spends more time wet than dry. Those battens look like they have not rotted (much) and have probably retained most of their original strength.

2) Is this an exposed location (e.g. near the sea)?

3) Assuming the level of headlap was correct, most of the problems are usually caused by poor detailing at the edges (e.g. ridges/hips/valleys and eaves sometimes too).

4) I think that modern plastic-based underlays, like the one in the photo, are generally a poor substitute for the old bitumen felt - especially the fibre re-inforced kind (5U from memory) - they're a lot easier for roofers to lay (which is why they're popular I suspect).

Which bits of the roof were leaking (and why exactly)?

 

[Woody2Shoes]

PS If they're the modern interlocking concrete tiles like this:
https://www.travisperkins.co.uk/con...ofing-tile-smooth-grey-pallet-of-192/p/808925then the minimum headlap is 100mm (presumably more for an exposed location) - from the photo of the existing tiles, the headlap looks somewhat less than 100mm (especially nearer the ridge).

 

[Matress]

There may be ventilation problem here. The tile headlap doesn't look too bad for the pitch. There's probably other problems such as bad hip and Ridge detailing but the black staining leads me to think there's a condensation problem caused by a lack of a VCL and eave ventilation.

 

[Jacob]

There may be ventilation problem here. The tile headlap doesn't look too bad for the pitch. There's probably other problems such as bad hip and Ridge detailing but the black staining leads me to think there's a condensation problem caused by a lack of a VCL and eave ventilation.

It looks to me (could be wrong) that the problem is the missing courses of tiles. This has caused the staining; rain water dripping straight through between the tiles. The VCL is fine ("Roofshield") and has been the only thing keeping the rain out.
Exactly half the tiles are missing. Unbelievable - but it has been done before. Not as a rip-off just sheer ignorance/inexperience, probably a first time DIYer

 

[MikeJhn]

Looks to me like the under cloaking membrane has been pulled taunt at the overlaps and that is where the battens have excessively deteriorated, water would be held against the batten hence the rot, at other areas the membrane is not taunt and water can pass through under the battens and between the rafters as is should do, without knowing what tiles they are its not possible to surmise if the battens are at the right spacing.

 

[Stevekane]

I have never had anything to do with roofs but I thought that with modern tiles you would have to get the battons correctly spaced because each tile has to both hook over a batten and also hook over the the two tiles below, locking everything together and making a secure roof? If you look at the first photo you can see the edge of the undisturbed tiles which I think shows this?
Perhaps it was just poor quality battens maybe on an elevation that gets driven rain?
Steve.

 

[Jacob]

Looks to me like the under cloaking membrane has been pulled taunt at the overlaps and that is where the battens have excessively deteriorated, water would be held against the batten hence the rot, at other areas the membrane is not taunt and water can pass through under the battens and between the rafters as is should do, without knowing what tiles they are its not possible to surmise if the battens are at the right spacing.

If you look at the first photo you can see tiles in situ but with a course missing - unless they are interlocking but it doesn't look like it.