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How old is this roof?

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Matress

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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
Roofshield isn't a VCL. It's breather membrane. It's hard to say what the problem is from a photo but there are signs of white spores in one of the pictures and this is a sure sign of condensation. The condensation may be forming from the water that has saturated the battens etc and hips may also be leaking. It would be interesting to see under the roofshield because there maybe another underlay.
A vapour control layer needs to be as close possible to the ceiling below.
PS. 40 Years in roof surveying.
 

Jacob

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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,.....
Plain tiles or slate also have to hook over the top of the tile below 2 courses down. You can see it here Batten Spacing and Installation for Roof Tiles | Marley
PS 50 years in bodging building work!
 
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Matress

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They look like Marley Modern Duo. On this pitch 75mm headlamp should suffice.
 

Matress

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This type of thing happens when the inside of the roof is sprayed with foam insulation.
 

MARK.B.

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Simple way to find out when it was built is to check the Deed's, they will have in most cases a build date for the property .
 

Jacob

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Be interesting to hear what the OP has to say.
 

Jonm

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They look like Marley Modern Duo. On this pitch 75mm headlamp should suffice.
The headlaps are varying, some look somewhat less than 75mm. Perhaps the pitch of the roof with the tiles removed is less than the one we can see that would reduce the headlaps further.

“The building” is 11 years old, implies new build so there should be NHBC or similar insurance cover.

Be interesting to get some more info from Lard.
 

Woody2Shoes

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They look like Marley Modern Duo. On this pitch 75mm headlamp should suffice.
It's not obvious what they are, but some of the headlaps don't look like as much as 75 - which ought to be adjusted upwards anyway, based on levels of exposure - something tells me this roof could be in quite an exposed spot.
 

Lons

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They look like Marley Modern Duo. On this pitch 75mm headlamp should suffice.
Yep
If that's what they are and it's by no means certain then they specs are straight forward.
Modern smooth 75mm lap at 22.5 deg pitch / 100mm at 17.5 deg pitch
Modern granular 75mm at 30 deg and 100mm at 25 deg


I used moderns regularly as they are common around this area and in fact on my own house as well so am well used to the specs, just checked them in case it had changed in the last few years, they haven't! Page 19 of the catalogue 2021 Product Catalogue.pdf
 

Lard

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Thanks for all the ideas/questions/responses…..I’ll give you more info (sorry, I didn’t offer it before as I simply thought you’d like to see how bad this roof was).

The WHOLE house was a self-build 11yrs ago and, although I knew my mate had bought it, I didn’t realise the original owner/builder had hardly lived in it himself. By all accounts he did the roof himself.

I’m a retired QS, have a background in construction, did spend a fair few years as a building surveyor and can also turn my hand to most practical jobs which is why I’ve ended up getting involved. He originally asked me to come and have a look and give an opinion and, due to subsequent crazy quotes and lack of roofers, I offered to do the work for him (together with another mate and him labouring).

It‘s quite a complicated roof too (see google earth photo below) and so not a simple case of stripping and replacing…..cuts, cuts, cuts and more bloody cuts…..why oh why did I offer to help :cry::cry::)

Anyway I digress…..the CLAY INTERLOCKING tiles are Sandtoft Cassius and their spec dictates, for the pitch of this house, a minimum gauge of 75mm. It was very quickly apparent that the gauge was incorrect (as it turns out on ALL bar one of the slopes) - Firstly, and unbelievably, because when viewed from up high on a ladder you could, in several places actually see the nail holes on the top of the tiles (I kid you not!!!!!!). From the ground nothing looked particularly amiss. Secondly, through simple measurement and calculation, it shows that the roofer was one course shy. Thirdly, having now stripped some of the slopes, we were able to check (via watermarks) what the actual vertical head-laps had been….although some were borderline 75mm, most were way out and often equated to something akin to 50mm.

Even putting all of this aside for a mo, I’m still flummoxed by some of the more ‘questionable’ issues we have found like…1. First course on SOME slopes commenced at the very edge of the fascia with no attempt to overhang into the guttering. 2. Many instances of broken side-laps thus allowing any rainwater to immediately pass through to the membrane below (and so continually soaking certain areas of batten). 3. Poorly detailed GRP valley construction (in my opinion) which, debatably, would cause any water that works it way through the tiling to by-pass the valley itself and soak though to the underside membrane. 4. The valleys were all constructed unsupported - it appears that someone has walked up the centre of some and caused the fixing nails to be ‘ripped out’, meaning that one side of the valley was left somewhat unfixed (albeit held down with the weight of tiles above)…..this resulted in the finding of an enormous amount of ‘rubble’ underneath them when removed.

I’m still very surprised that the tanalised batten is so rotten…I’ve never seen anything this bad on such a young roof. It’s made me consider the potential limitations of treated timber in certain conditions.

I’ve got to keep reminding myself that the roof is only 11yrs old.

The daft part is that in other areas the original roofer has shown glimpses of roofing ’tricks’ indicating, perhaps, that he DID know what to do……it honestly is a head scratcher to work out WHY he did what he did.

In regard to exposure - Nowhere near the sea. It’s not that bad, in general, and seems that only two ‘faces’ take the worst of the weather and one of those has the correct gauge????? (and so we’re not touching it in the main areas). We’ve already complete the other and am now on a forth slope (loads of slopes, see photo). We’ve also agreed/decided to not do any work on some other slopes as these are not/have not caused any problems as yet.

In regard to ventilation - My mate wants rid of all cement mortar and so in addition to replacing the valleys (now also supported) we’re also converting the ridges to ventilated and will be adding soffit vents as I don’t think this current ‘lack of’ helped out his situation even though all of the membranes are breathable…..I’ve had a few conversations with some of the technical department boys for both the original membrane and new ridge kits and it’s actually been interesting to discuss the relative merits and issues with breathable felts and the need (perhaps) to add additional ventilation.

There’s probably more I can add but this’ll do for now.
 

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Jacob

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Thanks for all the ideas/questions/responses…..I’ll give you more info (sorry, I didn’t offer it before as I simply thought you’d like to see how bad this roof was).

The WHOLE house was a self-build 11yrs ago and, although I knew my mate had bought it, I didn’t realise the original owner/builder had hardly lived in it himself. By all accounts he did the roof himself.

I’m a retired QS, have a background in construction, did spend a fair few years as a building surveyor and can also turn my hand to most practical jobs which is why I’ve ended up getting involved. He originally asked me to come and have a look and give an opinion and, due to subsequent crazy quotes and lack of roofers, I offered to do the work for him (together with another mate and him labouring).

It‘s quite a complicated roof too (see google earth photo below) and so not a simple case of stripping and replacing…..cuts, cuts, cuts and more bloody cuts…..why oh why did I offer to help :cry::cry::)

Anyway I digress…..the CLAY INTERLOCKING tiles are Sandtoft Cassius and their spec dictates, for the pitch of this house, a minimum gauge of 75mm. It was very quickly apparent that the gauge was incorrect (as it turns out on ALL bar one of the slopes) - Firstly, and unbelievably, because when viewed from up high on a ladder you could, in several places actually see the nail holes on the top of the tiles (I kid you not!!!!!!). From the ground nothing looked particularly amiss. Secondly, through simple measurement and calculation, it shows that the roofer was one course shy. Thirdly, having now stripped some of the slopes, we were able to check (via watermarks) what the actual vertical head-laps had been….although some were borderline 75mm, most were way out and often equated to something akin to 50mm.

Even putting all of this aside for a mo, I’m still flummoxed by some of the more ‘questionable’ issues we have found like…1. First course on SOME slopes commenced at the very edge of the fascia with no attempt to overhang into the guttering. 2. Many instances of broken side-laps thus allowing any rainwater to immediately pass through to the membrane below (and so continually soaking certain areas of batten). 3. Poorly detailed GRP valley construction (in my opinion) which, debatably, would cause any water that works it way through the tiling to by-pass the valley itself and soak though to the underside membrane. 4. The valleys were all constructed unsupported - it appears that someone has walked up the centre of some and caused the fixing nails to be ‘ripped out’, meaning that one side of the valley was left somewhat unfixed (albeit held down with the weight of tiles above)…..this resulted in the finding of an enormous amount of ‘rubble’ underneath them when removed.

I’m still very surprised that the tanalised batten is so rotten…I’ve never seen anything this bad on such a young roof. It’s made me consider the potential limitations of treated timber in certain conditions.

I’ve got to keep reminding myself that the roof is only 11yrs old.

The daft part is that in other areas the original roofer has shown glimpses of roofing ’tricks’ indicating, perhaps, that he DID know what to do……it honestly is a head scratcher to work out WHY he did what he did.

In regard to exposure - Nowhere near the sea. It’s not that bad, in general, and seems that only two ‘faces’ take the worst of the weather and one of those has the correct gauge????? (and so we’re not touching it in the main areas). We’ve already complete the other and am now on a forth slope (loads of slopes, see photo). We’ve also agreed/decided to not do any work on some other slopes as these are not/have not caused any problems as yet.

In regard to ventilation - My mate wants rid of all cement mortar and so in addition to replacing the valleys (now also supported) we’re also converting the ridges to ventilated and will be adding soffit vents as I don’t think this current ‘lack of’ helped out his situation even though all of the membranes are breathable…..I’ve had a few conversations with some of the technical department boys for both the original membrane and new ridge kits and it’s actually been interesting to discuss the relative merits and issues with breathable felts and the need (perhaps) to add additional ventilation.

There’s probably more I can add but this’ll do for now.
Phew! All is revealed! :unsure:
 

Lard

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I’ll tell you one advantage to helping out a mate…..his wife is a ‘feeder’ and so I haven’t had to take any food with me whatsoeve! :love:
 

eribaMotters

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Assuming the rafters are 400 centres then those battens must be near 250/300mm apart. They should be a lot closer. I've had to strip and re-felt and batten part of my roof at two years old that was tiled with Marley tiles, batten spacing 190mm as in specification. It had leaked since day 1.

Colin
 

Jacob

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Yeah, sorry….went on a bit
No it was jolly interesting! :LOL:
Looking at the roof plan it looks like the poor sod could have been overwhelmed by sheer complexity due to mad/bad design in the first place.
 
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Adam W.

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It's not that difficult, set the correct gauge allowing for the lap at the ridge and off you go.

I can't see why people struggle with roofs, unless they're incompetent.
 

MARK.B.

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I think i would be advising your mate to get other things checked out in the house like the electrics, the roof was clearly bodged in a bad way so just what else is lurking waiting to rear its ugly head :eek: You say you are leaving some areas untouched as they seem OK at the moment :unsure: given what you have already discovered in the areas you have redone , would it not be wise to at least strip an area to see what if anything may be wrong but hidden from sight :)
 
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