New roof problem, Any roofers out there?
Discussion
Hi all. Just had a new roof installed on my house. Now we've had new grp fibreglass dry valleys installed and now we are getting some condensation on the underside of the valleys. The roofer has not run a length of membrane down the full length of the valley of which i believe he should have done from reading on the web.
Is there anyway round this without taking tiles off and the valleys out to put in a layer of membrane? The scaffold is still up at present for at least another week or so, so am i justified in getting him back out to run a layer of membrane down to stop the drips. Or would it be a condensation issue and more ventilation required? Im 90% percent happy with the rest of the roof but this is causing problems at present and i would like some info if possible.
Cheers.
Is there anyway round this without taking tiles off and the valleys out to put in a layer of membrane? The scaffold is still up at present for at least another week or so, so am i justified in getting him back out to run a layer of membrane down to stop the drips. Or would it be a condensation issue and more ventilation required? Im 90% percent happy with the rest of the roof but this is causing problems at present and i would like some info if possible.
Cheers.
Hi, cold roof. About 100mm of insulation at present. The soffits have vents approx 1m apart. Dry ridge, hip and valleys installed during the re roof along with til-r breathable membrane. The roofer hasnt put any membrane or real support boards under the fibreglass valleys. There is a wooden board of sorts along one side of each of the valleys but this was there originally and is part of the roof structure as its been extended. Now i gather the support boards in practice dont really get installed under grp valleys but surely there should be membrane running underneath??
Cheers.
Cheers.
Yes the breather membrane should have been installed under the valley
Your best long term option is to call the guy back
Also if you have had a complete new roof ,the insulation should be upgraded to meet currant regs i.e. 180mm to the entire roof area
Building control will insist on that
Your best long term option is to call the guy back
Also if you have had a complete new roof ,the insulation should be upgraded to meet currant regs i.e. 180mm to the entire roof area
Building control will insist on that
Yes the breather membrane should have been installed under the valley
Your best long term option is to call the guy back
Also if you have had a complete new roof ,the insulation should be upgraded to meet currant regs i.e. 180mm to the entire roof area
Building control will insist on that
Your best long term option is to call the guy back
Also if you have had a complete new roof ,the insulation should be upgraded to meet currant regs i.e. 180mm to the entire roof area
Building control will insist on that
Building control do not need to be involved in a re roof unless it is a totally different change of covering. Even then they don't have any say in thermal upgrades unless you remove the old at the same time.
Also the BCO here specs 130mm of PIR board for roof spaces, is your 180mm a guess or is this what you have been told?
Also the BCO here specs 130mm of PIR board for roof spaces, is your 180mm a guess or is this what you have been told?
A quick question to the roofers if I may?
The GRP valleys are supposed to be extended over the bargeboards/fascias so any water running down the valleys runs straight into the gutters, right?
The reason I ask is that the guys who did mine reckoned that wasn't 'normal', and they left the valleys terminated behind the barges/fascias, so the water ran down the valleys and into the trough formed by the valley pressing the membrane down behind the fascias, so it couldn't escape anywhere. Needless to say, on the first rainy day the water pissed in behind the fascias and ended up leaking inside the house.
I had the roofers re-do it all, extending the valleys into the gutters, which annoyed them but cured the leaking.
The GRP valleys are supposed to be extended over the bargeboards/fascias so any water running down the valleys runs straight into the gutters, right?
The reason I ask is that the guys who did mine reckoned that wasn't 'normal', and they left the valleys terminated behind the barges/fascias, so the water ran down the valleys and into the trough formed by the valley pressing the membrane down behind the fascias, so it couldn't escape anywhere. Needless to say, on the first rainy day the water pissed in behind the fascias and ended up leaking inside the house.
I had the roofers re-do it all, extending the valleys into the gutters, which annoyed them but cured the leaking.
Super Slo Mo said:
A quick question to the roofers if I may?
The GRP valleys are supposed to be extended over the bargeboards/fascias so any water running down the valleys runs straight into the gutters, right?
The reason I ask is that the guys who did mine reckoned that wasn't 'normal', and they left the valleys terminated behind the barges/fascias, so the water ran down the valleys and into the trough formed by the valley pressing the membrane down behind the fascias, so it couldn't escape anywhere. Needless to say, on the first rainy day the water pissed in behind the fascias and ended up leaking inside the house.
I had the roofers re-do it all, extending the valleys into the gutters, which annoyed them but cured the leaking.
That is unusual. Sometimes one will make a lead trough at the bottom. I don't like them anyway, lead all the way.The GRP valleys are supposed to be extended over the bargeboards/fascias so any water running down the valleys runs straight into the gutters, right?
The reason I ask is that the guys who did mine reckoned that wasn't 'normal', and they left the valleys terminated behind the barges/fascias, so the water ran down the valleys and into the trough formed by the valley pressing the membrane down behind the fascias, so it couldn't escape anywhere. Needless to say, on the first rainy day the water pissed in behind the fascias and ended up leaking inside the house.
I had the roofers re-do it all, extending the valleys into the gutters, which annoyed them but cured the leaking.
If you replace more than 25% of a roof then you should really apply for building regs, it used to be only needed if you were replacing a slate roof for tiles i.e adding more weight to the existing roof structure, but now its all to do with thermal regs. Having said that a few roofers I know turn a blind eye.
Hi thanks for the replies. Have called him back to address the problem and he said there was not much he could do today with the icy conditions on the roof but he said he will phone back and have a look. So that remains to be seen.
The other problem i have is that the breathable membrane installed is getting some bad condensation on it at present but only on one side of the house from what i can see. The membrane is dry on top so no water is getting past the tiles but not below. The tiles are very cold on the underside due to the weather. Also a bit stranger is that the dpc run along the eaves at that side seems to have condensation on the underside too.
The soffits have a few vents in about every 1200mm apart so im thinking of installing a few more to see if that helps. At present I've spent £4300 and its worse than it was before for leaking! I'm not sure these breathable membranes are the all singing and dancing things they claim to be.
With regard to the loft insulation. It is saturated in places due to the roof being installed in winter and the condensation dripping on to it? i havent had chance to get it all out yet and replace with new stuff. It is also not to minimum depth which is something that needs sorting.
I suppose there is a lot of moisture in the loft at present, water tank not properly lagged and sealed, those valleys being so condensated and the damp insulation. The loft hatch is not isulated and sealed as well so i suppose its asking for trouble at the moment along with the heating being whacked up high!
Cheers again
The other problem i have is that the breathable membrane installed is getting some bad condensation on it at present but only on one side of the house from what i can see. The membrane is dry on top so no water is getting past the tiles but not below. The tiles are very cold on the underside due to the weather. Also a bit stranger is that the dpc run along the eaves at that side seems to have condensation on the underside too.
The soffits have a few vents in about every 1200mm apart so im thinking of installing a few more to see if that helps. At present I've spent £4300 and its worse than it was before for leaking! I'm not sure these breathable membranes are the all singing and dancing things they claim to be.
With regard to the loft insulation. It is saturated in places due to the roof being installed in winter and the condensation dripping on to it? i havent had chance to get it all out yet and replace with new stuff. It is also not to minimum depth which is something that needs sorting.
I suppose there is a lot of moisture in the loft at present, water tank not properly lagged and sealed, those valleys being so condensated and the damp insulation. The loft hatch is not isulated and sealed as well so i suppose its asking for trouble at the moment along with the heating being whacked up high!
Cheers again
Another quick few questions.
Would any vents at high level help? It has a dry ridge system at present.
Would there be any use of a vapour control layer in the loft and how would this be installed?
What about these lapvents you can buy?
And is the membrane he has used in the first place any good? Its TIL=R membrane. As far as i can see its not the cheapest but not the most expensive too.
Cheers again
Would any vents at high level help? It has a dry ridge system at present.
Would there be any use of a vapour control layer in the loft and how would this be installed?
What about these lapvents you can buy?
And is the membrane he has used in the first place any good? Its TIL=R membrane. As far as i can see its not the cheapest but not the most expensive too.
Cheers again
Edited by Liam999uk on Sunday 28th December 21:57
Gtom said:
Building control do not need to be involved in a re roof unless it is a totally different change of covering. Even then they don't have any say in thermal upgrades unless you remove the old at the same time.
Also the BCO here specs 130mm of PIR board for roof spaces, is your 180mm a guess or is this what you have been told?
BCO Regulations state 180mm of rolled insulations to ceiling rafters (i.e. Rockwool)Also the BCO here specs 130mm of PIR board for roof spaces, is your 180mm a guess or is this what you have been told?
Totally different to 10mm between and 40mm below rafters which is needed if your insulation envelope extends into the roof void
As stated elsewhere if more than 25% of the covering is changed then the insulation needs to be upgraded and BC should be notified
So no not really a guess
roofer said:
TIL R is crap, it's SIG groups own manufactured system.
If you have a dry ridge, why is it not vented ? Has the insulation been pulled back from the eave to allow airflow ? Any heat sources in the loft ? Spotlight shrouds ?
Hi, why is it crap though whats the difference from other more expensive makes just out of interest. It did withstand quite a bit of wind and rain thrown at it when it was being installed. That side of the house was exposed for a couple of days during roofing and it did hold ok a bit of water got through where it was nailed but not too much. The top of the membrane is perfectly dry at present. The tiles are frosty underneath but the membrane is quite wet underneath on that one side of the house.If you have a dry ridge, why is it not vented ? Has the insulation been pulled back from the eave to allow airflow ? Any heat sources in the loft ? Spotlight shrouds ?
The insulation is pulled back but as i said earlier maybe the soffits need more vents as there is only about 5 on a 7m length that side of the house.
With regard to the dry ridge it looks fine from the outside. He has used the marley eternit system with the roll out kit. Now when he was installing it i was wondering why he didnt use the stand up bracket that come with it. He has nailed the battens straight along the top of the rafter on the angle then screwed into that instead of using that bracket. So in effect one side maybe has had its ventilation blocked a bit and the other not so much. The membrane goes over the apex of the roof also.
The insulation is sogged in places on the side of the house where the problem is. Now im presuming this is due to the condensation and wet when the roof was installed and really it needs ripping out. No other heat sources really other than 2 flourescent lights for when we go up in the loft. The water tank is there like i said. Tbh at the moment i feel like selling the house again, only been here 8 weeks!!!!
Cheers
roofer said:
It's crap as a breather membrane. That roof has a serious lack of airflow, and there is definitely heat getting in there. It wants an over fascia vent right along the eave, and inline or ridge vent installing.
Would adding more under soffit vents suffice? It has just turned into a nightmare really. But i need it sorting before the scaffolding comes down. I forgot to add the two rooms under where the problem is one has just been plastered and they both dont have any central heating at present. I agree with the airflow as it doesnt feel particularly breezy in the loft. It feels cold, you can see your breath, but not as cold as outside. When it comes to re doing the insulation is it worth adding a vcl under the insulation? If so how best to do it?
Cheers again
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