Water leaking past Klober Permo Forte breathable membrane

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I have a problem with moisture penetrating the breathable membrane of my recently retiled pitched roof. The moisture originates from the nails which secure the battens through the new breathable membrane.

The whole roof [2500 squ ft floor area bungalow with 40 degree pitch] was stripped in Aug 2012 and Klober Permo Forte breathable membrane installed under new Crest pan tiles. Mid November, after 2 days of rain, I noticed moisture seeping through the membrane in several areas and dampening the rafters. At first the Roofer who did the job thought it was due to the battens being wet when fitted and this moisture was coming out through the nail penetrations in the membrane and into the rafters.

However, the moisture has not reduced and recent inspection by the Roofer confirms the mortar used to secure the hip and ridge tiles has not cured properly and is letting water through the joints. The water is then tricking down the outside of the water proof membrane, wetting the battens and penetrating the membrane at the nail penetrations. It seems the water is tracking down past each batten at the securing nails so almost every nail penetration is exposed to a damp batten. In some areas moisture is visible over 30% of the rafters length.

The Roofer now intends to remove and re mortar all the hip and ridge tiles, which is obviously needed, but my concern is whether the Klober membrane should be letting water through at the nail penetrations in the first place? It seems to me that any slight imperfection in hip, ridge or tile sealing either now or as they age, is likely to result in the same problem in the future. Has anyone had a similar experience or can give me some advice?

PS: I’m very satisfied with the overall quality of the work done by the roofer [and it looks good to] and there is no question of him not fixing the problem but I am really concerned about the integrity of the Klober membrane.
 
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Second FMT's question really, reason for drape is to give somewhere for the water to go away from the rafter lines.

We'e fitted 1000's of square metres of Permo Forte and never had an issue with it, it is only a secondary barrier really so, as the roofer is doing, the main issue is to stop the water getting to it in the first place
 
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The reason you don't do it taught is so that if any rain does get in there (which as mentioned it shouldn't) it will trickle down the centre of the rafters. When its taught it will just trickle down and track across the roof as it likes and through any penetrations ie where the battens fix to the rafters. Anyway fix the leaks with the roof and theoretically that should be the end of it until it leaks again but if the roof is good that should be 20 years away of so.

Your roofer is an idiot btw and effectively has made the supply and fitting of the membrane a wasted exercise. I'd be inclined to ask for a refund for the supply and fitting of the membrane.
 
Thanks for the advice and I've decided to ask the manufacturers to come and inspect the membrane and its installation.

Latest update [Sept 2012

The Roofing Contractor has inspected the installation and says the ridge and hip tiles have not bedded correctly either due to incorrect installation or there being a problem with the cement not curing properly in the hot weather during installation.

The Manufacturers have examined the installation [with the Roofing Contractor present] and advise it is fit for purpose although a little tight between rafters. Their Technical Manager said the membrane will not be totally water tight, at the batten nail penetrations, if water gets under the tiles even if it does have the correct sag between rafters [Hmm - not the answer I was expecting and food for thought for anyone contemplating this material for their roof. I'd stick to good old fashioned roofing felt next time as it lasted 60 years without any sign of water getting past it.] He was not prepared to commit to saying the installation was not in accordance with the BBA certifiaction but did agree to come back if the remedial repairs to the ridge and hip tiles failed to cure the problem.

I commissioned a private Building Surveyor to also examine the installation and he advised the material had not been installed in accordance with the manufaturers BBA Certification [i.e. too tight between rafters]. He advised allowing the Roofing contractor to come and repair the hip and ridge tile problem and conduct any other repairs he deemed necessary but be vigilant this next winter for any signs of water ingress. If water is again seen to be penetrating the membrane then get the Manufacturers and Roofing Contractor back to site and with the Surveyor present he would expect the Roofer to be persuaded to completely refelt the whole roof.

The Roofing Contractor relaid all the ridge and hip tiles nearly 6 months ago [5 days wortk for 4 men as its a big roof] and since then the roof has been totally dry, even after one or two heavy down pours. So I'm hoping things are OK but expecting they will not be.

Advice to anyone getting their roof fitted re felted, get the Roofing Contractor to stipulate in his quote what method and specification he intends to use to fit the membrane i.e. as per the BBA Spec.
 

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