David paul Posted July 26 Share Posted July 26 Hi All, I had a new roof installed (2 years) and am concerned that the breathable membrane is very taught.The company that did the roof do a lot of work for the local council and i considered that a good sign (I’m now not so sure)anyhow after getting a little suspicious after watching their work practices I got concerned.I know little on such matters but overheard remarks and cowboys was mentioned.how will I know if the membrane has been fitted correctly and over what time span(can I rest easy after 2 years.)60pcof the roof was boarded before I bought the property.Thanks for your help Link to comment Share on other sites More sharing options...
SteamyTea Posted July 26 Share Posted July 26 Welcome. I don't know too much about roofs, but I think some modern membranes care meant to be taught, while older types are saggy, by design. Do you know what make the membrane is? Others will be along who know a lot more than me. @joe90 Link to comment Share on other sites More sharing options...
joe90 Posted July 26 Share Posted July 26 The problem with tight membranes is condensation and dust etc can build up behind the battens leading to timber rot. I prefer membranes to drape slightly but there are all sorts of modern membranes that act differently and have specific fitting requirements. Link to comment Share on other sites More sharing options...
scottishjohn Posted July 26 Share Posted July 26 2 minutes ago, joe90 said: The problem with tight membranes is condensation and dust etc can build up behind the battens leading to timber rot. I prefer membranes to drape slightly but there are all sorts of modern membranes that act differently and have specific fitting requirements. surely if first battons are vertical this will not happen as any condensation will run down the sides of them and not gather up ? Link to comment Share on other sites More sharing options...
joe90 Posted July 26 Share Posted July 26 (edited) 4 minutes ago, scottishjohn said: surely if first battons are vertical this will not happen as any condensation will run down the sides of them and not gather up ? You mean counter battens, yes, a very good way of getting over tight membranes. https://www.facebook.com/watch/?v=769527770912079 Edited July 26 by joe90 Link to comment Share on other sites More sharing options...
scottishjohn Posted July 26 Share Posted July 26 Just now, joe90 said: You mean counter battens, yes, a very good way of getting over tight membranes. does anybody NOT fit counter battons? my present house was built with just one set -horizontally and caused a mass gather up of dust and crap behind them and casued rot at lower 4 corners of the roof Ibut yes i know inenglend these used to just use one set of battons with saggy tar pper between them and trusses but never in scotland we always went for sarking boards ,but yes some went for just the one row of battons,like my house -- to save maybe £100 on a roof is silly. but then alot of houses here use slates do all you get is breather membrane then slates nailed on -no battons I suppose the condenstaionis only going to happen if you have a badly vented cold roof - and a warm roof shouldn,t get that anyway Link to comment Share on other sites More sharing options...
G and J Posted July 26 Share Posted July 26 We’re planning a cold roof, and whilst I’ve not read up as much on this as perhaps I should, I’d gathered that counterbattens and ridge vents would mean the tiles and the solar pv panels will be nicely ventilated behind. Given the airtight(ish) envelope of the house that should mean that little moisture found it’s way from the house to the loft, and what does find it’s way in there will escape through the breather membrane. All that I think means no soffit vents so no plague of insects in the loft. Does all that stack up? Link to comment Share on other sites More sharing options...
David paul Posted July 27 Author Share Posted July 27 Hi steamytea,unfortunately after 2 years I can’t remember the make.my concern is the council always go for lowest cost when farming work out so I can’t imagine it’s top spec(which is worrying) as they obviously use the same brand on their private work..The other concern sub contractors for councils don’t I think have particular care. I should have gone for a private local company.After 2 years I’m hopeful that any faults after 2 years would have surfaced but I’m not confident. any thoughts Joe90 and others please .Thanks from a complete novice Link to comment Share on other sites More sharing options...
joe90 Posted July 27 Share Posted July 27 The problem is to rectify this the roof needs stripping and re placing and as so many roofs are like yours I don’t doubt it will last 20 years, do you really want to spend money now when it could last a fairly long time 🤷♂️ Link to comment Share on other sites More sharing options...
David paul Posted July 27 Author Share Posted July 27 Thanks Joe 90. 20years well better than 10 I guess(life and learn BUTi should have done that already 😁at my age) do you envisage problems and if so how will they show ?Thanks Link to comment Share on other sites More sharing options...
joe90 Posted July 27 Share Posted July 27 If and when moisture backs up on the battens they will rot eventually and this will lead to tile slippage. Link to comment Share on other sites More sharing options...
Dave Jones Posted July 28 Share Posted July 28 On 26/07/2024 at 21:56, scottishjohn said: does anybody NOT fit counter battons? everyone with a standard roof as there is no need. Link to comment Share on other sites More sharing options...
David paul Posted July 28 Author Share Posted July 28 Thanks Joe and all,I have to put it out of my mind and stop overthinking. It is what it is now unfortunately.Thanks and regards. 1 Link to comment Share on other sites More sharing options...
flumpery Posted August 1 Share Posted August 1 Hey David Jumping on this a little late; but just in case anyone else sees this: for over timber rafters or counter battens, installation guidelines for most breathable membranes require there to be a drape in order for them to function properly https://www.roofgiant.com/breather-membrane-guide/ https://www.roofingsuperstore.co.uk/help-and-advice/project-guides/pitched-roofing/how-to-install-breathable-roof-membrane/ However they can be installed fully supported with sarking board or rigid insulation as is the norm for Scotland roofs (usually put in new build or refurbishment in more extreme weather prone areas) Also of relevance - for sarking boards if you have a tiled roof the "use of counter battens and tiling battens over the breathable membrane allow for water drainage and attachment of the tiles" [https://www.kingspan.com/gb/en/knowledge-articles/what-are-sarking-boards/] Link to comment Share on other sites More sharing options...
David paul Posted August 1 Author Share Posted August 1 Hi flumpery,thanks for your reply and attachment. Strangely enough I have just come in after checking out a new roof (no tiles as yet) in the next street,the membrane looks much better quality and also I’ve noticed my builders didn’t bother with a tray .so my anxiety levels are pretty high.i am in west wales on the coast so no darling boards fitted.I’m sure I should have got reputable builders(I thought they were as they get a lot of work from local council authority)but I guess Theo is a reason with cost to that) Link to comment Share on other sites More sharing options...
David paul Posted August 2 Author Share Posted August 2 Final question,with taught membrane and no eaves support tray(although the membrane does reach a little further into guttering)what will be the signs of problems and scottishjohn how did you know about rot at lower corners?. The bungalow is about 50 years of age and had material like bitumen as a membrane with no support eaves tray(I guess that is a new addition)I never had any problems apart from tearing I of membrane Link to comment Share on other sites More sharing options...
joe90 Posted August 2 Share Posted August 2 As I pointed out earlier tile slippage due to rotten battens can happen but not for many years IMO. Eaves trays are a modern thing, felt left in sunlight will disintegrate eventually (and looks rubbish 🤷♂️). Link to comment Share on other sites More sharing options...
David paul Posted August 3 Author Share Posted August 3 Thanks joe90, sorry to ask another but when I had new roof 2years ago no eaves support trays were fitted,would you recommend installing (bungalow built around 1965) Link to comment Share on other sites More sharing options...
David paul Posted August 3 Author Share Posted August 3 Extra info if relevant.new gutters and facia boards 15 years ago .thanks Link to comment Share on other sites More sharing options...
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