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5 page thread with several contributors discussing the problem.Surely better to ask those with experience and join a thread already discussing the issue.
Noise from GRP flat roof
- Thread starter ajs1954
- Start date
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You could always start a new thread & link to this one.....but the key to GRP rooves is the deck has to be rock solid. The system I use recommends T & G OSB3 - if you choose to use plain sheets (which I have on some cos cost) ALL the joints MUST be supported. I've not done a warm roof but I'd be suspicious about being able to get a solid enough fix through Celotex or similar and the joints (on plain sheets) would not be supported.
I do wonder whether the warm roof sketch is suitable for GRP- with a cold roof the roof can radiate absorbed heat in both directions (up to the sky and down into the roof space), with a warm roof the underside of the roof will get very hot because of the insulation thus giving an extreme temperature difference across 18mm of OSB which would explain all the expansion noises.
I do wonder whether the warm roof sketch is suitable for GRP- with a cold roof the roof can radiate absorbed heat in both directions (up to the sky and down into the roof space), with a warm roof the underside of the roof will get very hot because of the insulation thus giving an extreme temperature difference across 18mm of OSB which would explain all the expansion noises.
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thanks oldbutnotdead. I think you're right. Definitely a movement noise. Having added some noggins and toenailed some extra screws from the joists up into the firings theres a definite improvement. ( ceiling not plasterboard). I can make the noise happen if i push up on the roof with a 3x2 so its definitely movement.
Im hoping extra noggins will add more rigidity and when the plasterboard goes on , and I will use heavier fire rated , this weight will also help inhibit movement.
I think as a final resort some sedum will help , thermally as a barrier but also as a weight , holding the roof down , limiting movement again.
Im hoping extra noggins will add more rigidity and when the plasterboard goes on , and I will use heavier fire rated , this weight will also help inhibit movement.
I think as a final resort some sedum will help , thermally as a barrier but also as a weight , holding the roof down , limiting movement again.
You could try putting some polyurathane on all the joists and noggins if you have access underneath to stop the boards moving.
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Hi, joining thread as wondered if anyone had an update had my flat roof installed nearly 3 years ago as part of a loft conversion. builder not really interested so have had three years of pretty much hell with the noise its relentless. and trying to find a reason as to why this is happening. i have read every thread but no one seems to have a solution yet?
I am not an expert and struggle to understand some of the terminology used.
my roof is grey and looks like a painted surface i have attached a picture.
Bangs / creaks day and night this noise is all over the roof not one place it can be a huge loud bang, lots of bangs or sometimes sounds like someone running along roof, sometimes there is a creak and then you know its going to start banging.
definitely contraction and expansion with less noise on cloudy mild days (thank god) not affected by the wind.
the builder has tried to remedy noise.
1. put 2 chimney air vents on top, this had no effect
2. changed the vented facia to non vented facia, this had no effect
a number of months ago he agreed to remove the roof and replace it i would need to pay for the parts and he would cover the labour, this has yet to materialise but my concern is if they/I don't understand the problem then the banging may just continue. i am having to get a loan out to cover this work and i'm just so worried it wont help
i know this is a long thread starting a few years ago but would welcome any updated thoughts or advice
many thanks in advance have included a few pictures in the hope these may help.
Jo
I am not an expert and struggle to understand some of the terminology used.
my roof is grey and looks like a painted surface i have attached a picture.
Bangs / creaks day and night this noise is all over the roof not one place it can be a huge loud bang, lots of bangs or sometimes sounds like someone running along roof, sometimes there is a creak and then you know its going to start banging.
definitely contraction and expansion with less noise on cloudy mild days (thank god) not affected by the wind.
the builder has tried to remedy noise.
1. put 2 chimney air vents on top, this had no effect
2. changed the vented facia to non vented facia, this had no effect
a number of months ago he agreed to remove the roof and replace it i would need to pay for the parts and he would cover the labour, this has yet to materialise but my concern is if they/I don't understand the problem then the banging may just continue. i am having to get a loan out to cover this work and i'm just so worried it wont help
i know this is a long thread starting a few years ago but would welcome any updated thoughts or advice
many thanks in advance have included a few pictures in the hope these may help.
Jo
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As you'll have seen, the main cause of banging/creaking is the deck not being secured to the joists and/or deck joints not properly made and/or joists not securely fixed (gravity is not sufficient).
Recommended deck for fibre glass is T & G 18mm OSB. If you use square edge boards you must support every join.
There needs to be at least 10mm clearance between deck and any walls.
If yours is insulated, fixing the deck through rigid insulation is unlikely to be successfull- insulate between and under the joists not above them.
There are loads of supplier videos and instruction sheets online, Cure-it is one major brand, there are others.
Recommended deck for fibre glass is T & G 18mm OSB. If you use square edge boards you must support every join.
There needs to be at least 10mm clearance between deck and any walls.
If yours is insulated, fixing the deck through rigid insulation is unlikely to be successfull- insulate between and under the joists not above them.
There are loads of supplier videos and instruction sheets online, Cure-it is one major brand, there are others.
Thank you for your reply I’m going to look at the video and show your comments to the builder so when they take the roof off to replace each of these points can be checked
I think they insulated between joists and above but not 100% sure
I’m so over the whole thing and just don’t have anyone to help fight my corner so the banging and sleepless nights continue 
Jo
I think they insulated between joists and above but not 100% sure
I’m so over the whole thing and just don’t have anyone to help fight my corner so the banging and sleepless nights continue
Jo
Glue it and screw it next time would be wise.
Not a bad plan that. Also use shanked screws (so the deck is pulled down onto the joists) and lay the boards correct way up (system i use says side with writing up, apparently gives the resin a better bond and fills the joins in t & g more effectively).
Thank you for the suggestion and the link will certainly mention it if they do indeed come back.
So it sounds like the problem is defiantly the ply or insulation not secured properly so banging when expansion and contraction occurs and sounds so loud because its like a drum effect ? so many different views but this does make sense to me
someone said that they did have the roof screwed down again from the top and re sealed but this didn't seem to help?
In your experience would it be worth testing this theory with weighting down the roof first although how easy being the loft conversion im not sure
open to any advice that will keep costs lower and actually work
many thanks
Jo
So it sounds like the problem is defiantly the ply or insulation not secured properly so banging when expansion and contraction occurs and sounds so loud because its like a drum effect ? so many different views but this does make sense to me
someone said that they did have the roof screwed down again from the top and re sealed but this didn't seem to help?
In your experience would it be worth testing this theory with weighting down the roof first although how easy being the loft conversion im not sure
open to any advice that will keep costs lower and actually work
many thanks
Jo
From the photo's it looks like grp fibre glass roof.
Many people on here said they thought EPDM was better. We have EPDM roof (warm roof) and a glass skylight, and the roof also makes popping noises at night and morning when sun comes up. It's not every day but does happen. Has to be something to do with fixings of the ply/OSB rather than the roofing materials...
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On a warm roof deck the screws should penetrate into the joists at least 40mm and it should be one continuous screw so on a 8x4 sheet around 24-26 fixings.The boards should be laid brickbond and supported on the edges.
Each board should have a 3mm gap and 20 mm upto a wall and in case of a wooden upstand for a roof light
Again a gap the timber fillet up against the timber upstand should be screwed into the upstand and not the deck allowing the deck to expand and contract.
A vapour barrier should also be installed.
And also worth putting noggins in between joists for extra stability.
The amount of times I see all the above ignored by who Evers building the roof is unbelievable I’m not saying that’s the answer to every creaking roof but the basics need to be right to start off with.
Each board should have a 3mm gap and 20 mm upto a wall and in case of a wooden upstand for a roof light
Again a gap the timber fillet up against the timber upstand should be screwed into the upstand and not the deck allowing the deck to expand and contract.
A vapour barrier should also be installed.
And also worth putting noggins in between joists for extra stability.
The amount of times I see all the above ignored by who Evers building the roof is unbelievable I’m not saying that’s the answer to every creaking roof but the basics need to be right to start off with.
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