Massive movement on flat roof membrane lifting in wind.

[Limping2040]

Massive movement on flat roof membrane lifting in wind.

This roof is a dorma conversion up in the loft space.

Had a new flat roof before I bought it but I've been told before it started lifting that it was placed on top of the old membrane.

Video of movement here.

https://www.youtube.com/watch?v=Gck8Ctktp0Q Sorry its upside down

How do I solve this issue, and why had it likely happened?

Does the sheet need to be lifted put back down and some weight added too it?

[JohnMo]

Ours isn't flat but at 12 deg.  Covered in EPDM membrane.  Do see some lifting in high wind as air flows between it and the underlay.  But the strips are about 1m wide and are screwed down through spreader plates every 300 or so mm along the long edge, the next strip overlaps and is welded to seal.

 

Either the new roof cover wasn't mechanical fixed correctly or if bonded not bonded correctly.

 

Did it come with any warranty?

[Limping2040]

27 minutes ago, JohnMo said:

Ours isn't flat but at 12 deg.  Covered in EPDM membrane.  Do see some lifting in high wind as air flows between it and the underlay.  But the strips are about 1m wide and are screwed down through spreader plates every 300 or so mm along the long edge, the next strip overlaps and is welded to seal.

 

Either the new roof cover wasn't mechanical fixed correctly or if bonded not bonded correctly.

 

Did it come with any warranty?

 

I bought the house two years ago and it was replaced a year or so before that.

 

Not sure if that's going to be avaliable. 

 

I assume it's going to be a new roof again?

[Dave Jones]

100% its a bodged warm roof. If wind can lift it moisture certainly will be getting in.

[Limping2040]

2 minutes ago, Dave Jones said:

100% its a bodged warm roof. If wind can lift it moisture certainly will be getting in.

 

The whole loft space once insulated under a grant from previous tenants owner.

So your probably right. 

Any ideas on the solution.

[ToughButterCup]

19 minutes ago, Limping2040 said:

...

Any ideas on the solution.

 

I'm really sorry: the answer is take it (the top membrane)  off and replace it. Pray the underlying (wooden / osb ) surface is worth saving

[Limping2040]

Just now, ToughButterCup said:

 

I'm really sorry: the answer is take it (the top membrane)  off and replace it. Pray the underlying (wooden / osb ) surface is worth saving

 

So is it a case of the membrane being no good? Or it just more tricky to do so? As it's only one corner in strong winds that lifts. 

Just try to get a clear picture so when I approach a roofer at some point I can verify what they are saying.

[ToughButterCup]

From the video evidence, I think the following is happening

• the whole top layer at least is being lifted by the wind
• I think the wind is bouncing over the top of the flat surface and causing a low pressure area which
• sucks the whole membrane upwards (Bernoulli Effect)

That shows the top layer (whatever it is) has not been bonded to the layer below - and (whatever it is) it should have been

 

The question is (since normally it isn't this windy so the membrane lies down under its own weight)  

• how much water ingress has there been below the top layer ?
• how much damage has there been to the layers below that layer?

That means some investigative work, and possibly a temporary repair  to make good the investigative work.

Then you need to do some legwork to find at least three good roofers. You must do the normal Due Diligence on each company, and then choose one to do the job.

 

The key issue is - what is the job?

Getting someone to specify that job accurately - and then someone else    to put it right is the only way to avoid the inevitable conflict of interest. There's a huge temptation to 'get someone in to sort it'  sharpish. Doing that immediately puts you on the back foot: once committed, how do you control costs.

 

Finding someone suitable to do the work is a job all on its own. BH is full of people telling us how hard it is to find tradesfolk. I'm going to have to wait six months for a decent sparky locally. And SWMBO is not happy. Thats the pressure. And it never stops.

[Limping2040]

2 hours ago, ToughButterCup said:

From the video evidence, I think the following is happening

• the whole top layer at least is being lifted by the wind
• I think the wind is bouncing over the top of the flat surface and causing a low pressure area which
• sucks the whole membrane upwards (Bernoulli Effect)

That shows the top layer (whatever it is) has not been bonded to the layer below - and (whatever it is) it should have been

 

The question is (since normally it isn't this windy so the membrane lies down under its own weight)  

• how much water ingress has there been below the top layer ?
• how much damage has there been to the layers below that layer?

That means some investigative work, and possibly a temporary repair  to make good the investigative work.

Then you need to do some legwork to find at least three good roofers. You must do the normal Due Diligence on each company, and then choose one to do the job.

 

The key issue is - what is the job?

Getting someone to specify that job accurately - and then someone else    to put it right is the only way to avoid the inevitable conflict of interest. There's a huge temptation to 'get someone in to sort it'  sharpish. Doing that immediately puts you on the back foot: once committed, how do you control costs.

 

Finding someone suitable to do the work is a job all on its own. BH is full of people telling us how hard it is to find tradesfolk. I'm going to have to wait six months for a decent sparky locally. And SWMBO is not happy. Thats the pressure. And it never stops.

Thanks.
Any explanation on how water would get past the membrane if solid throughout a piece without any breaks in that area, as from as much as I can see its' possibly one sheet? If its one solid sheet from end to end?
Or is the usual process to do sheets in sections.
Wouldn't I have had water come past the layers into the room by now?
There was a stone layer up there but water and wind has moved away from the lifting area as well as the sheet membrane moving it too now. As its sounded worse over this period because the winds been head on with it.
The storm coming suggests the windws coming in from the other end so I'm praying it doesn't make it worse as it should be on the gable end.
Owning property sucks.

Edited February 16, 2022 by Limping2040

[Temp]

1 hour ago, Limping2040 said:

Thanks.
Any explanation on how water would get past the membrane if solid throughout a piece without any breaks in that area, as from as much as I can see its' possibly one sheet? If its one solid sheet from end to end?
Or is the usual process to do sheets in sections.
Wouldn't I have had water come past the layers into the room by now?
There was a stone layer up there but water and wind has moved away from the lifting area as well as the sheet membrane moving it too now. As its sounded worse over this period because the winds been head on with it.
The storm coming suggests the windws coming in from the other end so I'm praying it doesn't make it worse as it should be on the gable end.
Owning property sucks.

 

If its moving it will eventually crack.

[Dave Jones]

try your home insurance, its storm damage ?

[ToughButterCup]

10 hours ago, Limping2040 said:

Any explanation on how water would get past the membrane ....

I could speculate,  but that won't help. Now's the time for evidence gathering.

 

Take loads of photos and post them here, and ask us concise questions. We will do our best to help. We're not experts . Just hard-bitten , (mostly) kind people. 

Good luck 

Ian 

[Limping2040]

I appreciate everyones replies.