Does this look right to you? How should roofing membrane be laid - Its leaking!

[ConcernedCustomer]

Hi 

Hope you can advise. We have an extension being built and the builders have put the roofing membrane on which is Powerlon SupaPerm SP100. However it is leaking in several places. We are led to believe that roofing membrane should be put on fairly tight on the battens but we looked at what they have done and it's all very saggy. Have attached photos.  

Worried that this is a terrible job. This is a general builder - not a roofer who has done this. Should this all be watertight now?

Have attached photos

[joe90]

2 minutes ago, ConcernedCustomer said:

This is a general builder - not a roofer who has done this.

He is not even a good general builder. Yes it’s a crap job

 

3 minutes ago, ConcernedCustomer said:

We are led to believe that roofing membrane should be put on fairly tight on the battens

Do you mean this membrane or membranes in general?. Some recommend sagging very slightly to allow any moisture to run down to the guttering but nothing like what he has done. I repeat, a crap job IMO.

[Big Jimbo]

Total crap. Roof battens are not even the same size. Sack him off. That is shocking.

[Kelvin]

That’s awful. Our entire pitched roof was covered like a snooker table and not a single drop of rain came in even in torrential rain. I did it with my joiner and neither of us are roofers or general builders. 
 

What’s the roof buildup underneath it?

Edited August 28, 2023 by Kelvin

[Jilly]

Gulp, I’m guessing you need help on how to handle this?

Is the rest of his work good? Has something happened? His usual roofer not available?
You’ll need to handle it sensitively or he might stomp off and leave you with a leaking roof and a half finished extension.

That might be a good thing if he’s not very good elsewhere. If it looks like you will suddenly need a new builder/ roofer, get speaking to friends for recommendations asap. If the rest of the job is ok, then this can be sorted out by a roofer quite easily, but you might need back up when you speak to him (sorry, am assuming it’s a bloke, lady builders are out there!). 
Depends how he reacts. If he walks, you might need to project manage the rest, which is doable, provided you are watertight. Another way round it might be to call Building Control and ask for an inspection. 

[twice round the block]

It's  not even a roofing membrane unless your using metal profile sheets on your roof, it's normally used as a vapour barrier on timber frame builds.

 

[ProDave]

11 hours ago, Big Jimbo said:

Total crap. Roof battens are not even the same size. Sack him off. That is shocking.

And they are not even the coloured ones that are coloured so that building control can easily see that they are treated.  No colour, they are probably not treated and building control could fail the job.

 

It needs ripping off and starting again.  Sorry.

[ConcernedCustomer]

Thanks for the replies. Yes we are having metal tiles - Metro tiles - I will get building control to come see it. Best way to deal with it. Yes we are shocked at the work. The walls are wonky too. I could cry - this is our all our life's savings going into this. 

[ProDave]

I would tell them to halt work until you have had building control look at it.  Post pictures of the wonky walls and point them out to building control.

 

Don't make any more payments to the builder until it has been resolved and you are happy with the work.

[ConcernedCustomer]

Well I contacted his boss last night who is actually a roofer. And guess what - this morning he walks in and says that his boss says the whole lot has to come off and redone. What a relief. We are going to get building control involved as well to inspect everything they do. Thanks for the advice everyone. They said they are going to use different membrane because it should not have leaked like that. I hope they pick the right one for the metro tiles. 

[BadgerBadger]

Well done! I've just membraned our roof, and you shouldn't really have any obvious leaks.

 

Keep an eye on the battens they're using too, they should be graded and marked.  The colour dye thing can be a bit misleading, but if you look at a bundle you should see the BS marking.  It's an easy thing for building control to spot check.

[Kelvin]

1 hour ago, ConcernedCustomer said:

Well I contacted his boss last night who is actually a roofer. And guess what - this morning he walks in and says that his boss says the whole lot has to come off and redone. What a relief. We are going to get building control involved as well to inspect everything they do. Thanks for the advice everyone. They said they are going to use different membrane because it should not have leaked like that. I hope they pick the right one for the metro tiles. 

Good stuff. Get onto whoever makes the tiles and ask them which membrane they use, require, recommend. Tell builder to use that one. 

[Temp]

17 hours ago, ConcernedCustomer said:

We are led to believe that roofing membrane should be put on fairly tight on the battens

 

No.

 

The membrane should drape/sag slightly between the rafters and not be tight under the battens. If you make it tight you risk dirt and pollen sealing the batten to the membrane and water pooling above the batten causing rot. Any water blown through tiles or slate should run down the membrane into the gutter passing under the batten.

 

That said I think yours is much slacker and more wrinkled than it should be.

 

4 hours ago, ConcernedCustomer said:

Well I contacted his boss last night who is actually a roofer. And guess what - this morning he walks in and says that his boss says the whole lot has to come off and redone. What a relief. We are going to get building control involved as well to inspect everything they do. Thanks for the advice everyone. They said they are going to use different membrane because it should not have leaked like that. I hope they pick the right one for the metro tiles. 

 

Good.

[Temp]

 

https://www.roofingsuperstore.co.uk/help-and-advice/project-guides/pitched-roofing/how-to-install-breathable-roof-membrane/

 

Ensure draping occurs

The breathable roof membrane should drape slightly between the timber rafters or counter battens, meaning there is a dip of around 10-15mm. Once you’ve checked that this is the case, add temporary clout nails to the top of the membrane – try to ensure they are above the line at which the second length of the membrane will overlap. When the tiles or slates are fitted they will provide a more secure fixing.

[makie]

18 hours ago, twice round the block said:

It's  not even a roofing membrane unless your using metal profile sheets on your roof, it's normally used as a vapour barrier on timber frame builds.

 

They are having metal installed, you can see it on the neighbors roof.