New Roof concerns

[Flat-Bumps]

Hello,

Recently I had a complete reroof. No membrane natural slates roof replaced with non-permeable membrane and manmade slates.

After the roof was complete I went into the loft and I expected to see the membrane covering all the internal roof space.
The pics show something sticking below the membrane. This doesn't make sense to me. So hoping someone here can tell me what this about.

Thanks.

 

[Wayners]

Looks like the wood is to nail last few rows down... Maybe.
I think that gap is a mistake.
Maybe.

Watch this video as shows some information that will help you.

 

[Alastairreid]

Looks like an old slate! Should pull out.

 

[Flat-Bumps]

Thank you for your responses.

I watched the YouTube video and could see the timbers at the bottom of the roof.

I then took another look at my internal roof pics and realised that my pics 1+2 are around a chimney stack (which was re-leaded).

In my pic 3, between the purling and the timbers are mucky bricks of the chimney stack.

After searching for roof leading I understand that at a chimney stack / roof junction, there are :

1 back box gutter
` 2 soakers
3 step flashing
4 front apron

Questions;

Do any of these leads sit below the membrane ?
Do the membrane cuts / joins look normal for a chimney area or is it some kind of patch-up?

Thanks.

 

[noseall]

Thank you for your responses.

I watched the YouTube video and could see the timbers at the bottom of the roof.

I then took another look at my internal roof pics and realised that my pics 1+2 are around a chimney stack (which was re-leaded).

In my pic 3, between the purling and the timbers are mucky bricks of the chimney stack.

After searching for roof leading I understand that at a chimney stack / roof junction, there are :

1 back box gutter
` 2 soakers
3 step flashing
4 front apron

Questions;

Do any of these leads sit below the membrane ?
Do the membrane cuts / joins look normal for a chimney area or is it some kind of patch-up?

Thanks.

Yes. The back gutter can end up visible (from inside), depending how that have done the membrane.

 

[ree]

OP,
No problem but I'm afraid your understanding is a little confused.

None of the lead flashings should be visible from below.
Neither should battens, tiles/slates or nails.
The membrane runs to the stack on all sides, and then rises up the brickwork in an upstand.
The upstand height can vary but the membrane should go up as high as possible behind the cover flashing.
Fixing the membrane correctly below the back gutter is a detail that many who attempt to install back gutters get wrong.

FWIW: the key to sound back gutters is the little prep carpentry that goes into constructing a platform for the lead back gutter.

 

[noseall]

None of the lead flashings should be visible from below.

With regards to the BG (back gutter) - that depends how far up the roof the BG goes in relation to the membrane lap.

 

[ree]

Poster # 7,
I think that I understand what you are describing - so yes, you are right if you are saying the the membrane can be brought part-way down the "sloping upstand" on top of the lead.
I was wrong to make a blanket statement about the arrangement of the membrane just because thats how I like to do it. So I accept your correction & apologise.

 

[Flat-Bumps]

Yes. The back gutter can end up visible (from inside), depending how that have done the membrane.

OK.
After querying this are with the roofing company I was informed that it was lead.
I put a magnet on that object and it did not stick. So I guess lead is not magnetic ?
So, if it is the lead back gutter; would not go all the way across the rear of the chimney stack ?

 

[Flat-Bumps]

OP,
No problem but I'm afraid your understanding is a little confused.

None of the lead flashings should be visible from below.
Neither should battens, tiles/slates or nails.
The membrane runs to the stack on all sides, and then rises up the brickwork in an upstand.
The upstand height can vary but the membrane should go up as high as possible behind the cover flashing.
Fixing the membrane correctly below the back gutter is a detail that many who attempt to install back gutters get wrong.

FWIW: the key to sound back gutters is the little prep carpentry that goes into constructing a platform for the lead back gutter.

I am learning this a little, as there is not too much on YT about back gutter (in full).

 

[Flat-Bumps]

This Video is very good but I wonder how many UK roofers do it this way, or think it is not necessary.

 

[Flat-Bumps]

This video looks really complicated.
Unfortunately, after that chap constructed the back gutter he didn't offer it up to roof mock-up

 

[Flat-Bumps]

Cannot find any videos which show back gutter in full ie. lead, underlay, slate.


Oops, I didn't realise adding the link by text, added the actual video link.

 

[Alastairreid]

The guy in the 1st video was a regular poster on here at one time. Justlead. Lovely guy.

 

[Flat-Bumps]

Thank you for the responses.

I thought, I (previously) learned that roofs rain defence was :-

1 slate,
2 membrane (above),
3 lead back gutter,
4 membrane (below)

So, that the back gutter is sandwiched by two layers of membrane and not visible within the loft sapce.

I think I now understand that perhaps, there is NO set way to do the back gutter.

Maybe though from these pics you can explain how the roofers have done it ?