Flat Roof Leak - Help Please

[CatmanV2]

I hope that wire isn't live

I was thinking just that!
C

 

[rossyl]

Here is a video of the inside of the ceiling.

The camera goes up facing the directly in front of where the leak is (unfortunately with a joist in the way). I then do a pretty slow 360 view.

I think it looks pretty dry. Note that there are no other damp spots on the ceiling.

 

[Oneball]

I’d guess the damp spot is where it is on the ceiling because of the join in the boards above which isn’t very helpful as the leak could be anywhere.

 

[CatmanV2]

You appear to have some alien technology in your roof void....

C

 

[rossyl]

Drilled another hole. Found the problem. Video on the way...

How do you make a chimney cap completely water tight?

 

[rossyl]

Drilled a hole directly where the leak was.

The camera is facing directly upwards to where the leak is coming from. You can see the inside of a chimney and the chimney cap at the top. You can also see the wood holding up the chimney.

EDIT: The water is dripping of the flashing you can see which seems to be towards the bottom of the chimney - which is why I always felt the dripping had some "force" behind it - as it was dropping from height.

Where the water is coming from that is dripping onto the flashing around the chimney - that is a question mark.

The torch is in the way a bit

How do I make the chimney cap completely water tight?

This has been stressful, expensive and annoying (the drip is in our bedroom and was loud enough to wake me up) - so I am glad I have found potentially the problem, now to just fix it.

 

[Scaf]

Is the chimney in use ie: boiler flue : fire : log burner?

 

[rossyl]

In green I've put an arrow to the base of the chimney pot.

Above that is some flashing. Which I have put some red lines on.

It is the edge of that flashing (near the red lines) where it is dripping from.

Given where it dripping from - I am guessing it is coming from:

• the top of the chimney stack around the edge of the chimney pot (though i have put a lot of Cromapol here)
• somewhere else on the top of the chimney
• or water is getting inside the cap and then running down the inside of the chimney? is that possible?

It doesn't need sideways rain to start dripping, a reasonable downpour will do it. Light rain will not cause it to drip.

Any ideas appreciated as to how I now stop this leak.

Thanks

 

[rossyl]

Is the chimney in use ie: boiler flue : fire : log burner?

Appreciate it is hard to understand, but that is directly above the ceiling in my bedroom. So it is absolutely not in use.

 

[2b1ask1]

Ross, if there is nothing using the chimney pots because the stacks are removed, I would say you can remove them completely from the top, get the concrete pad cut with a disk cutter right across the centreline of the chimney on the roof so you can break it out back to bricks your side. then get it slated by a roofer with genuine slates or stainless steel sheet and cemented down and then fully sealed over the top to cover all the bodged felt up there. Also I would look to replace those coping stones on the wall with ones wide enough to get the drip over the felt for you and next door, probably 50-75mm wider. In your video you can see the pots are supported on slate, the water is making its way to them and then dripping in the old chimney. Of course in the old days this wasn't a problem because we used the chimneys to keep the houses warm!

 

[rossyl]

Thanks Newton.

I'm going easy option first. I've currently got "Pepperpot" chimney caps. Apparently these can cause water to come down the inside of the chimney.

I'll therefore remove the cap and replace it with a C-Cap that does not allow water to down the chimney.

This was a great resource: https://www.fixmyroof.co.uk/videos-and-guides/chimneys/chimney-capping

If it does not fix it then we'll look at works to the chimney pots/chimney itself.

 

[Marti]

Hi

We have a flat roof at the very top of our house in a loft conversion. It is torched on felt.

I'm pretty sure somewhere around the chimney breast, where the flat roof meets the chimney breast, or on top of the chimney breast, is a leak.
It is leaking onto the plaster board ceiling, not much water, but enough to be annoying.

We've called out
- a specialist roof repairer, who said he was going to seal the area, then coronavirus happened

- a roofer, he seemed alright, he burned felt on to the area that he said wasn't properly done. It still leaked, he came back and covered it in cromapol.

After the second time he came, and covered it in cromapol, the leak did lessen in terms of the amount and frequency of the dripping leak.

So I went up there and smothered it in cromapol. Covering a wider area.

But... You guessed it... It is still leaking

I'm at my wits end, as I want it fixed, but I don't want to keep paying for someone to just have a go.

I found websites of specialist who find leaks. This sounds expensive, is it?

Also, will a leak detection specialist actually find the leak?

Roof Leak Detection - UK Leak Detection

UK leak detection is second to none in roof and balconied leak detection. We are able to identify the leak location or penetration points to surrounding structures of your flat roof or balcony, by using the latest leak detection equipment and techniques, including… Wet testing method: First...

www.ukleakdetection.co.uk

Hoping we might have some roofers on the forum.


EDIT 1

This is how the roof originally looked, we have been told (by you guys) that's it's 'Join City' - with lots of joins and insufficient flashing.

View attachment 74065


EDIT 2

We had a roofer who "burned on" all the joints around the chimney. The leak still kept coming.
Roofer's second attempt was to cover it in Roofing Acrylic Paint. It slowed the Leak, but did not stop it.

We then did a second coat of Cromapol, acrylic roofing paint.

You can see the whole chimney is covered in Cromapol.
The bit in front of the chimney is covered in Crompaol.
A bit either side of the chimney is covered in Cromapol.


ADVICE PLEASE:

Should I
1. Try and get someone to add flashings, or has that ship sailed due to the Cromapol.

2. Go up there and cover more area in Cromapol - if so where?
I can see areas where water is pooling. I an see joins on the wall that i could maybe cover. What do you think?

This leak is really really annoying - so advice is much appreciated. Thanks

I would be grateful for opinions:


Here is what it looks like now.
Here is what it looks like now, took this today (using a GoPro on a stick) an hour after it rained

View attachment 74066

View attachment 74067



Thanks

God that’s bad very bad.

 

[allandwf]

Glad you found it. Tape heavy polythene bags over them for a couple of weeks, as long as it rains, to confirm, if so just have them removed as long as not used for ventilation. Either that have a couple of Chinese hats fitted.

 

[outrun]

We had a similar thing with unused chimneys but they looked nice so we took them off, cemented a nice slab across the top, making sure to seal well and fitted the chimneys back onto the slab. Raised the depth of the slab, maybe an ince, but otherwise, looks the same.

 

[sionie1]

At least you’ve found the source!