Help finding leak into old chimney on a flat roof

[lee666]

Hi all,

I'm after some assistance in trying to find the cause of water coming into my kitchen ceiling via an old unused chimney that is on the back of the house.

We have a single storey extension which houses the kitchen and bathroom which the old chimney goes into, in the corner of kitchen.

Before we had our kitchen done 2 years ago, this old chimney came partially into the kitchen where the bottom was plaster board and then plastered, and it started leaking a year or 2 before.

When we had the kitchen done the bit that came into the kitchen was removed into the ceiling and then the hole was boarded up, at the same time we had the felt roof replaced.

The winter after we had the kitchen and roof done water was coming into the kitchen in the same place, however it only happens with heavy, continuous driving rain.

We called the roofing company out who put lead flashing on the side of the old stack by the roof slope and also retouched the felt around the bottom.

This seemed to have sorted the problem at the time as for the last year it hasn't leaked, until now. A month or so ago I noticed faint brown marks coming through the paint in the corner, fearing the worst I contacted someone who deals with chimneys to get the top of it repointed as a precaution.

Over this Xmas period water has leaked twice into the kitchen. The first time was Christmas day night when we had heavy driving rain, and again boxing day night when we had some snow and driving rain.

Just for information, it rained constantly and not too heavy boxing day afternoon/evening and the corner in question was dry as a bone with no water coming in.

Today the chimney guy came out to have another look and he believes it is roofing related as opposed to the chimney. I've attached a variety of pictures for assistance, and as you can see at the bottom of the stack is a lip just above the roof, this is where he thinks the water is coming in.

There appears to only be 1 layer of felt around the brick work, I got up on the roof with him and also noticed in 1 corner that a piece of felt has seemingly come unstuck leaving a gap that water could get behind. He also said that there are way too many joins in the felt around this area, and that the roof felt in general has been laid wrong.

My questions are as follows:

1) is 1 piece of felt going to get waterlogged in heavy continuous rain?

2) could water be seeping in via the amount of joins in the felt around that area?

3) seeing as it did it before the roof was replaced could it be coming in somewhere else?

4) my neighbour has some flashing on the lip on their side, should mine have the same?

The chap who came out suggested getting the roofing company out to redo the area around the bottom as it should be covered. If I do this, would it be unreasonable to ask for the whole roof to be redone if the general consensus is that it's been laid wrong in the first place?

I've spoken to my neighbours and they haven't had any problems with water leaks in their kitchen, and I've checked the back bedroom of our house and there are no signs of water. I do know that my neighbour has water coming in their back bedroom by their old stack, but could this even work it's way to my kitchen and not theirs?

Sorry for the long post but wanted to give as much info as possible as it's starting to get annoying. Thanks!

 

[bobasd]

your roof felt has been wrongly laid. the felt should be laid across not longways. the the detail at the base of the chimney breast an roof, and the upstand against the house wall look shoddy an failing.

the lead flashing on the shared stack an the neighbours stack is dead rough an wrong and could be leaking.

Theres cracks to the chimney breast render and rusty corner bead. galv angle bead is wrong it should have been plastic or ss.
if your chimney breast has been removed below, what is supporting it if the neighbours half has also been removed? you an the neighbour could go in for removing the whole chimney breast and stack but it wont be cheap making good the flat roofs an the main roof.

No matter,your flat roof detaling is in need of a revisit by the original roofer. wasting money pointing and doing bits here an there wont work.

 

[lee666]

your roof felt has been wrongly laid. the felt should be laid across not longways. the the detail at the base of the chimney breast an roof, and the upstand against the house wall look shoddy an failing.

the lead flashing on the shared stack an the neighbours stack is dead rough an wrong and could be leaking.

Theres cracks to the chimney breast render and rusty corner bead. galv angle bead is wrong it should have been plastic or ss.
if your chimney breast has been removed below, what is supporting it if the neighbours half has also been removed? you an the neighbour could go in for removing the whole chimney breast and stack but it wont be cheap making good the flat roofs an the main roof.

No matter,your flat roof detaling is in need of a revisit by the original roofer. wasting money pointing and doing bits here an there wont work.

Thank you for your reply and apologies in not replying sooner myself.

Just a bit of an update as we've had a fair bit of rain lately. Until today it hasn't leaked as the rain hasn't been too heavy or driving. Tonight though is another matter. It was pouring down earlier with very heavy wind driving it at an angle. The water was coming in more than it ever has and when the wind really gusted the drips got worse. The corner in the kitchen ceiling was already soaked and knackered so I made a small hole to investigate.

The inside walls of the chimney that I could feel were dry. There is some insulation wool inside to stop heat being lost into the void and that too was dry which I think can rule out my neighbours flashing and the water running down the inside.

The worse of the water dripping down was on our side I'd say about a foot or so along from where the base is.

In all honesty I would love to remove the stack but the neighbour wouldn't be able to afford it and I don't think it could be done under the buildings insurance to help her.

How would I best approach the original roofing company about this as it's been around 18 months since it was done. I presume it's covered under the guarantee the gave me, would need to dig the paperwork out for the length but it was around 20 years I think.

 

[catlad]

Ask them to come round and take a look at the
water ingress and take it from there.

 

[bobasd]

i agree.
in the meantime why not put up some photos of inside the kitchen.

 

[lee666]

thank you for the replies chaps. I have actually now found where the leak is coming from. When I got home from work earlier i got my garden hose, and hanging out of the bedroom window I concentrated the spray in several areas where I suspected it was getting in. After a bit of trial and error I have now narrowed it down to the corner where the chimney breast and the back wall of the house meet. Within a few seconds of me aiming the water flow there the water came running down into the kitchen.

This makes sense as When I was on the roof the other day I noticed a patch of felt that looked like it had come unstuck and was creating a bulge with a gap behind and I am 90% certain it was in the same place. Unfortunately I don't have a ladder big enough to get back up there and the other roofer is unfortunately on holiday now, as I want to double check and also get photos before I speak to the company that did the roof. When I was up there I also noticed that one of the boards moved when walked on, which I'm pretty sure it shouldn't be doing so I also want bring this up when I contact them.

I have spoken to the legal services that I have with my home insurance and even though I was a 15 year warranty they said i'm covered under a consumer act, and that the company would be liable to repair the damage caused by the water ingress.

 

[lee666]

Just a bit of an update: Managed to get a ladder so I could get on the roof as I wanted to check it myself, and take photos if needed, before I got in contact with the roofing company. Once I got up there it became clear what the problem was. In the corner where I sprayed the water there was a gap in the felt which had bobbled out. Also, the felt around the base of the chimney stack was unstuck next to the bobble and the felt along half of the back wall was unstuck. On the elevated ridge on 1 side to channel the rain water a small part of felt also had a gap, and on closer inspection there is a join where water can pool which is against the flow of rainwater.

I rung the roofing company after getting photos and a video of all of the above and they are coming Monday morning, I explained everything I found and also that due to this my kitchen had suffered damage from the water which would need to be fixed. Back at the start of 2016 I had them come out due to water coming in, and that's when they put the flashing at the top where the stack met the main roof, however I assume that part of the felt had failed then to let water in and has since gotten worse over the last 2 and a half years.

Given that this has potentially been letting water in for 2 years or so, would I be right to ask that they replace the boards underneath? I'm guessing that water has been coming in via the failed felt during this time but hasn't been enough, until recently, to leak all the way through so I do wonder if the boards and ceiling have been soaking up what has come in.

So, my questions are:

1) Should they have chased the felt into the mortar to stop this from happening?
2) If so can I request that this be done?
3) Can I request that the boards in the affected area be replaced?
4) If they agree to replacing the boards can I assume that this would mean the whole roof would have to be redone?

Sorry for the long post but just want to be armed with everything ready for monday as I want it resolved properly so it doesn't happen in the future.

Thanks