Roof Leak

Gravale

My bungalow was built in 1986 in Stillorgan. There has been water seeping in around the area of the chimney flashing and manifesting itself in the attic by dampness where the chimney blocks appear after entering the attic roof. I've had the original builder attempt a fix, I employed a subsequent 'firm' to try their hand, and finally I got another 'business' to make their attempt at the job. The rain still seeps in!!

You'll appreciate that after three failures by 'experts' I'm totally devoid of confidence in any tradesman's ability to deal with the matter and sceptical of an advertisements ("In the business 40 years") which look for my custom. I'm convinced, however, that the problem is a minor one if only someone took the time to thoroughly study what the cause of the problem is. I have no head for heights (even though it's a bungalow) but I'm certain that if I could get up there and re-apply the flashing properly that would solve the problem - which I have no intention of attempting! Could anyone recommend a genuinely experienced, knowledgeable, and reliable person to deal with this issue, please? Many thanks.

DiarmaidGNR

Can you post photos of the problem?

Gravale

If you were to get into the attic and look at the area where the blocks upon which the red-brick exterior chimney are laid (with damp-proof membrane where the bricks meet the blocks) you'd see a dark damp patch most of the way around and down the concrete blocks. No rain ever falls onto the ceiling below, but the sight of the rain seeping in from somewhere is depressing. When the day is better and brighter I'll add some pictures. It's so cold at the moment!!

DiarmaidGNR

Gravale wrote: »

If you were to get into the attic and look at the area where the blocks upon which the red-brick exterior chimney are laid (with damp-proof membrane where the bricks meet the blocks) you'd see a dark damp patch most of the way around and down the concrete blocks. No rain ever falls onto the ceiling below, but the sight of the rain seeping in from somewhere is depressing. When the day is better and brighter I'll add some pictures. It's so cold at the moment!!

That's your problem, the damp proof course should be at the same level as the lead flashing. The lead flashing is supposed to be a continuation of the damp proof course.

As shown here - http://www.ormonde.ie/images/detail-6.gif
Unless I am misunderstanding the problem, - Throw up some pictures!

Gravale

Thanks for that illustration. However, in the image the metal tray d.p.c. is at the top of the chimney whereas the d.p.c. I'm referring to is simply the 'plastic' membrane upon which the red-bricks were originally built on top of the concrete blocks in the attic.

I've just now taken some pictures and will post them as soon as I upload them to my computer.

Gravale

Pictures attached:
(click on 'zoom' in bottom r-hand corner when opened)

Gravale

I wonder would this be the answer to my problem? Perhaps the guidelines suggested here were not followed in my case? And if this is the answer can anyone recommend a suitable qualified and experienced person?

http://www.ormonde.ie/good-brickwork2.html

DiarmaidGNR

I can't recommend anybody, but if you go for someone like "mister X and sons - 40 years experience", be adamant that you will only accept mister x for the job, -you want someone with experience.

Personally I would just get some silicon and seal up the gaps (over-lapin gaps visible in the pictures etc) in the flashing as deep as I could (be liberal). It could fix the problem.

But to be on the safe side get a builder you know locally that won't rip you off.
In these recession times you get your moneys worth - so haggle!
A quick fix like I mentioned could cost from free up to maybe €40,
but if you want to go full hog and rebuild the chimney from the dpc up, - that'll cost a few hundred euro probably.
Ask around in your local area for a decent builder.

Gravale

Thanks, Diarmaid. I'll take your advice and look around locally for a reputable builder.

Happy New Year!

RKQ

It sounds very like a missing or damaged metal tray. However, I'm not sure why the problem has just presented itself in a house build in 1986?

Is any external lead flashing loose or missing?
Have you had a chimney fire recently?

I agree you need an experienced tradesman - roofer or blocklayer. In the mean time you could brush on Waterproof sealer - available in most builders merchants / DIY stores - €20 for 5 litre metal drum. Brick is porous and if its sealed or plastered then this should solve the problem.

BTW photo 005 shows the lead flashing on the side of the chimney, goes down below the ridge tile - allowing water to flow down side of chimney - is this causing your problem? The severe rain in November might highlight itself now. Whereas you may not have noticed it before.

Let us know how you get on.

mickdw

I would say you dont even have the required tray in the chimney. However as pointed out above, this house has been fine for many years so the problem may be fixable without knocking the external chimney to fit the metal tray.

So firstly I would inspect the chimney outside to see if all lead looks good.
Also check all brick joints & pointing.
Check the cap for cracks and reseal around the flue with flexible sealer.

Then if you still have a problem, this means the water is soaking in through the brickwork. The metal tray is the proper cure for this however you could try coating the bricks with a good quality clear waterproofer. If this stops the problem, you might be happy to just apply the waterproofer once a year instead of rebuilding the chimney

DiarmaidGNR

I agree, there seems to be no metal tray. It seems that there is just a normal plastic dpc in place of the metal one.- And I don't think that it would last long with the heat you get in a chimney stack.

trent1000

Id say the water could be coming through the cap if you mix up sand and cement 4:1 and put some waterproofer in with the mix then apply the mix to the top of the cap and ensure water cannot sit on the cap bulid it like a mountain the water runs off straight and does not sit on the cap and leak through any cracks in it. it is a cheap way to fix it if the tray lining is damaged of incorrectly finished.

Gravale

Thanks for your advice, gents.

The problem has been there from day 1. I've had the builder and two roofing concerns attempt a repair but all with minimal or no effect. They obviously couldn't be bothered to put much effort in and just wanted a quick buck. Hence my scepticism and lack of confidence in any "40 years in the business" and such-like concerns. I feel that they were simply addressing minor external issues and not dealing with either renewing or putting in sufficient flashing or putting a metal tray in. I'm useless when it comes to getting onto a roof, otherwise I'm certain that I'd have solved the problem myself years ago. The problem I feel can only be corrected by rebuilding the chimney properly as per the link I gave above. However, because of my past experiences with roofing people I'm unsure as to who might be qualified to do the work.

RKQ

Gravale wrote: »

However, because of my past experiences with roofing people I'm unsure as to who might be qualified to do the work.

A fully qualified Bricklayer is required.
Retained by referral or reputation. There are many experienced and compedent individuals out there. It won't take long to remove existing chimney to below roof tiles, install metal tray and rebuild chimney.

Gravale

Thanks, RQK. That's the approach I'll take.

RKQ

Gravale wrote: »

Thanks, RQK. That's the approach I'll take.

Delighted to be of some assistance, you are very welcome.
Let us know how you get on. Good luck.