How to determine the source of a roof leak

BrokenJetpack

So my 3 bed semi-d in Dublin 9 has an ongoing roof leak coming in to an upstairs bedroom that happens in heavy rain, maybe once or twice a year, but now I have a new leak in my hall since the recent heavy downpours. The carpet on the upstairs landing is dry though so it's hard to figure out where it came from (second pic shows the floor / landing area above where the leak happened). I went into the attic during the last downpour but I couldn't see any leaks. Having said that it's difficult to get in to some of the dark dingy corners as my attic isn't fully floored

Twice in the past number of years I paid companies to fix the problem. They both said "ya there was a loose tile and I fixed it so it should be sorted now etc." but it continued to happen. (Needless to say when I rang them back they didn't want to know about it).

It's pretty difficult to get someone to come when the leak is actually happening as it's always a day or two after when the rain has stopped, so is it necessary to be there during the leak or can roofing companies determine the source of a leak when it's not raining? How do roofers test if a leak is fixed? Is it possible to tell straight away or do I have to wait until the next heavy downpour to see if it's still happening?

If anyone has tips on how to determine the source of a leak or can recommend a good roofing company I'd appreciate it.. thanks in advance 👍️

kieran.

Could you post some pictures of the outside of the house?

Is there a light fitting in the ceiling above the downstairs leak?

BrokenJetpack

https://www.boards.ie/discussion/comment/121305334#Comment_121305334

I have a wooden ceiling in the hall and there are 2 spot lights, so not a light fitting as such.

I attached a couple of pics of the back corner of the attic that's roughly above the spot in the upstairs bedroom where the original leak is. There are signs of water ingress but I couldn't see any actual drips when I was there during the last heavy rain. Also attached some pics of the house, angles aren't great though so not sure if they help.

Alkers

Well there's definitely a hole in your roof felt there anyway which you should get fixed.

Often very hard to diagnose these things, especially over the internet!

youtheman

That hole in the felt 'rings a bell with me'. Damp patch appeared in the ceiling of my parents house (built in the 1970's). I knew there was no pipes near there, so I was very confused. Went up into the attic and I was right, no plumbing near by. But then I felt a breeze, and looked up to see a hole in the felt exactly like yours. Turned out there were several holes in the felt, which was very brittle to the touch. That happens with that tar based felt. When I turned off the light in the attic I could see daylight through some of the holes. Turns out in very windy conditions, the water can be blown under the tiles and through a hole in the damaged felt.

So as suggested earlier, you need to patch that felt hole (as a minimum). Might not be the root cause, but can't be doing you any good!.

GreeBo

You basically diagnose it by tracing the water backwards from where its appearing.

If you just go look at the roof it can be very hard to find as the water could be running along rafters, down trusses, across plasterboard etc.

How wet is the plasterboard above the wet floor?

Based on the amount of water on the floor the ceiling should be drenched and soft.

Usually water will make it way out of a spotlight hole or ceiling rose as its an easier route than soaking through the plasterboard.

If the plasterboard is totally soaked you are better off cutting it out and then at least you can investigate further.

10-10-20

It's in a very unusual spot though, that's what's interesting here as it appears to be downstairs and around 2m in from the original rear wall where the vent stack is for the bathroom. Hence I don't think it's coming from the main roof, but that main roof needs looking at alright as I see two areas where there appears to be ingress on the wood.

I'd wonder if the flashing around the vent stack is damaged and it's tracking inwards via the stack and then appearing from under the bathroom floor and into the hall.

Endoscope camera into a small hole cut into the ceiling under the toilet might tell you.

phormium

I am presently dealing with 2 leaks in my roof! So annoying! Small wet patch on two bedroom ceilings in dormer but the leaks are in the attic sides. Anyway to find them, and my internal roof looks just like yours with the perished felt and all, I have laid cardboard down roughly above where the leak is showing downstairs. I only get the leak in very bad rain like some of biblical stuff we've had lately. Anyway after any prolonged bit of rain I go in and have a look and I can see the wet blotches on the cardboard which has shown me where one leak is anyway, while I can see where it's dripping from the patch I actually think in my case it's getting in up further around a velux window.

I'm giving up trying to get anyone to fix until the spring but then again the leaks are not bad and I have put a basin under the one where it drips so at least it's not getting as far as the plasterboard and I can just keep an eye on it.

The second leak while it made a bigger stain on the ceiling shows no drops on the cardboard so again I think mine is another velux issue and travelling down along the upright timber forming attic dormer side wall, that said it hasn't happened since I put down the cardboard.

Yours could be travelling along many routes but if you can try laying down cardboard and checking regularly after rain to see if you can see any obvious drops coming through felt holes, often felt can be worn thin and water getting through without an obvious hole, I have many holes in mine which are bone dry but the bit it's getting in through is not obviously holed at all just worn thin. I think I can actually patch the worn bit due to where it is as I can tuck in a bit of waterproof stuff under next join in felt which will guide the water down and out again but ultimately I think I need to replace my velux windows.

Mr321

Could be the ridge tiles that's the problem or the flashing at the chimney. I'm leaning towards the ridge tiles and the mortar around them

jack of all

A pair of binoculars in the right hands (with experienced eyes!) can be useful to carry out a visual inspection of the roof, especially good for checking ridge lines etc. If the issue is so intermittent it may be due to heavy wind driven rain and the direct source may be some distance from where it's seen.

BrokenJetpack

Thanks for all the replies and ideas, much appreciated. I had a guy from a roofing company look at both leaks during the week. He said the new downstairs leak in the hall doesn't seem to be coming from the roof, and it could have been a one off from the bathroom upstairs, even though there was no sign of water or dampness on the carpet or landing above the hall. So basically keep an eye on it and investigate if it happens again.

For the older ongoing leak he looked in the attic and basically said the felt is worn in places on the back part of the roof and while he could do a patch up job for 500 euro, he wouldn't guarantee that it was fixed, and he wouldn't stand over it. He actually said that he would get it in writing from me that I couldn't call him back to fix it if the leak happened again after a few months. So his proposal was to replace the felt on the back part of the roof at a cost of 5.5k euro or do the entire roof i.e. front back and side for 10k 😮

So now I'm not sure what to do. If I was going to spend that much money then I'd probably do a bigger job and put in a couple of velux windows and a proper ceiling. I had some vague notions of doing something like this in the near future, not an attic conversion as such but just a storage space.. put down a proper floor and insulate the ceiling etc.

As an aside I had no idea of how many roofing companies there are in Dublin until I googled them.. there are literally dozens and they all do the same thing. How does a person pick a good one? The company I called appeared on a google search and is also on Facebook, and they seem to have good reviews, but 5.5k for patching up a bit of felt seems high and I'd like to get more opinions. Some companies have a lot of Facebook reviews but when you look into them they're fake.. generic messages from random profiles that aren't even in Ireland let alone Dublin. (I'm pretty sure there are web development companies you can pay to create fake reviews for you).

If anyone can recommend a good roofing company I'd appreciate it. Also if anyone floored their attic or put in a a proper ceiling, maybe with velux windows as well, I'd love to know how it turned out and a ball park cost.

Thanks in advance 👍️

Oscar_Madison

Be really careful picking roofing companies- I had a small roof leak about 6 years ago - when you Google, you’ll get the same companies saying they can do Dublin as well as Cork or Wicklow - they all seem to have the same number - some clever websites or Google set up or something -none of them looked legit

Try your insurance company in the first instance or neighbours who have had reliable work done- I did get someone local eventually (sorry I’m nowhere near your area) - but it took time and careful consideration/ as you’ve illustrated it’s a big financial commitment

I was looking at your roof to see if you might have had the same problem I had (worn valley flashing) but doesn’t look like you have any .

My leak came into the front bedroom ceiling so very easy to identify - as others have said you might have two leaks- one roof and one internal but Jesus do some investigative work now- you’ve a nice house so you don’t want all that hard work undone - waters a bitch so it is 😀- best of luck

Juwwi

OP Im going to send you a PM of a very good roofer ,, be very careful ringing random roofers ,, lots of cowboys out there

DC999

+1 to insurance company. Call them and explain you’ve a leak and ask what they suggest and if they have a panel of approved or recommended providers. Assuming they do have a list of providers, you've some form of recourse if it leaks again. As in the insurance company have more clout than you as an individual.

I got a leak fixed on a flat roof years ago but only realised later I should have gone the insurance route. Not sure if they still do it, but my insurance company asked if I wanted to repay the amount back (it was for another claim) and then my no claims bonus would be unaffected. 

GreeBo

OP I wouldnt be spending any money to fix a roof leak that appears to have nothing to do with your roof.

Also "a one off bathroom leak" isnt a thing, you either have a leak in your bathroom or you dont, leaks dont fix themselves.

You need to open up the ceiling where it is wet to trace the leak, it'll cost bugger all to get that patched and painted and its the (start of) the only way to source the leak.

The longer you leave doing this the harder it will be as things will dry and you wont know if the staining is from this leak or where something got wet during construction etc.

Toby22

Hi, ask one of the roofing supply companies for their registered contractors. All companies that supply materials be it tiles, floors, construction materials have a list of their approved contractors