Repairing leaks in a roof valley

Det Somerset

To start with, I'm completely clueless with regards this topic and will likely be ignorant to a lot of the terminology I should be using to describe things, so please forgive me if I come across as a moron

I could write an essay on the history of the problem, but ultimately I have a valley between a hip roof and a vertical wall which has leaks. The builders are no longer part of this equation and my father in law and I are attempting to see if we can resolve the issue ourselves before contacting a professional. After working on it over the weekend I can best describe the issue as follows.

The valley is made up of about 5 sections of hard (fibre glass?) material which is supposed to let the water flow down to one end where there is a drain pipe. If the valley was angled down to the drain pipe end enough, the current construction may be fine, however as it is closer to horizontal than ideal, water gathers along the valley and seems to be seeping back under the previous overlapped section. With a solid flow of water, the dripping in the room underneath is significant. What we tried to do was to cover the overlap 'join' with what I believe is called flashing tape (tar on one side, aluminium on the other) and this did seem to improve the situation as the dripping seemed to lessen notably but it wasn't a definitive solution. I can show a picture of the type of job we did as follows ...



You can see that the water is supposed to flow away to the right and mostly it does, but also in each section it pools and seeps back due to a small ridge at each overlapping section. We believe that's where it gets back in under the previous section causing the leak. My primary question is how should we be sealing these sections for a long term resolution as cheaply and easily as possible?

As a secondary question, at the very 'top' end of the valley there appears to be a notable gap that is bigger than something we should be covering with any kind of tape. I am pointing to it with a red arrow here ...



That material is solid so we cannot push it down. The gap is over an inch wide and half an inch high. I believe we need to fill this with something and then maybe try and seal it as with the other sections. Again, any advice on this would be appreciated.

Thanks in advance ...

Det Somerset

Due to the lack of replies despite the forum being active, I think I should have posted this query to the Construction & Planning forum. Is there a way to get this thread moved, or should I just go repost the same query over there?

Thanks

wait4me

Mods should get to this for you in a while - don't double post!

wait4me

It also might be worth posting a photograph showing the hip roof from a distance - it will give a better idea of slopes etc.

Det Somerset

wait4me wrote: »

Mods should get to this for you in a while - don't double post!

That's what I was thinking, thanks

Det Somerset

wait4me wrote: »

It also might be worth posting a photograph showing the hip roof from a distance - it will give a better idea of slopes etc.

I might be oblivious to something clearly important here, but I'm not sure how that would help? The leaks are in the valley so how does seeing the hip roof itself impact things?

wait4me

I'll leave that to the experts. Your pics didn't explain the problem to me - but I'm not a roof person.

Bonzo Delaney

On a "flat " valley like yours with the lead over laped there should be at least a 1:6 fall about 10 degrees if not more.Other wise the water will just pool at the joints and soak back in behind its self. Did it always leak or only started recently. Sometimes if flat valleys aren't kept spottlesly clean moss builds up and holds the water back creating leaks also.
A proper solution would be to strip it off re board it and fibreglass the valleys. Or strip off raise the fall and re lead depending on the length possibly step the valley.
I'll probably be shot for saying this but a temporary solution and I mean temporary would be to clean the valley down fully dry off any damp spots with a towel and hair dryer / heat gun peel back the lead at the joints dry the lead and seal the full lap of the joint with tec 7 or similar high quality sealant.Then place the over lap lead back down over. Giving it a gentle tap down back in to shape with a lath and hammer of lead beater. That should buy you some time.

Det Somerset

Thanks Bonzo,

At this point I'm information gathering and I will take on board your advice gratefully. I'd also welcome additional opinions if there are any.

Short version, this has always been leaking. We are just lucky the room below is an unfinished concrete shell so no interior damage is being caused, although we accept that a leak like this could cause structural damage over time.

Bonzo Delaney

From what i can gather from your reply is that unfortunately for you this method of valley construction was never going to work. Either the material (lead) is not suitable for the slope. Or the slope isn't high enough for the lead.
Personally if it was mine I'd strip out the lead and the first row of tiles
Check the substrate is in good condion re clad in ply or osb
Then fibre glass the valley
Then the tiles sit back over the fiber glass.
I find the fibre glass is great for sealing awkward angles and areas and if the water pools on a level area it's still not a problem.
Hope this helps and you get sorted.

Det Somerset

Thanks again, Bonzo

Short version of the story, builders attempted fibreglass valley but leaks existed. Couldn't find/resolve leaking no matter what they did. Attempted to cover it with the solution you see in the picture which you suggest are sheets of lead ( and I expect you are right ) placed in an overlapping fashion across the valley. Water is still getting in under the overlap as the slope is not consistent due to the ridges created at the overlap. Builders started to become more and more difficult and relations broke down. There is still money owed to them but they seem to have given up and are content to take the loss and it would suit us to have nothing further to do with them.

I was hoping that myself and my father in law could finish the job ourselves if we could find a way to permanently seal the overlap areas. Based on what you are saying, any attempt to do so would be a short term solution, so we'll likely need to get another professional back to do the job properly.

Calahonda52

Det Somerset wrote: »

I might be oblivious to something clearly important here, but I'm not sure how that would help? The leaks are in the valley so how does seeing the hip roof itself impact things?

This reluctance/refusal is disappointing to say the least.
The last time i looked, the good folk here give of their time and expertise freely and you can't be orsed to throw up a few pictures that will allow a better input.
I hope it keeps fine for you.:mad:

Det Somerset

Calahonda52 wrote: »

This reluctance/refusal is disappointing to say the least.
The last time i looked, the good folk here give of their time and expertise freely and you can't be orsed to throw up a few pictures that will allow a better input.
I hope it keeps fine for you.:mad:

What's your problem?

The guy who mentioned it admitted roofs weren't his thing but said he thought it 'might' help someone else. I never said I couldn't/wouldn't or otherwise put up another picture. I'm on here respectfully looking for advice but also looking to better understand my situation. I politely queried why he wanted to see that picture as I don't understand how it would help any assessment if the issue is with the valley not the roof. Nobody has since requested that particular picture nor given an explanation as to why they would.

I'm not even going to bother apologising on the chance my earlier response was inconsiderate as I'm pretty sure you are the only one that is 'orsed' about it.

Bonzo Delaney

There's no reason why fibreglass would not of worked there
I can't figure that one out at all
Maybe it just wasn't done right
Looks straight forward and simple enough
Maybe a few more pics of the whole area might give a better idea but it looks like a common enough detail of the end of a sloping roof butting up against a wall forming a back gutter usually finished in a stepped lead back gutter or fibreglass or epdm even torch on felt done properly would of worked. Looks like for a permanent job and piece of mind find someone who is recommended professionally it's not a diy job

Det Somerset

Bonzo Delaney wrote: »

There's no reason why fibreglass would not of worked there
I can't figure that one out at all
Maybe it just wasn't done right

Nail on the head, methinks!

I'll see if I can take more pictures at the weekend just in case that gives a different perspective, but I'm fairly resigned to the fact that it's not a DIY job based on your feedback.

Det Somerset

Sorry for the delay in coming back. It's a little awkward getting up to the roof. I don't know if these help any further analysis but this is about the only other angle I can get.







The question I would ask is, what would the ballpark figure be to hire a professional to perform a long term solution here? I don't have a lot of cash currently so anything over 1000 I couldn't possibly afford and we'd have to put it off till next year, however closer to the 500 mark is something we could afford to get done soon.

Thanks again for the feedback and advice here

Bonzo Delaney

I know its of no use to you but that's shocking rough.
I'll have a look at a rough est later when I've time.
If I remember did you say orignaly there's fibre glass underneath all that lead maybe a photo of the under side if possible would help a lot.
You might claw some of the cost back if it was refiberglassed you could sell the left over lead to a scrap merchant.

wait4me

Those pics really gives us the scope of your problem. I'm sure that somebody will come to your aid!

Det Somerset

Thanks to you both.

Here's as much extra detail as I can provide, but keep in mind I may be inaccurate with some of the following due to lacking knowledge in the construction area ...

This was part of a major refurbishment. The roof was originally flat and replaced with the (hip?) roof you see above. Underneath the room is an unfinished concrete shell as we ran out of money on the project and because of this the leak was never noticed after we had moved in. The leak was noticeable all the way across the wall underneath with significant dripping in a number of places.

The engineer's original spec was for a Fibreglass valley and that was apparently what they put in (I've never seen it personally). The first attempt to resolve was to re apply the existing fibreglass valley (?), something about some part of the process potentially not sealing properly if it didn't dry in time the first time(sorry for being so vague). This failed to change anything.

The next effort was some sort of liquid sealant was applied. My understanding is that this would follow the path the water would take before hardening and sealing the leak. This didn't resolve the issue but it did seem to improve it and the leak was now only coming through below on one half of the wall, not the whole way as before. They tried reapplying that sealant but there was no further progress.

That worker then left the company and they sent someone else to take over. I believe this worker put the lead sheets down at this point and left convinced the problem was addressed but the leak remained. I believe there seemed to be further improvement in the room below but still not enough.

When they came back, they claimed that the leak was not in the valley as they flooded it manually and the leak wasn't coming through (I was at work so I can't verify). They claimed that the issue was with the vertical wall which didn't have felt under the caps and so the water must be leaking through that and under the valley. They said they could resolve this (you can see the work in the pictures above) and we were going to be charged extra for that as it was not part of the original build. However there was no improvement, and if anything it seemed that things were a little worse in the room below (although still confined to half the wall)

They started to avoid our attempts to contact and to be honest without going into details, I had had my fill of them so I'm happier leaving them out of it going forward. We have a small amount of money we would have paid them if they fixed the issue and I'd be happier to give that to someone else if I can't fix it myself. As I've said, I now believe I've proven that the leak is in the valley itself (despite what they told us) so that's what I'm now trying to address.

Regarding a photo of the underside of the lead, I don't know how I'd get that without pulling off one of the lead sheets which would surely make the issue worse as I wouldn't be able to suitably repair what I did? If I'm missing some opportunity here, please let me know and I'll do my best to get the picture requested.

Thanks again. I'm based in Co. Cork if that makes a difference for assessing potential cost.

Bonzo Delaney

I should of been clearer " underside " I meant inside the building if it's not slabed and still a concrete shell.

db

Is it possible that the water is wicking up the roof felt and dripping down from that? I had a minor problem where water was dripping down the outside wall under the soffit. When I looked I saw that a small piece of felt was dipping into the gutter and after I cut it back my problem with the dripping water was fixed.

Det Somerset

db wrote: »

Is it possible that the water is wicking up the roof felt and dripping down from that? I had a minor problem where water was dripping down the outside wall under the soffit. When I looked I saw that a small piece of felt was dipping into the gutter and after I cut it back my problem with the dripping water was fixed.

I understand what you are saying but wouldn't that result in a very slow drip? I'll show some pictures soon where you can see that the water that has getting through is significant and so it would seem to be leaking through rather than seeping up, if that makes sense?

further pics to come shortly ...

Det Somerset

Ok so these are pictures I took a couple of months ago. It should be noted that the leaking is significantly improved since we attempted our DIY job. We had really heavy rain over the weekend and this level of water was no longer apparent, although a few persistent drips remain. The left hand side now looks more like that centre bit where it's still dripping with visible damp patches on the concrete but nowhere near the sheer flood that was getting through before.



The water leakage was so significant it caused a section of the unfinished ceiling to sag and peel off so we just removed that section entirely



The leaking isn't as bad here but you can see traces of damp drips so this area is also affected.



This is a view up into the section of the ceiling that we removed. I'm not sure how useful this is but this is about as much of the 'underside' as I will be able to show you. I don't believe I can see any fibreglass here.



This is a shot taken from the attic space above the room during heavy rain. I was trying to see if there was a leak in the roof that was flowing down to the valley (this was when I had believed them when the said there was no leak in the valley). This is pretty much on top of the area that I've shown above. Note that there is a section there which almost seems like it's beads of moisture between sections of wood, however unless I'm mistaken, it wasn't wet to the touch so it was like it was some transparent glue rather than signs of leakage.



Another shot taken in the attic

No idea if any of these pictures help.

Bonzo Delaney

Det Somerset wrote: »

Sorry for the delay in coming back. It's a little awkward getting up to the roof. I don't know if these help any further analysis but this is about the only other angle I can get.







The question I would ask is, what would the ballpark figure be to hire a professional to perform a long term solution here? I don't have a lot of cash currently so anything over 1000 I couldn't possibly afford and we'd have to put it off till next year, however closer to the 500 mark is something we could afford to get done soon.

Thanks again for the feedback and advice here

It looks about 7-8 meters long it'd have to be striped back and about 3 row if tiles also plus the 3 hip caps on both sides
Replace the ply underneath with osb 3 board then re fibreglass and top coat the valley.
The lead on the wall could be cut to leave a 75 mm apron hanging to flash over the new fiber glass upstand and the tiles put back neatly.
Probably would have to form a fibreglass gutter at the side wall where the roof extends at the front and flashed to the adjacent roof tiles.
All in a good days work for two good lads or lassies. Including materials and labour you'd do well to get out for 600€. You could be lucky and get someone who does it full time and might have some material left over from a job, and does you a turn. That's only a very rough estimate on just looking at pictures hopefully you get sorted. It'd be no harm to stick 2-3 vent tiles in that valley area of the roof to keep that dead end roof space ventilated.

Det Somerset

That's fantastic, Bonzo, thank you! The specifics of those instructions mean little to me but they will make getting an accurate quote so much easier. The original plans have the room underneath as being 6.7m in length so adding in the thickness of the walls it would seem you are spot on with your estimate of 7 to 8m.

I'm not sure I can ask any more of you here, so while I will keep an eye on this thread, this may be my last post on the matter. If that is the case, I just want to thank you again for your time, advice and expert guidance on this. Also thanks to wait4me for your advice even though it's not your main area.