Hi all,
We just had the flat roof replaced on our garage, which is attached on one side to our house (although it sits on its own wall)
The old roof had a felt / bitumen flat roof and it was leaking from the point where it met the rendered house wall. It had rotted some of roof joists. The previous owners had abutted the roof felt to the house wall render and siliconed it down, and that had been where it appeared to have failed.
The old roof has been removed, new boards put up and the damaged rotten joists replaced.
The job ended up being done in 2 parts
1) new lead flashing was installed above the roof, the boards were replaced and a new EPDM membrane put down. The membrane goes ~100mm up inside the new flashing which is ~125mm above the roof line on the house. At that point the wind picked up and the roofer wasn't able to glue the membrane down, but left it secured, with a plan to come back in a fortnight as it should have been sealed. We then had heavy rain and it leaked... a lot. I called him up and he came back within a couple of days to repair
2) the lead flashing was reset, the membrane glued down and the roof joists completely secure. This was yesterday.
Last night it rained, standard westerly wind and rain for ~ 2hours which blows over the top of the flat roof into the side of the house
This morning i have damp roof boards on the side which meets the house, so there appears to be ongoing water ingress from near the join
The render on the side wall isn't obviously damaged, so it shouldn't be bypassing the flashing and coming in from the inside. The amount of water coming in is worse than what we had before the roof replacement.
With a strong enough wind could water blow up and under the flashing and track into the roof underneath the membrane. Should this be sealed (as in the lead flashing sealed to the membrane? Do i need to have the whole lot replaced, and at whose cost? The guy who did it has done lot's to our house and this is the first problem we have had.
Slowly losing my mind.....
Photos would help, but first port or call is to get the builder in who did it to look at the issue.
I'm not a roofer but would have thought the 100mm of ovelap should be enough to stop any ingress. Can you get a hose and blast it to see what happens. Then at least you can show the guy who did the work the problem and also test it once he's fixed it.
Thanks jeffl
The hose is a great idea, because it will exclude the wall as a cause. Hadnt thought of that
I did have another look and wondered if I was just seeing the water pool at the bottom of the panels as it dries out.
Fortunately the rain gods are out today so I will probably know later whether there is ongoing leak
The flashing should be separate from the roof membrane to allow for differential movement, so no, it shouldn't be "sealed". As long as the flashing overlaps the membrane by 100mm or so it should be watertight (apart from a very small risk of capillary ingress). Given that you have a completely new roof I don't see that the roofer can possibly deny that it's down to them to fix it.
Photos?
As above hose pipe it.
Mine leaked intermittently with wind direction as the upstand wasn't cut into the wall enough. I put deep fibreglass flashings on over the upstand and pointed them up and it was fine.
https://images.app.goo.gl/FUTR514HD8Dhet8f8
Chase them in and clip them then point them up.
it’s still damp so going to wait and see before doing the hose test
tempted to put a baton in front of the flashing to see if it’s wind driven, but I need to see if it continues. The bolts which hold the joists in have little beads of water so I suspect ongoing moisture
Is that joint in the membrane on the right side of your second photo a bit dodgy?
That looks v similar construction to my garage attached to house the same way. Mine leaks too despite various attempts to repair over the years. I reckon the issue is wind and rain, it blows in straight off the sea and forces water into any gap, damp finds a route in.
My solution is a pitched roof, spendy and needs planning though. I plan to justify the expense by creating a usable space above.
The damp drove me mad too, once it's found a route in it just gets worse.
Thanks all
Rain overnight, the garage is essentially flooded.
Appears to be a major issue going on, its dripping actively from multiple points
Builder is on his way back to have a look
What is the overlap of the joint in pic 1?
I have had leadwork / flashing done before and the finish was 'very smooth', but yours looks very 'lumpy'.
What is underneath the flashing to cause that?
All that should be there is a 'smooth' upstand of the covering sheet lapped up the wall 100mm or so, sealed against the wall.
As previously pointed out, the joint on the right of pic 2 looks suspect.
If the garage is flooded there must be something else going on as well.
Thanks. Will get him to look at the join
Very paranoid now there is water running down from somewhere else. The rendered wall above is solid to touch, I assume if there was water behind it somehow it would start to lift off ?
We're about to have ours redone and they have given us two options, whats peoples thoughts on GRP vs EPDM?
*disclaimer - not a roofer* but that joint/ doesn't look great at all. My rubber roof looks visually much thicker, like one seamless rubber sheet.
Is the flashing installed into the grout, or is it just self adhesive stuff? If it's in the grout like most is, it shouldn't leak from above should it? Self advise stuff however depends how good the adhesive is.
But regardless, it's his shoddy workmanship. Leaving a leaking roof should be a priority for him to come and fix ASAP.
Is he a roofer or a jack of all trades who is out of his depth?
Looks from your photo like a narrow slot cut to take the lead and little space for lead sealant. Wider slot and whack more sealant in above the lead, maybe??
I reckon the leads not cut in deep enough and its not sealed well enough.
Lead should be cut in an inch.
The garage wall below rendered or does the render stop above the garage.
The lead flashing should be cut into the brick behind the render.
If the render fails and lifts away from the brick behind, its taking the flashing with it !!
Run some water seal along the bit where the flashing goes in.
Worked for us when driving sideways rain got through.
Thanks all. Quick update for completeness.
Builder has come back and added additional sealing strip above the lead. Did it this pm, it's not stopped raining so not sure if the water inside is new or old
He noted some render cracks on the wall above which he says may be the cause of the water ingress. This seems strange as more water comes in now than before the roof was done and this shouldn't be roof dependent
Guess I need to have the wall repaired now, garage still out of action:( unsure if the roof is weather tight or not
All our stuff is in the lean to which is not ideal
What is that he has added?
To my eyes looks like a plastic strip, fixed by screws and a tube full of silicone.
I'm not convinced that is a long term permanent solution.
Happy to be proved wrong of course.
Hmm.... That his temporary repair or his permanent fix? A bit rough if its the latter.
