Roof leak due to faulty work

[phil147]

Hi,

I have roof leak recently and received useful help from quite a few members in this forum. Thanks again. (//www.diynot.com/forums/roofing-guttering/roof-leak.383334/)

After telling the roofer his installation of soakers hasn't stopped the leak, he came back and removed more roof tiles to investigate.

Basically, he said the Main roof pitch is about 16 degree and the Redland Stonewolt tiles used have a minimum pitch requirement of 17.5 degree. In addition, the head-lap is 2.5 inches instead of 4 inches for the 17.5 degree roof pitch. He said the leak might have been there for a long time and the felt only failed recently (It's a 14 year old terraced house)

He said he will phone Redland and see what could be done and think about something.

Could you please advise what are the possible remedies? Would paint the roof with acrylic roof coating help? Since it is a terraced house, it is unlikely I could just change the roof pitch of my house. I might ask my neighbours if they have any problems with their as well.

Also, it looks like the original developer did not install the roof properly and NHBC inspector obviously didn't pick this up. But the NHBC warranty has expired 4 years ago. Is there anything I could do?

Thanks again for your help.


Phil

 

[Alastairreid]

Remove the bottom 4 or 5 courses of tiles and renew the perished felt.

If you use felt support trays and a decent grade felt it should last another decade.

Painting the roof with compound wont work.

 

[phil147]

Hi Alastair,

Thanks for your suggestions.

I've managed to get in the attic and took a pic of the corner where water leaks onto the ceiling.

It definitely looks like the felt has failed and needs to be replaced. Do you know whether felt support trays can be fitted to this type of roof end?



Cheers,

Phil

 

[tony1851]

That flashing against the parapet wall has not been done correctly, no wonder it leaks.

 

[phil147]

@tony : hi, could you please elaborate what's wrong with the flashing? I am no expert so would really like some advices so that I know what to look for and talk to the roofer. Thanks!


@alastair : The Redland technical advisor suggested me to strip off the roof and re-laying the tiles with 4 inches headlap! I just can't afford that. I am keen to investigate your solution of renewing the perished felt. As a guide, how much would it cost to do (The roof is about 4 metres wide)? I've already spent a grand on it without fixing the leak and my budget is getting tight now

 

[tony1851]

There should be separate lead soakers to each slate, and then the cover flashing over the upturns - see page 15 of this;

http://slateroofers.org/downloads/lead_flashing_guide.pdf

 

[Regencyroofingipswich]

In my opinion it looks like it needs a GRP wall abutment flashing installed.

 

[phil147]

Hi tony, regencyroofing, alastair,

Thanks for your comments.

The roofer has already installed lead soakers which he claims should stop water at the tiles/parapet wall interface. However, the leak is still there, and from the attached photo, it seems water still running onto the ceiling and the wall through the degraded roof felt.

As the leak only occurs when it rains heavily, I assume this is likely that due to the low-pitched roof (18 degree), wind-driven rain water get on the felt and for whatever reason, runs to that corner of the roof.

I would expect if water was coming through cracked coping stones, bad pointing... etc, water would only come through the wall below the ceiling, but not on the ceiling itself.

That's why I think alastair's suggestion of replacing the perished felt is the cost-effective way to deal with it now bar relaying the tiles.

Am I correct in my assumptions? There is so much to learn and I found it quite interesting. I can't help but keeping looking at roofs nowadays while walking on the street

 

[catlad]

You now probably know more than your roofer, do it yourself or get another roofer.

 

[Alastairreid]

You now probably know more than your roofer, do it yourself or get another roofer.