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DIY Forum >> DIY - Building Questions >> Roof leaking
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Message started by Natedog on Jan 20th, 2021, 3:24pm

Title: Roof leaking
Post by Natedog on Jan 20th, 2021, 3:24pm

Oh joy!  Something else on the house is falling apart!
I'm still pottering about in the loft and heard dripping coming from by the water tanks.  On investigation, the chimney breast is wet and there is water dripping from the felt and ridge board.

This shows the wet area on the chimney
[gallery]Natedog/1611155662.jpg[/gallery]

And the water running along the timber
[gallery]Natedog/1611155683.jpg[/gallery]

This is the roof from the outside.  You can see there is no lead flashing on the chimney, but the render has (im not entirely sure what you'd call it) a thicker bit round the bottom which sort of covers the edge of the tiles.
[gallery]Natedog/1611155617.jpg[/gallery]

I'm hoping that the cause is just a crack in the render (there is one, but its raining too hard to get a photo from outside) and that the wind is blowing the rain into the crack.  Does that sound plausible?

My only concern is that the guy who did the new roof back in the 90s has done something wrong.  Is this felt meant to go all the way to the brickwork?
[gallery]Natedog/1611155707.jpg[/gallery]

I'll get a photo of the outside as soon as the rain eases up.  Would appreciate your opinion as to the best way forward.  I've not really had much experience with roofs in the past

Cheers

Title: Re: Roof leaking
Post by Natedog on Jan 20th, 2021, 4:47pm

here's the base of the chimney from the front.  you can see what looks like a patch repair at the bottom corner that's broken loose.  Also looks like there is a fair gap under the render up near the ridge

[gallery]Natedog/1611161046.jpg[/gallery]

and here it is from the back.  harder to get a helpful picture due to the extension roof.  I'm aware that the top of the chimney needs a bit of love!

[gallery]Natedog/1611161064.jpg[/gallery]

Title: Re: Roof leaking
Post by CWatters on Jan 20th, 2021, 4:58pm

Some old roofs, including thatched roofs, just used a mortar "fillet" around the chimney. This can crack causing leaks.

However you might find there is lead under the render - they may have rendered down over the step flashing so you wouldn't see any lead from the ground.

Title: Re: Roof leaking
Post by CWatters on Jan 20th, 2021, 5:02pm

Looks like we cross posted.

In the second set of photos you can see what looks like evidence of lead under the tiles .


Title: Re: Roof leaking
Post by Natedog on Jan 20th, 2021, 5:05pm

what do you think the best line of attack would be?  replace the cracked off lump in the corner and then stick some sealant into the gar between the render and the tiles?  or would i be better hacking the render off and replacing it all?

Title: Re: Roof leaking
Post by CWatters on Jan 20th, 2021, 5:18pm

I think there are options..

1) Get someone up there with a tube of something and fill any cracks they can find.

2) I suspect if you just try removing the render and mortar around the base of the chimney you will uncover more issues and end up doing.. 3)

3) Remove all the render and mortar, flash or replace lead flashing, repoint chimney, replace pots(?), re-render down to flashing. Spare roof and ridge tiles and scaffolding needed.

4) Remove chimney..

Sorry.

Title: Re: Roof leaking
Post by CWatters on Jan 20th, 2021, 5:24pm

The first picture suggests the leak is high up near the ridge. I think it needs a closer look to figure out how it might be getting in. Could be that gap but impossible to tell from photos.

Perhaps pay someone to take a look and try sealer while they are up there but ask for a quote for a proper job.

Title: Re: Roof leaking
Post by Natedog on Jan 20th, 2021, 7:09pm

And there was me hoping you were going to send me a link to a can of magic spray on magic stop leak stuff  ;D

Removing the chimney is a no no.  3 of the 8 pots are still in use.

Is this the sort of thing that might be covered on buildings insurance?  I'm guessing probably not

Thanks for the advice.  You have confirmed what I was suspecting

Title: Re: Roof leaking
Post by thescruff on Jan 20th, 2021, 9:37pm

You have step flashing by the looks of it but cannot see the cover flashing because of the render.

The ridge is always the weak point and you should have a saddle over the top of the tiles (under the ridge tile) it looks a bit dodgy in the area and repointing may help, have a good look up close and then another pic or 2.

There is some magic stuff on the market but it's bloody expensive, I'll let you know what it's called when my mate tells me.

Title: Re: Roof leaking
Post by woodsmith on Jan 21st, 2021, 9:17am

The lead underflashing looks like it’s been added to the bottom few rows of tiles, perhaps when the roof was repaired in the past. There’s a tile missing too which won’t help. If you can afford it I’d get the whole chimney sorted in one go, sealants may form a temporary fix but if the structure isn’t sound they can’t do a good job. Water is so penetrating, it amazes me that sometimes a crack you can barely see lets enough water into the house to cause major damage and up in the loft it’s out of sight!

Title: Re: Roof leaking
Post by Natedog on Jan 21st, 2021, 2:57pm

Local roofer recommended by 3 people we know is coming to have a look tomorrow and see what he can find

Title: Re: Roof leaking
Post by thescruff on Jan 22nd, 2021, 10:56am

I agree with Woodsmith, stripping it right back and re-doing it is always the best plan.

The sealant I would use is Westwood R230, amazing stuff, expensive, and may need a second coat.

Title: Re: Roof leaking
Post by Natedog on Jan 22nd, 2021, 11:02am

Been talking to my next door neighbour.  He did a fair bit of the building work when the extension was built.  Apparently the ex-husband didn't want to pay for new lead, so there's a bit at the bottom and that's it.  The few bits that you can see in the picture is all thats there  :-/

Title: Re: Roof leaking
Post by Natedog on Jan 22nd, 2021, 6:04pm

Roofer has been round this afternoon and had a look.  He has advised fitting a proper lead flashing around the chimney, which makes sense.   Hes also going to replace all the crumbling mortar around the small front gable end, and a little bit at the back.  

He wants scaffolding to work off, which doesn't seem unreasonable, and I can get the front of the house painted at the same time to get a bit extra value from it.

The only down side is he can't fit us in until the last week of Feb

Title: Re: Roof leaking
Post by woodsmith on Jan 23rd, 2021, 7:55am

Well let’s hope it’s warmed up a bit by then because it’s a bit too cold at the moment especially for sealants and paint.

Title: Re: Roof leaking
Post by Natedog on Feb 22nd, 2021, 7:21am

[gallery]Natedog/1613978461.jpg[/gallery]

Scaff has gone up over the weekend.  Hopefully should be watertight again by tomorrow  ;D

Title: Re: Roof leaking
Post by woodsmith on Feb 22nd, 2021, 8:12am

Glad you have managed to find someone to fix it, it’s hard to find anyone these days to do anything.

Title: Re: Roof leaking
Post by Natedog on Feb 22nd, 2021, 11:51am


woodsmith wrote on Feb 22nd, 2021, 8:12am:
it’s hard to find anyone these days to do anything.


Yes, I'd noticed that!  

Title: Re: Roof leaking
Post by Natedog on Feb 26th, 2021, 3:09pm

[gallery]Natedog/1614352078.jpg[/gallery]

All done  ;D

Looks a nice tidy job to me.  Just need a good storm to wash the dust off the roof now

Title: Re: Roof leaking
Post by woodsmith on Feb 27th, 2021, 7:35am

Glad you got it sorted, these sorts of problems can cause a lot of trouble down the line if you don’t get them fixed.

Title: Re: Roof leaking
Post by thescruff on Feb 27th, 2021, 1:20pm

Looks like a good job But, Not happy with the ridge.

I can't see what they have done underneath, the lead saddle should be under the ridge tile.

I would have thought they would have repointed the ridge while they were up there.

At the moment it looks like a hole where driving rains can enter.

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