Multiple Damp Patches on Roof

[terrypin]

If the ridge is letting in water then every bit of felt(under the tile)will be wet below the point of ingress.
I cannot understand every board being wet as the felt protects/prevents the water getting to the board unless there's a hole in the felt.

If every board is wet then I'd be looking at condensation as a possibility.

 

[chuckalicious]

His suggestion is that the felt may have rotted due to the amount of water getting in over how many years.

I hate situations like this. There is no evidence of condensation inside the loft in terms of wet wood or anything else, but it is definitely wet between the roof boards and the felt. I don't want to spend what would likely be the best part of £5k for a reroof only to find it wasn't needed, nor would I want to spend about £900 to find we need a new roof.

 

[chuckalicious]

Been back up and stuck my hand under a number of the boards and only the ones showing Damp are wet underneath. The others have totally dry felt.

Not sure if that changes things.

 

[terrypin]

If you spend £5k you'll never know.

I can't say for sure having not seen the roof but I cannot see it needing a completely new roof, otoh it is possible.

So, do you spend £900 and possibly save yourself £4100 or pay £5k and never know if you've wasted £4100?

Heads or tails?

 

[chuckalicious]

I am almost tempted to go the ridge route. Will assess when the quote comes in. Thanks for all the advice and opinions.

 

[ree]

Coating the Aquaseal with SBR might take and bond the mortar?

Why not follow the rafter bay or bays that show moisture up to the ridge, & have a roofer go up to that point on the ridge, and merely re-bed the nearby ridge tiles.

Get quotes for such a local, perhaps temporary repair - and see how you get on?

FWIW: it strikes me that your ridge board, & either side of the ridge board is bare of felt? ie. a strip of felt flopped over the board before the last laths were fixed - i used to, where it was possible, to insist on this practice. Even using a length of bitumen backed felt to give a bit of strength.

 

[chuckalicious]

When I get the next quote in I'll let you know what it says. Ridge is apparently 14m long.

 

[chuckalicious]

Got the quote in from the second guy.

£11k+vat for reroof.

£1400+vat for new ridge and verges. Wouldn't guarantee work as not confident the ridge is the problem.

Reroof is out of the question.

 

[chuckalicious]

Can anyone comment on whether or not the power washing of tiles and then painting with Aquaseal would cause them to become porous over time? This is the only suggested reason for a reroof and I need to know if it is in fact unlikely. The tiles are 30 years old Max so I would have hoped they would last a bit longer than that.

 

[terrypin]

The tiles in the photo look OK to me but, that doesn't mean they are.

Those tiles should be good for a few more years if untouched.

The problem is obviously an old one as why else would they have been coated, this has obviously not worked which suggests the tiles were never the problem so IMHO it has to be the ridge.

 

[chuckalicious]

I wish I knew why they were coated. They will only have been about 15-20 years old.

With the wetting Ive seen in the last few days, I would have expected more historic staining but there didn't seem to be much or any before last week other than the bits at either end of the roof.

The only thing done since we moved in was to get the ridge mortar where it meets the roof tiles patched as parts had fallen out. Can't imagine that could have caused the issue...

 

[catlad]

It could be that the roof was never counter battened so that maybe part of the problem. The new ridge system can be re-used if you need to re-tile your roof. Forget the guy with his 11 grand+ quote he is very greedy.

 

[chuckalicious]

It could be that the roof was never counter battened so that maybe part of the problem. The new ridge system can be re-used if you need to re-tile your roof. Forget the guy with his 11 grand+ quote he is very greedy.

Can I ask what counter battened would mean and how it would cause this problem? I'm trying to understand the issue and why it hasn't destroyed the roof in the 30 years it has presumably been there.

 

[terrypin]

Counter battens are fitted along the spars and the battens are then fixed to these, the result is a 3/4" gap between tile and felt.
It helps drainage and creates a thermal barrier etc.

 

[chuckalicious]

Thanks. I have gone ahead and accepted the first quote. I can't do nothing and I can't in any way afford a reroof after spending everything on moving so I see this as the only thing to try other than buying lottery tickets.