Roof + chimney issues - advice appreciated!

[andrewd8323]

Hi all

 

Hope you're well. 

 

In the summer I had my house re-roofed (new membrane, new battens , new thin edge sandtoft concrete tiles, and new dry ridge system and the roofer rebuilt the top few courses of the chimneys as they didn't have drip courses and repointed the chimneys).

Immediately after completion, I noticed that the wooden rafters were getting damp in some areas (always the same recurring spots).

When the rain stops and we have a dry day or two, the woodwork then dries out.

I've been in the loft during heavy rain and weirdly, I can't see any water drops coming in or any water flowing down the rafters. However, once it is has been raining a few hours the timbers have visible damp spots, are damp to touch and are showing elevated readings on my damp meter. I'm therefore wondering if the water is slowly penetrating the wood via nail holes or something (e.g. where the battens are attached to the rafters)?

I've set out a couple of videos below:
 

• The first video here shows the wood dry, with low readings from the damp meter
• The second video here shows the wood damp. As soon as the video starts you can see clearly that it is damper, and the damp meter then confirms this.

 

Excuse the commentary on the videos - it is directed at the roofer. 

 

The roofer who did the work has been round and said that because we can't see water drops coming in, the roof must be fine. He is totally ignoring the damp marks / elevated damp readings etc. However, I'm concerned that if I leave the wood to keep getting damp each time it rains it will eventually rot / get mouldy.

It's all getting quite tense as I had only paid 75% of the roofer's bill when I noticed the damp spots. I held back the remaining 25% as I didn't want to pay this until I am comfortable the roof is watertight.

 

Since then, we've had plenty of rain and we've now also had damp marks develop on the chimney breast in our bedroom - I've attached a photo of this below.

I've also been in the loft during heavy rain and the chimney breast has been wet to touch - video here

I got an alternative roofer round to look at the job. He said that the flashing has been done incorrectly on the chimneys for the roof tile that's been used.

I then took a photo of the flashing and sent it to the tile manufacturer, who agreed it hadn't been done right and said soakers needed adding due to the flatness of the roof tiles that have been used - I've attached a photo of the flashing below.

The roofer who did the original work came round yesterday, peeled back the flashing and essentially said "there is no evidence of water getting beneath the flashing, the roof is all fine. Moist air must be entering the loft from the house then condensing on the chimney and running down into the bedroom beneath. You need to insulate the floor of the loft better and less moist air will get up there".

I'm feeling at a bit of a loss now. I'm struggling to believe that the issue is condensation given:

• we've been told by two other parties that the flashing has been done incorrectly.
• The size of the staining and amount of water seems high for condensation.
• We also have a dry hip / ridge system, breathable membrane and vented eaves trays, so I would have thought there is enough ventilation up there to prevent significant amounts of condensation.
•  I've only seen the chimney in the loft get wet during periods of heavy rain. I went up there yesterday morning (which was a very cold morning with no rain) and the chimney was dry to touch. If this was a condensation problem I would have expected it to be wet on a day like that as the bricks were very cold. So I'm really struggling to believe it is condensation issue..

So this is just a broad plea for any advice really - any suggested next steps?! What would you do? I still haven't paid the balance of 25%. The chimneys have become my primary concern given the damage it is causing inside of the house, but the wood issue is still there in the background.

I can think of various possible next steps regarding the chimney:
1) Ask the roofer to fit some vented roof tiles to further increase airflow in the loft - if the problem still happens after this then it surely confirms it can't be condensation. This wasn't in the original scope of work so would probably cost me c.£400
2) Insist the original roofer does the flashing as per the manufacturer's instructions - I think this should be free of charge given it currently hasn't been done correctly. 

3) The issue has only emerged since we had the new roof put on / chimneys worked on, so I'm confident that the issues relate to something they've done. However, I'm conscious that there are other things which may not be helping eg I don't think the roofers painted the chimneys with stormdry when doing their original work and I don't think the chimneys have chimney trays. I could therefore look to have them painted with stormydry at a minimum, or  more extreme, I could have the chimneys rebuilt so that they include chimney trays. Rebuilding would clearly be quite expensive but I could potentially save a bit of money if it was done at the same time as action 2 above (as scaffolding would already be up).  

 

Regarding the damp patches on the wood I've less clarity about potential next steps. 

Thanks all

Andrew

 

 

 

 

 

 

[Redbeard]

So there are no soakers below the flashing on that chimney? I am not a roofer but surely you always have soakers on abutments? I do.

 

I don't fully 'buy' the condensation reduction argument. Increasing insulation will not reduce condensation - it could increase it (because you are making the void even colder) unless something is done at the same time to effectively incorporate a VCL in the entire 1st floor ceiling(s).

[andrewd8323]

1 minute ago, Redbeard said:

So there are no soakers below the flashing on that chimney? I am not a roofer but surely you always have soakers on abutments? I do.

 

I don't fully 'buy' the condensation reduction argument. Increasing insulation will not reduce condensation - it could increase it (because you are making the void even colder) unless something is done at the same time to effectively incorporate a VCL in the entire 1st floor ceiling(s).

Hi thanks for responding. Correct -there are no soakers. I don't buy it either! 

[AliG]

Original post edited with additional info

[andrewd8323]

37 minutes ago, AliG said:

Original post edited with additional info

Thanks!

 

[andrewd8323]

Hi all

 

The damp marks on the chimney are getting worse by the day unfortunately. I'm guessing the back gutter could be a potential source of the problem given where the damp marks are? I've therefore taken two pictures of it which can be found here and here 

 

I've also taken a video of the back gutter that capture more aspect of it here. Apologies it's a bit wobbly - I was up a ladder with my phone sellotaped to the end of a pole!

 

While I was up there I noticed that the pointing on the stack was darker in places and there were streaks on the chimney (as part of the re-roof the roofer re laid the top few courses of the chimney and repointed the entire thing). I'm not sure if this could be related to the issues? I've therefore also taken a video showing the full chimney stack here. 

 

Thanks in advance for your help

[AliG]

You don’t need to prove anything. The manufacturer says it has been done incorrectly. That should be the end of the argument.

 

I would write to the roofer and say either he fixes it to manufacturer’s specification or you pay someone else to do it with the retention and you will either return anything left over or pursue him for any extra costs.
 

I am not a roofer but clearly if water gets under that flashing it will go straight into the roof.

 

[andrewd8323]

1 hour ago, AliG said:

You don’t need to prove anything. The manufacturer says it has been done incorrectly. That should be the end of the argument.

 

I would write to the roofer and say either he fixes it to manufacturer’s specification or you pay someone else to do it with the retention and you will either return anything left over or pursue him for any extra costs.
 

I am not a roofer but clearly if water gets under that flashing it will go straight into the roof.

 

Thanks AliG and appreciate the reassurance -  I agree I have strong evidence and I’m in an ok position from that perspective.
 

 I think the main thing I’m hoping to understand from posting is if people can see anything else that is wrong or if people have any tips / suggestions.  Because of what’s happened I’ve lost faith in the roofer who did the work so I’m worried that there are actually a number of problems and I want to identify them all before commissioning corrective work… I would hate to fix one problem only for another 3 to still be present 

 

 

[AliG]

I have a lot of sympathy with that. Would I want someone else to do the job, especially with their ridiculous explanations.

 

The funny things is the work that has been done looks very neat and tidy.

[andrewd8323]

Thanks all for input so far.

 

One additional question: the roofer repointed the chimneys at the time of doing the roof. I’ve attached a picture of them below. What are people’s views on the pointing? Look ok? I ask because the different shades look a bit unusual to my untrained eye. Could this be a source of the problem? I don’t think the chimney was painted with storm dry when it was worked on. If I did this would it  protect both the bricks and pointing?

[markc]

I haven’t looked back to see what problems you are having but the pointing looks to have been done where required rather than raking it out and repointing everywhere, bit untidy but looks sound

[Balfron Tower]

Your roofing issues look to be the same as we faced after a new roof was installed. Did you manage to get it resolved? We found a new roofer to fix our roofing issues as did not trust the original roofer who installed the new roof. The new roofer installed new heavier lead flashing / back gutter along our chimney, and welded this (it previously was not welded and water droplets were rolling down the chimney wall). We also had some wet patches on the top side of the roof hip, which I believe is from water ingress somewhere along the hip, the original roofer did not cut the slate tightly against the hip and so the ridge tile overlap was very small. We are planning to replace the entire problem hip with a lead rolled hip, and hoping that resolve the issue.