Chimney stack bricks soaked causing small water ingress into bedroom ceiling

[frustin]

Moved into a 300 year old Georgian grade II, 1.5 years ago. First thing we did was get a roofer to fix the roof issues, including replacement of all flashing around the stacks. No issues since then, however, we've had a lot of wind and rain recently and there's some water staining appearing in the bedroom ceiling. The area of ingress would be on the stack side, favouring the prevailing wind direction. You can see that in the pics as that part of the stack is darker and has bits of moss growing.

We called the roofer again and he's checked it. He took pics (that i've asked for him to send to me to post here) and showed the site of the the work he did and the bricks. They are sodden and suspects that it might be the cause. He has suggested a potential spray barrier (which he'll get the name of) but i've said first need to make sure it's suitable for the type of bricks and mortar used in the construction of this type of building.

He did say that he could just spray that one side of the bricks (facing the wind) and maybe that will be ok, but again i thought i'd ask you guys first if you have any suggestions for this type of fix?

 

[Kearn]

No images uploaded, but water ingress is rarely a simple one when looking for the entry point, as moisture happily tracks a long way before finding an exit point.

Saturated bricks do happen, less chance of leaks if the pointing is in good shape.

Chances are you need to do some more investigation to fully understand the source of ingress.

But, certainly, do not spray anything modern on the bricks to seal them. It is not the answer and will cause more issues. Seems like your roofer is clutching a bit to pop a sticking plaster on rather than finding the cause and dealing with it.

 

[frustin]

Thanks for the response!

What investigation can one do? He went up there, the work his company carried out looks sound. Be interested to know what else there is when it's not obvious?

I've asked him for the photos and i'll post them later on.

 

[stuart45]

Driving rain will get through the brickwork on a stack and run down. It's why you have to put lead trays in stacks nowadays. It wasn't as much of a problem years ago, because fires were usually lit first thing in the morning, and burnt all day, so it kept them reasonably dry.

 

[frustin]

I would say, looking at old photos, that the chimney hasnt been in used since before 1900 and is capped. but i guess that doesnt preclude it going all the way through the bricks

 

[stuart45]

Is the flue ventilated?

 

[frustin]

I have no idea, the breast was clearly covered over a long time ago. neither the bedroom nor the dining room have breasts.

I'm going to go with no.

Here's a pic of the water damage in the bedroom. You can see it's not much and this is new since we moved in.

 

[stuart45]

Is the chimney flue an external one, where the brickwork outside comes out from the wall?

 

[frustin]

yes it's external, here's a picture. NOTE: this is an old pic from when i moved in. so new lead work has been added around stacks.

 

[stuart45]

Lead flashings won't stop the water that gets through the brickwork and running down the flue.
Google just lead chimney lead tray video.

 

[Kearn]

His leadwork may not be adequate. Not all leadworkers are equal.

It may be driven through the bricks, you’ve likely only got 4” of soft old porous clay there to saturate.

Any gaps in pointing will let it pour through. Your pic shows areas of darker cement pointing lower on the stack, is everything above roof perfectly done.

Where in relation to the external features is the wet patch.

 

[frustin]

he's sent through two of the 4 pics, i've asked for the others which i think show the lead a bit better....

 

[stuart45]

On site the lead work was always the plumbers job, although in recent years there is a separate lead workers trade. However, in the private sector it's normally a roofer who does the work, especially if he's a sole trader.
In general, a roofer isn't as good as a plumber, or lead worker for flashings, back gutters, front aprons or trays. The problem in the private sector is getting someone in, apart from a roofer.

 

[Cubist]

A couple of dumb questions perhaps but, I'm well known for them;

• Have you been in the loft, since this damp spot appeared, to examine the corresponding section of the roof and track any apparent leakage back to the chimney stack or elsewhere?
  • You should be able to trace the path of the water back to its 'internal' origin either in/on the stacks masonry or the woodwork behind the guttering or a leak from between the tiles.
• Is it safe to assume your first photo was taken before the work on the roof and stacks was done?
  • The chimney flashing nearest the camera looks to be in poor condition.
  • Oops, just re-read the opening line of your first post - so please disregard my second question

 

[stuart45]

This might also seem a stupid observation, but the first photos look like slates, but on the later ones look like single lap profiled tiles.

 

[frustin]

Have you been in the loft, since this damp spot appeared, to examine the corresponding section of the roof and track any apparent leakage back to the chimney stack or elsewhere?

I did go up there with lots of lights but cant see anything. To be honest i was about 3meters from the area affected but i could see the brick of the chimney. My untrained eye didnt see anything, the damn patch started a couple of weeks back.

Here's the close ups from the roofer, you can see that he's done a back tray but in lead and it's welded.

 

[frustin]

ut, certainly, do not spray anything modern on the bricks to seal them. It is not the answer and will cause more issues.

this was the stuff https://www.screwfix.com/p/stormdry-masonry-protection-cream-clear-1ltr/388cn - But it's not going on my house!

Roofer thinks it's probably open (rather than sealed) could water be coming down this?

 

[Cubist]

Roofer thinks it's probably open (rather than sealed) could water be coming down this?

I have experiences from just last year of rainwater ingress through the stainless steel flue pipe to one of our wood-burners. It is entirely possible for an unsealed chimney to admit rainwater that ultimately finds its way to almost only location BUT the damp you are seeing has appeared outside the masonry structure of the chimney at a high position. This would indicate that any water entering through the chimney would have to have found a weakness in the masonry very near to, but below the height of the new external leadwork. That may be feasible but I would argue unlikely. To my mind it would be more likely that the necessary disturbance of the tiles needed to install the lead tray could be the culprit.

 

[Kearn]

I’ll be honest, that leadwork is looking like it’s probably going to be your source. It’s not wonderful and the fact he’s slapped a load of sand and cement into your bricks rings bells…coupled with his desire to seal your bricks.

The location of where I’m assuming the damp is (basically eaves?) would indicate that water is getting in at the chimney/roof interface, or not much further away.

If it was coming down the pot it would carry on down the flue, unless there’s a gaping hole in the brickwork in that location.

If he was up there working surely he should know if the pot open or capped? Looks open from the fuzzy photo, but the way to tell is being next to it to check…

 

[Kearn]

I did go up there with lots of lights but cant see anything. To be honest i was about 3meters from the area affected but i could see the brick of the chimney. My untrained eye didnt see anything, the damn patch started a couple of weeks back.

Here's the close ups from the roofer, you can see that he's done a back tray but in lead and it's welded.

View attachment 19347View attachment 19350View attachment 19348

I’d want to know how far the lead is lapped under the slate - it’s a shallow pitch and any water running down and hitting the stack could push back up and under the slate.

Where exactly is the damp spot in relation to all these external photos?