So refreshing to hear a builder advocating lime mortar these days! Thank you for the video, Roger

Sorry but to me that looks to be extremely poor leadwork. Too many people don't even know about Soakers or the need for substantial overlaps to keep wind driven rain pushing water up over Soakers if they are fitted, and around Corners, the only way imho to ensure that it is a good job, is to take it apart and start again from scratch. If ot is done properly, Roofers Tippex (Low Mod Neutral Cure Silicone) or Mastic are not needed. tbh, we need to start up proper Apprenticeships again, withbsome decent Roofing Courses at Colleges again. Our Apprentice was on the last Roofing and Slating College Course in Wales, believe it or not, and did an Exhibition Roof Competition at the NEC. He was the inly one who finished off the last course of Slates at the Ridge Properly and securely. The Construction industry is in a bloody bad state all around sadly, and not just in Britain and Europe, it's a Global Problem. Best Wishes. Bob. 😔

Hi Roger, Looks to me like the soakers are Not over lapping so instead of discharging the water downwards its going straight down into roof space. That indicates whoever did it doesn't understand the principle of flashings and there could be other mistakes with it out of immediate view. Met a few roofers who didn't understand about soakers.

I did up a house built in 1850’s and had this exact problem. Had a roofer up two times but was still leaking. After some thinking I came to the conclusion that the whole chimney was like a giant sponge. So spent £1500 to get the chimney replaced. Problem solved.

You mentioned a drone for getting photos. I used some plastic pipe I had laying around taped together with a camera strapped on the end. The flexiness meant it kind of hung over the ridge and pointed directly down at the gutter. A bit of trial and error but worked well.

The stone/brick looks very porous, so pointing with a sand/cement mortar is probably not a good idea. Looking at the stain on the ceiling, I would think the problem is probably to do with the rear gutter. A couple of images of the back gutter may have made things clearer. I had a job where the gutter was holding water as it was blocked with organic matter, and when the wind blew the water went over the lead flashing and into the building.

I had a similar issue on my chimney, different story, concrete block. The render had been frost damaged over the years a d water was getting in, wicking down and coming out in a huge wet patch in the wall, the concrete cap had gone porus as well I think, I re plastered it and built up what was missing from the cap, no problems since, I think part of the problem was the fireplace for that chimney had been blocked off for years and wasn't vented. I was redoing the floor in that room so I just broke into the old fireplace from under the floor, blocked it off in the room, and now we've good ventilation up through the chimney from under the floor, I think that has a good part in keeping it dry too.

I had exactly the same problem with our chimney, so much so I needed to catch dripping water inside the loft with buckets. I found a crack on the concrete plinth on the very top of the chimney so made a metal cover for that. Coated the whole chimney with Thomson’s water seal…..never leaked since. Interesting video, thank you for sharing.

Another great video Roger, you could (and should) make a full series on common chimney problems. I’ve lived in properties where chimneys have been taken out badly creating structural issues, others that have leaked and been damped like this one. And I’ve found that some roofers don’t want to get involved and some builders just pass it off to roofers.

There's an option I used on two chimneys at my terraced house: render then with a drip strip at the bottom and finish with masonry paint to match the colour of the house walls. I also replaced the haunching around the chimney pot with a harder mortar with a steeper slope to shed rainwater and fitted a metal rain cap with mesh below. I love my woodburner but others can use the chimney to vent a gas boiler (or mount a TV aerial). Chimneys have many uses!

It's definitely coursed stone, looks like West Yorkshire (where I am) or possibly East Lancs. That strap pointing was done all over in the 60s to 80s. The structural mortar is of course lime mortar.

Hi Roger. Agreed about the pointing. Regarding the waterproofing (stormdry or other), on chimneys, its must important that the haunching and pot are absolutely weatherproof to prevent excessive moisture soaking down the brickwork and overwhelming the breathing capabilities of the paint on barrier as this can exacerbate the internal damp problem.

A few years ago, I had a similar problem with a damp chimney in the attic of our c1912 home. The builder I got in to examine it could find no problem with the structure, render, flashings, etc. The only thing he could suggest was a chimney pot cap to stop rain dropping down the chimney but he couldn't find a cap that would securely fit the oddly shaped pot. I made a cap from 6mm stainless steel plate, which I secured with homemade hooked clamps down the chimney. I also incorporated a 25mm galvanised wire grille at the top, under the SS plate to stop birds nesting in the chimney. The result was a completely dry chimney (& one impressed builder). 😊

Roger - literally watching as I’ve a 1930s property bit of a leak down the inside of ours and thought “Stormdry” brilliant stuff would recommend to anyone but didn’t think it would be suffice on a Chimney! Your a legend fella 👍

The biggest issue in general is most chimneys don’t get used anymore. I had a job had looked couple times tried multiple things could not get it resolved then 1 time I went back up the the tiniest little pin prick on a welded corner sealed that sure enough resolved it water gets in anywhere

Roger, before even watching all your video, I was 99% certain it was driving rain getting through, I know because I’m a builder and have seen this a few times and even on my own bungalow. I live at a 1000ft in rural Wales, we moved 3 years ago and was getting water on our lounge ceiling, stack was soaking in the loft, I redone the lead, repointed, re flaunched it, still getting water, gave it two coats of Thompson’s water seal (not as good as storm dry I know) and it’s been fine since, I do it every summer now. Since then I’ve done it on other properties with the same results, you cannot underestimate how much driving rain will penetrate brickwork, they even call for minimum 120mm cavities here because of it.

Hi Roger, I clicked on this one because I had too many good years trying to solve this sort of problem I did fail a few times and did manage to get to the bottom of most of them, the first thing I notice is that all that new plaster inside was holding all the water used in the mix, about three times as much water as dust!, all that water was just sitting there and as always takes along time to evaporate and even then if it cannot escape will condense on any cold surface. The next thing I was looking for was where was the damp inside?, if it is on the underside of the ceiling and how much is on the wall, the damp that I have seen on walls has never come through the roof, I am not saying that this cannot happen, just that I have never seen it. There was one chimney where I opened up the roof and found no visible issues yet there was some damp on the ceiling. Here you have roughly equal amounts of damp on the ceiling and the top of the wall!. You do not say if the new ceiling was fitted with a vapour barrier and insulation but even if it was it would have been very difficult to seal it at the chimney. The result of all that isn that I would have to open up all the roof from the front all the way up the side and across the back gutter seeking any water tracks, even then absence of evidence is not evidence of absence so re-instatement would involve a new back gutter properly fitted soakers and step flashing and front apron. There would be no guarantee that this would solve the problem!, the two other issues remain unresolved. the second of which is that the chimney itself if unused and capped can trap wet air which will be absorbed by the old soot, that has property known as hydrophilia!, it will soak up moisture if any is available, this moisture will then cool the brickwork when it evaporates the heat then comes through from the inside, the temperature inside can then drop to below the dewpoint of the air in the attic!. There were many occasions in the past when the eyes of the builder that I was trying to explain all this to simply glazed over!, in fact even now I do not actually know for certain that this ever actually happens, just that it is consistent with the laws of physics and chemistry!. I write this and post it to you in the fond hope that you do have the wit to understand it!. Cheers, Richard.

I have only just remembered that I came across a similar problem to this many years ago in a loft room. It turned out to be condensation running down the felt (due to lack of roof void ventilation) and accumulating at the back of the chimney. Condensation could also take place near the top of the chimney breast itself as this will be relatively cold in the winter. Therefore, if the problem is absent in August its probably at least part condensation. If the chimney is used you would also get condensation on the inside as the warm rising air meets the cold building fabric close to the exterior. The other consideration is hygroscopic damps - the products of combustion produce many contaminants, some of which are hygroscopic and these salts may leach into the brickwork where they will absorb damp from the room - which may be humid. I noticed when last in France that they sometimes clad external chimneys with zinc to provide a rain screen as it is virtually impossible to otherwise prevent damp to a chimney breast which is only inches below a saturated stack.

I like the chimneys in Brittany, France, they tile them, seems to keep out the similar weather we have in the U.K.

Use some stormdry or other brand on the chimney stack walls. Make sure the top of the stack is waterproofed with some slate on a slope or some domed profile. Then fit a Rain Cowl with Mesh or Aspirotor spinning Cowl. The spinning cowl is better because it helps the natural updraft of the chimney drying from inside to out. Point to note. Check the chimney for an opening or air vent down stairs.

This house is made from Yorkshire sandstone delph walling, the house next door has been sandblasted. The pointing is way to strong for the stonework, eventually this strength of mortar will destroy the stonework with freeze/thaw, you can’t see all of the chimney, he needs to get up to the roof to have a proper look.

I had a similar issue with the chimney being wet in the loft. The roof was 90 years old, so we replaced it and also had the chimney re-pointed. The issue continued, I applied stormdry to it and also fitted some chimney caps/cowls/tops. This was done in the spring and 2 years later I've not had the problem again and the chimney inside the loft has stayed dry.

Great video Roger, I'm with you all the way on the ribbon pointing. Not only can it lead to water ingress, it leaves the masonry vulnerable to frost damage. Another issue to bear in mind with chimneys is that leaks can wash hygroscopic salts (from soot) into the plaster. The salts then absorb moisture from the air keeping the plaster permanently damp even if the original leak is fixed.

I got fooled by a damp chimney breast. I went up & repaired the chimney rendering, checked all the flashings, ventilation cap etc. And what it turned out to be was hydroscopic salts from 90 years of fires had saturated the fabric of the chimney. So in damp weather, it attracted moisture just as leaving a bowl of table salt out does. I largely resolved it simply by painting the chimney breast with Stainblock & ensuring good ventilation through the unused chimney to keep it as dry as possible.

Is there a lead tray within the chimney? Stepped lead flashings are designed to protect the junction of the brickwork to the adjoining tiles. They do not stop wet bricks allowing water to pass down into the roof void, this is the job of the tray.

The thing with chimneys is that they are meant to be used. They are designed to have a good fire blazing away, and the hot fumes would dry out the brickwork. If this is not the case, then the chimney should be capped preferably with a lead sheet on a timber former. I agree with sealing the brickwork also. Both methods used together, will prevent water ingress past the lead flashing, as you covered with the dpc comment. The front lead apron would benefit from a bigger upstand, in line with the stepped flashing to the sides. Also, to me it looks like the plaster has been applied to the chimney directly, whereas it would have been better if it were battened out and plasterboarded.

1min 30 seconds in ….,thermal image the chimney breast & take photos Then garden hose out of the loft window & saturate the c/Breast ….thermal again Depending on outside temperature & fabric temp ….you should see something V difficult (but we have done it) connect G/hose to hot water from combi & spray area with hot water You then have the cooler brick work + hot water / now you have a larger temp differential….easy to find weak spot or spots

Really useful video. I have been working my way through the same issue and had decided to use Stormdry next summer. Stupidly I have closed off the chimney to stop the draught in my lounge. So will also open up the chimney (hadn't thought of that before seeing this video).

Great advice, I’ve got a chimney with exact the same problem. I’ve checked the flashing and all possible issues for Water to get in. I’ve even added an extra event in the chimney to create more airflow. Mel has worked. The chimney is at the corner of the house so therefore there is no possibility for water to evaporate before going into the house inside the roof void. It looks like I’ll need to use storm dry to stop water getting into the brickwork in the first place. I have damp problem with two out of three chimneys all in sum on positions. The puzzler but I’m feeling that storm dry is the only option available, which I’ll do this summer. Thanks for the insight. Aidan

The rear of my house faces the weather - wind driven rain - and I gave it a coat of storm dry and I swear it even made the rear rooms warmer as well as waterproofing the wall, all for a couple of tubs of it!

Easiest thing would be to take down the damp plaster area and expose the chimney from the inside. Dry the timber and wait for the next rain fall, find the exact spot where the water is coming in.

Iv had a roof issue at one of my BTLs for 7 years. Countless roofers couldn’t fix it. In the end I removed the chimney. Think theres still water getting into walls a bit but not as bad. Some projects make no sence.

good video roger !! looks like its leaking at the back of chimney as the water marks on the ceiling is a telltail sign and can definately leak by the silicon holes by the flashings !

As you have already hinted at it would appear the damp is trapped within the internal finishes - easy to say but it is advisable to open up internally , inspect and allow to dry out.

The lead flashing on the side don't overlap each other for my liking . As said a water seal would help if nothing else is done , simple DIY job too

Very pleased to see you now recognise cement mortar traps in damp whereas lime will help damp escape.....

Could need a lead tray in the chimney and repointing in lime also vents in the chimney would help

At 2:18 to 2:40, I can see that the chimney is leaning to the left; while pretty much square to the roof it isn't vertical. I don't know if that's a cause of the dampness, an effect, or just a red herring, but it doesn't seem right.

New lead work is needed, new front apron side flashing and back tray are needed

In the future you need to give out the area of where these houses are because not only might there be someone there who could fix it, but also local knowledge (of weather and materials) is very useful. It would also be good to know where the most winds are coming from in relation to the leaks. It looks to me like a North Eastern Lancashire house, possibly Colne or Burnley, somewhere round there. WDR and porous stone is a big problem in that area and the fact the house next door has been painted says something. I would agree with Stormdry, but need to warn you of something. If it's done with that and then needs repointing, the pointing won't stick! That is if it's managed to soak into the joints, maybe all that horrible strap pointing will stop it. The other thing to note is that some of the houses out that way (Pennines) get so much WDR that it even gets through Siloxane, wets the wall and still runs in.

Sorry Roger - not bricks... Yorkshire stone. I had the same problem with my back gutter. Replaced it, but still got water seeping in when the wind drives the rain against it. My chimney is brick. Eventually I gave the whole chimney a coat of that silicone cream. That solved it.

I've also noticed the gaps in the fibre cement slates, depends on where he lives & which way his house is pointing he could have water being pushed up under those slates. basically like a capillary action. If he finds that most of the time the wind blows over this side of the roof then there's your problem.

Interesting, i dealt with a stack with saturated bricks, even in the middle of summer with flashing that was fine etc. stack had been used to burn coal only all its life, my conclusion was that soot attracted moisture and kept the bricks wet all that time. In the end the stack was removed and the lower brick was coved with a independent stud wall with plaster board.

chimney being damp normally would show on the plaster on chimney breast in bedroom below ... looks like its coming either through a cracked or missing slate above chimney or more likely poor / damaged flashings around chimney. Far too strong a mix used on the stone work ..would of been better to use a lime mortar. There's premixed lime mortars available with lots of colours available now that helps make it a fairly simple process. Just read what Richard Harvey wrote and agree 100%. well done Richard for a well written explanation 👏

Normally I would be critical of siloxane treatments as I am not convinced they are a good idea, however I have used them in a very localised manner and found they can work where all else fails. My advice is don't go to the siloxane as a first port of call as repointing in lime should work, but as you say it might need a bit more help? A point worth making is that traditionally chimneys were always in use and this kept them dry, but today they are rarely used and just get wetter.

Looks to me like Bradford / Halifax / Keighley area. I suspect the soakers and back gutter. As built these had a very narrow & sloping back gutter, so when you replace the slates you can't just bang in new lead, it needs new wood under to support it too. It looks to me like the rear gutter has just been 'bossed' that's to say formed by hammering it, rather than lead burning (welding) it. I suggest get a proper roofer to strip the slates then replace & / or inspect the soakers making sure they are fixed to the batons and are the correct height & width. The step flashing front corner requires replacement as does the pointing, as mentioned. Lastly the back gutter may need removal for full inspection as even pin holes can be enough to cause a problem. The back gutter upstand itself should be covered by a flashing pointed into the stone ( yes, it's stone) at least 4" above the flat part of the back gutter.

I live in a cottage built in 1820, water running down chimney in loft. The bricks were soaking water like a sponge. Stormdry solved the problem. Fantastic stuff. Goes on white and creamy but soaks in and then after a day or two you'd never know it was on.

I've done chimney flashing for slate and cedar for decades...Those flashings are a mess, holes everywhere...Here on the east coast; The lowest part of the chimney would have a 12 inch copper counter flashing that goes over a 6X3 flashing that goes on top of the last course...The first step flashing, gets wrapped around the front and the cut runs long on the roof and soldered, each step gets soldered on the chimney side then counter flashed, cut into the bricks, The counter flashing should have a less than 90 degree bend and gets pointed in. Each counter flashing is soldered to the one preceding... The high part is one piece that wraps unto the last step...Solder all joints...

It isn't just to strong a mix it isn't weather struck, the top of the pointing protrudes past the line of the masonry and it should "tuck" under it. Aside from that the flashings aren't great and if the chimney isn't used some damp could be internal.

Replace step flashing, back gutter, apron,seal with Lead sealant then coat whole of stack with storm dry , job done.

havnt read comments chimneys are built only single skin brickwork if no longer in use never get chance to dry out fully if not in use need to be capped off and air flow introduced most commonly by the addition of air bricks

Could be water going down the chimney pots. A few builders misdiagnosed damp spots around my chimney.. Suggested I needed to scaffold the whole house and take them down. A new £30 cowl fixed it.

I’d say there’s an issue in the leadwork behind the chimney, water is pooling on the plasterboard at the back of the chimney and then running down the side of the chimney, the watermarks tell the story. If the chimney was allowing water to permeate through there would be a more even spread of a visible damp patch and watermarks whereas in this occasion it is concentrated at the back of the chimney and then finding it’s way down the ceiling alongside the chimney.

Look at pic on page 8:09. There you can see each bit of flashing is basically a narrow sheet of lead that barely extends to the left beyond the margin of the next section of flashing. This allows water to creep along in that overlap, then migrate further inwards to the brick. Those sections of flashing should have their entire face be shaped like a triangle with the top going into the mortar, then the next section coming down over it, not leaving unflashed small sections. There lies the source of the leakage problem - bad, incomplete flashing sections..

I lived in a house for 25 years ...had the same problem . Had all the local roofers take a look and spent thousands. Had it repointed ....new flashing and water seal . It was still leaking when I moved house !

We have had chimney scaffold up for two years. Had the pots capped, pointing repaired, stormdry applied. Still a slight damp issue. All the lead looks good. My neighbour and myself are wondering if the lead valleys have become porous. The house is 80 years old. However, it's an ex council property and the council replaced all the roofs in the 70's and sprayed foam insulation into the cavities. Next step is to check all the copper pipes in the loft. Work has been done and we know that in the 70's cheap impure copper was the only tube available and it was contaminated with particles of iron. The iron rusts and small pinholes appear. It's been a nightmare.

The pointing is the issue more than the type of sand and strength they have used. Pointing should sit just under the brick above it and chamfered to create run off. That pointing is trapping rain water at the top of the pointing due to it coming out further than the brick.

My chimney was leaking when it rained due to the bricks being very porous so I tried a version of siloxane yogurt stuff which worked a treat. The bricks in the loft were soaked previously but are bone dry now.

Lots of logical comments been made already, but the colour of the staining indicates mineral contamination which is probably very hygroscopic and possibly will never dry. I’m a damp surveyor and I see this hygroscopic damp problem a lot below old chimneys. I’ve seen perfectly good chimneys removed completely and tiled over, but the damp patch below still never dries. I think it could be part of the issue here.

I think Alan Torrance is spot on with comments about poor quality leadwork. Superficially looks like it has been well done, but actually, due to lack of overlap, amount of lead insertion into joints of the brickwork and insufficient under slate flashing [probably all around the chimney]; in conjunction with excessively protruding jointing of the mortar mix, [being too strong] is undoubtedly a major if not total cause of this. Pay once, cry once.

I could really do with your expertise, I have a problem with my chimney, I have had several people try to fix it, but every winter, sure enough we get some damp on the ceiling, flaking paint on the ceiling, salts coming out of the plasterboard and wall.... definitely want it sorted out, Croydon based here. The chimney is part of an extension that was built in 1996 and has apparently never been right!

The culprit is that pointing job! Someone used a strong mix of cement mortar and cement will retain water for a very long time. Also as @MrDimensionalStone said the pointing is way to strong for the stonework, so it will crack over time and water seeps in. He probably has the same problem in outer walls but insulation prevents from going to inner walls. He should also check the top (flat part) of the chimney. I live in Portugal and for many years people used to restore old houses with granite walls repointing with cement mortar. This led to problems with water ingress and cracking. These days we use lime mortars compatible with the stone.

Hi Roger . One of the potential problems for owners of older properties like me where sand lime mortar jointing dried out excessively due to last years drought . Unfortunately this led to wicking effect . So with the joints getting soaked by rainwater the internal walls can not dry out fast enough during the winter months . We therefore have to wait for the summer months to dry out the rooms .

Roger didn't mention much the other reason that pointing is so bad in this situation- it holds the rainwater. It doesn't alow the water to flow off well so it kind of hangs about on the brickwork much longer than it should. The stack needs everything possible tipped in it's favour if it's not going to leak.

Check,back gutter for leaks,rake out and repoint chimney with weather struck joints,make sure top and corbel course are correctly flaunched,cap and vent any unused flues and maybe hack off internal gypsum plaster and use lime instead? Hope that helps?

As an architect the pattern of damp emanates from the rear of the stack. Ring wind can hold a 100 mm head of water and a lot of water is hitting the back of the stack and running down onto the back flashing. I would replace the back soakers and flashings ensuring the lead has as deep a bed as possible. Then treat the tack with a sprayed waterproofed or render the back face. With waterproof render.

40 years a roofer and i could spot the problem before one minute into this video !

The chimney on the right hand side is also pointed in the same way, Probably a pin hole, or tiny crack in the lead at rear of the stack dripping on to the timber support board beneath. Lead goes thin when beaten to stretch around a right angle ,plus age and degradation. Staining on the ceiling is mainly to rear and tracking down part way.

As the owner of 2 chimneys with a new roof 20 yrs ago, new flashing, pointed ect The problem lies with porous brickwork, Over the years used chimneys can have a lot of constant heat going up through them in all weather conditions, Heat kills bricks, they act like a sponge, When it rains warter flows through the bricks, under the flashing and runs down the chimney breast. Your problem is the bricks ! You need a new chimney

Sometimes the problem with moisture entering at the chimney has nothing to do with the chimney itself. Ridge tiles that let water enter will not be apparent at the ridge because the water runs down the beams and only enters the building when it is forced to do, for example by a chimney. Waterproofing the chimney will not fix the problem and taking the chimney down will only move the problem.

I agree with you, the chimney has had various efforts but attention to detail is the key, the pointing is hard sand/cement (I would use lime mortar) and lead mate in the flashings is good as it dosnt crack with the movement of the lead during temperature change but I would like to see it fill all the joint (look a bit inconsistant/ gappy) as theres no damp course in this I would plumb for sealing it with storm guard or similar and make sure the flaunching is sound on the top with no cracks and fit a vented cap if not in use. You have to remember these bricks have seen it all in terms of "weather battering" and are likley to be very weathered. Chimney is only single skin with a draught going through it (if its an open fire place) so vent it and seal it I aggree. You shouldnt have any more issues. 👍

Worked on these for years. Its the soakers they aren't overlapping they aren't long enough. The flashing isn't overlapping enough too. Agree with the storm dry on these old stone houses they have been up 120 years sometimes every little helps. Should see lead poking out of every slate at the side of the chimney

Cement pointing! Should be lime mortar

First try the Thompson's water seal or some thing similar. If that does not work Then Re lead the stack, Bell cast beads around the base of the stack, scratch coat , render and re flaunch the top of the stack with wash sand cement or if the chimney is not in use then drop it below roof line and felt, batten and slate over the void!

It seems the slabs that join the slates to the chimney (are they called soakers?) are correctly woven in. The lead flashing at the bottom seems too shallow on the vertical part. The water which will flow from the lowest lead counter can now easily creep round the corner and soak the thick point work just above the flashing. Even though the lead counters seem to be spread fairly evenly, at first sight. It may have been better to choose a width and step which isn’t so lined up with the vertical point work. A slightly wider lead counter will have to surpass the adjacent vertical point. The larger overlap can then also be used to better interlock the lead counters at the point where they cover the soakers. With the missing photo of the valley gutter, there’s indeed some important info missing. Whilst looking at the chimney sides in general, the lead counters being to too much inline with the vertical points, and the low placement of the flashing at the bottom, it seems that the lead work has been kept too short ‘upwards,’ for a visual reason perhaps? However, unless our eyes are indeed up close, this visual element can hardly be seen from downstairs. Other than from higher up in the vicinity. That visual pleasantry is misplaced, at least a point higher would be my preferred choice in general. Also for the simple fact that we’re confronted with a significant increase in rainfall. More poignant, from this observation above, the lines to which this chimney has been covered, justify the anticipation that the valley gutter is simply too low as well. When I look at the highest lead counter, there’s hardly an overlap visible, although it is hard to see. What often is the problem with valley gutters, is the way they are installed. Most common mistake I’ve seen has been that the lead of the valley gutter was mounted into the chimney as a flashing. Instead of a separate valley and flashing part. This fixed mounting puts too much stress on the lead and will lead to problems whilst forming the ‘ears’ that need to be driven over and around the slates, lead counters and chimney. Another common mistake is to use a lead that’s too low in thickness. At the very least 35 pounds lead should be used, but up to 60 pound lead should be preferred. 35 pound should suffice in this situation with the slate roof, which doesn’t create such awkward lines to which the lead needs to be formed, to create a long living cover. In all cases correct and appropriate use of the lead batter is an absolute necessity. So much for the lead work, as these chimneys are still in use, the question should also rise what kind of appliances are used on these channels? High efficiency combustion boilers and central heating appliances produce exhausts with much lower temperatures, which produce a significant amount of condensation. That could just as well be a cause of this problem, or it could tip the low quality of the lead work, especially where the moisture from the outside coincides with the possible condensation on the inside of the channel.

Everyone seems to be ignoring the fact the slates are not tied into next doors slates but filled with a bit of muck ! See video. The new felt under the slates would carry the water down and across as their is a side fall. I bet it is just cut around the chimney and not upturned and sealed to shed the water around it.

Great show old man may God richly bless you thanks 😊

When are we going to have a new series, like when we had James. We need a new extension ore a big renovation. Love the channel.

I have exactly the same problem! Six different roofers have not been able to fix it. I have a pet paddling pool in the loft catching the water. Am at my wits end after having so much done by different contractors and paid so much. Fed up. How can so many professionals not know what the problem is!

Quite a few things could be happening there, hard to say from brief pics, but maybe even water flowing along the ridge under the tiles from a neighbouring roof? I think I'd try a process of elimination starting by tying a tarpaulin tight around the chimney to see if the water is really coming from there? Though repeat visits will get expensive for the builder, I suspect, as people like an instant correct answer.

I often find a chimney rebuild with a lead tray. these old stacks were often built without them and were ok while as the damp had a metre or so to dry out in the attic.. the problem cmae when the attic was converted into a room and not allowing the damp from the outside to dry out.

Got a leaky chimney possibly and it’s been given plenty of coatings of modern stuff. Hoping I can get a builder to use lime for rebuilding the chimney.

Possible water ingress around or through the chimney pot. Wind and rain will push water down any gaps. Possibly a cracked or broken or even missing chimney liner due to an chimney fire in the past or dodgy work

There are no caps on 5hose crown type chimneys! The water pours in , hits an internal shelf and there it is , but there's sometimes multiple issues

I used Integral Waterproofer on a 1 to 20 mix in water with my sand, cement and lime. Also a bit of SBR and Rendamix for this external render

Hi Roger, Are the chimneys still open and allowing rainfall to enter? Are the fireplaces closed up? You know the rest. Love the channel

No chimney trays …! Take down rebuild with NHL mortar Redo aprons We have replaced many chimney stacks that didn’t have trays ..usually pre 1930’s in Cardiff wales These damp issues usually come to light when home owners convert the old cold roof attic space into a habitable room…and incorrect finishes applied to chimney breast within the new room

I would go with a transparent water repellant too because it would be the quickest easiest thing to do for a first attempt, and it can't do any harm because no vapour needs to get out from the inside, moisture inside the chimney can go up the chimney to escape. Its a pity that there aren't drones that could do it, I have seen drones with a tank but they are for crop spraying not for accurate nozzle spray.

Warm flue and a cold flue can cause condensation. Have seen that run like a tap before. Not saying its the case here but that one will get you scratching your head. Took a chimney down twice on that one

Quite agree poor leadwork. There are also other issue with this chimney.

Owner of a chimney rebuilding company here in Minnesota. That chimney is leaning bad. The old mortar behind the Tuck-pointing is rotten and probably like powder, which is why it has partially "collapsed" over the years in areas and is so out of plumb. The old mortar behind the tuck-pointing is acting like a sponge and holding water way more than the stone or brick. It will never dry out enough to even properly install a coat of siloxane/sealer on it. There will always be some sort of moisture in the old rotten mortar. You put sealer on and it's not completely dry underneath, you may start to see the the faces of the brick start to spall because now the moisture is trapped behind the sealer and wants to escape, see it all the time with painted brick, the sealers and siloxanes are no different. Could probably demo this chimney with very little effort the mortar, is so rotten. The chimney needs to be torn down and replaced. Could reuse the brick if feasible, we do it all the time. But it needs to be torn down, brick re- installed with new mortar and proper overhanging concrete crown for better water shedding directly off the top of the chimney. Flashing/Reglet should be a minimum of 4" up over the brick on the front and sides and up 8" on the brick on the back. That chimney is in no way shape or form flashed properly, at least by our standards here in the States.

That pointing on the back wall and chimney needs to be inset bucket handle style not sticking up to collect the water dripping down it. It does not need much of crack/hole to allow water in.

I’m a retired roofer and builder and the pointing and lead work is sub standard.

Hi Roger, if this person doesn't use one of these flues they need to make sure it is vented top and bottom or this will cause big problems as the air oassung by helps ti wick the moisture away 😊👍🏻

All the pointing needs raked out to a decent depth removing all traces of cement. Give it a chance to breathe try and do it before a spell of good summer weather. Repoint with 1:3 "NHL(naturally hydraulic lime, compressive strength 5Newtons/mm sq) 5" lime to 3 parts sand, and don't point in that style use a weather struck or slightly recessed finish (and cover with hessian and polythene for a week or so, keep the wind, sun and rain off of it, don't be afraid to peel back the covers and give it a light mist spray with water during this). 38 years time served mason...

Think there's a multitude of problems here. Pointing for one, never had any faith in cement strap pointing. All it does is cause damp and over time, damages brick as we can see in some of the photos. If you visit houses with that kind of pointing, I would wager that all have damp. The stepped lead flashing needs tidying up properly. Do we even know if that flashing is rolled inside the mortar joint or is it just pushed in flat. The apron as you say could have done with being up at least another course. Mortar on lead does not seal effectively as water will travel through the mortar and where the mortar meets the lead. I see something that resembles a join between properties, I would be having a look at that aswell.

I agree with comment below, lead work looks substandard, take the lot off and start again, can spend a fortune on people jumping up there with a mastic gun. A good roofer who can weld lead will have it sorted for good! Just my humble opinion as invited to offer.

either soakers don't start far enough up or back gutter is inadequate ! can't see the pointing being the issue... though it isn't ideal and would be worth weather pointing if you are accessing the chimney anyway.. a brick treatment is a good idea as suggested but I still feel there is a greater problem on the back flashing!

Sounds like very sensible advice to me as all external finishes should allow evaporative drying as you rightly point out. Also he should indeed follow your advice an have the back-gutter checked. If the flues are disused I might also suggest fitting pepper pots to these to prevent rain going down the pots. Rain-hoods would be an alternative if they are in use. That pointing is wrong practically and visually as you say!

Lead work doesn’t look great but I have seen issues where a cracked cap caused issues like this and also had issue with some bricks just absorbing the the water and it’s coming threw them below the lead. Few coats of Thomson’s or a worst case render it with sand and cent with added waterproofer. That’s my personal opinion.