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Circa 1955 craftsman, chimney failure, bricks are turning into soft clay, cap has been bad for a long time. I was thinking of cutting it back and replacing but matching is an issue. Where to start?
Chimney Crumbling above roofline
- Thread starter Dirtmechanic
- Start date
Hi,
First of course DM is safety because of height; a simple slip or mistake could be the last ever made.
Bron and I live in a true detached bungalow with a shallow pitched roof so is reasonably safe to work on.
We replaced the entire roof 18 months after moving here about 32 years ago Bron and I doing the lot. I completely forgot about the chimney other than adding new lead flashing; the chimney stack having no pot being entirely open at it's top. During a terrific storm we suffered water ingress to our front room on the ceiling above the fireplace.
Thinking it to be a simple pointing job I went onto the roof with hammer and chisels and set about removing the old pointing to a depth of an inch; as soon as I hit the chisel with the hammer the entire chimney stack wobbled; the stone like your bricks was now crumbly and highly porous.
This simple pointing job turned into replacing the chimney stack but I also added a new chimney pot. The pot is in two halves; it's very heavy and it's completely sealed to the top but with lots of vents lower down. I used a concrete mix to secure the pot angling it the shed water.
Our bungalow is built in random stone but the local stone suppliers were all on holiday it being Easter time; desperate to get the job done we visited a builders merchant and bought man made stone with a rustic face this surprisingly quite cheap.
The job took about a week to complete and I didn't rush; the chimney has a concrete liner; the new stone though was a bit of a pain to lay due to the outer face not being straight but the end result was well worth it. The new stone is totally different to the original stone but it adds a bit of character with the new pot standing proud.
I'm not a builder DM but taking my time and for once in lovely weather I enjoyed this chimney job; I took great care at every stage not to cause roof damage whilst walking on the roof tiles also removing the old stone was done with care not to drop one of the heavy stones; the patio beneath were I was working was kept clear of people for their safety. I've forgotten the mortar mix I used but I did some research on the web for correct mix; too strong a mortar mix would over the years spall (destroy) the stones and the mortar needs striking off being not proud of the outside faces; a shallow recess is the way to go.
If you can't stand heights don't try to do the job and is it very important to obtain a colour match for the new bricks? Having a safe watertight chimney is the most important?
Do you have a picture?
Kind regards, Colin.
New chimney nearing completion. Please note the top course which are cut paving flags to throw water clear and the concrete bed for the new pot; the flashing is lead. It's worth mentioning the roof ridge tiles are called "modern" and these very seldom get blown off unlike half round ridge tiles. The ridge tiles are fully bedded in mortar but special slip tiles are included otherwise a very thick mortar joint would have been needed. All the mortar was coloured to match the tiles. We've never replaced a roof previously and I spent 18 months researching before proceeding; it paid off but it was hard graft.
What a relief to have this chimney completed and it cost very little regarding materials; the two piece chimney pot was a discontinued line that we bought for little money; the top course was cut from paving flags we already had the new stone was cheap.
New pot base in close up bedded in concrete for security against the high wind we suffer here on the valley side.
Of course my constant companion Blackie was ever near just wanting to wash all the mortar from the joints so each day as work finished I added waterproofing.
I was amazed by the unsafe condition of our chimney; it looked fine from the ground; why mess around with something like this; it's quicker and better to completely replace it but as I say safety on a roof is absolutely paramount.
Here's one way to remove a chimney; the late Fred Dibnah in action; Fred lived the other side of The Pennines from us.
First of course DM is safety because of height; a simple slip or mistake could be the last ever made.
Bron and I live in a true detached bungalow with a shallow pitched roof so is reasonably safe to work on.
We replaced the entire roof 18 months after moving here about 32 years ago Bron and I doing the lot. I completely forgot about the chimney other than adding new lead flashing; the chimney stack having no pot being entirely open at it's top. During a terrific storm we suffered water ingress to our front room on the ceiling above the fireplace.
Thinking it to be a simple pointing job I went onto the roof with hammer and chisels and set about removing the old pointing to a depth of an inch; as soon as I hit the chisel with the hammer the entire chimney stack wobbled; the stone like your bricks was now crumbly and highly porous.
This simple pointing job turned into replacing the chimney stack but I also added a new chimney pot. The pot is in two halves; it's very heavy and it's completely sealed to the top but with lots of vents lower down. I used a concrete mix to secure the pot angling it the shed water.
Our bungalow is built in random stone but the local stone suppliers were all on holiday it being Easter time; desperate to get the job done we visited a builders merchant and bought man made stone with a rustic face this surprisingly quite cheap.
The job took about a week to complete and I didn't rush; the chimney has a concrete liner; the new stone though was a bit of a pain to lay due to the outer face not being straight but the end result was well worth it. The new stone is totally different to the original stone but it adds a bit of character with the new pot standing proud.
I'm not a builder DM but taking my time and for once in lovely weather I enjoyed this chimney job; I took great care at every stage not to cause roof damage whilst walking on the roof tiles also removing the old stone was done with care not to drop one of the heavy stones; the patio beneath were I was working was kept clear of people for their safety. I've forgotten the mortar mix I used but I did some research on the web for correct mix; too strong a mortar mix would over the years spall (destroy) the stones and the mortar needs striking off being not proud of the outside faces; a shallow recess is the way to go.
If you can't stand heights don't try to do the job and is it very important to obtain a colour match for the new bricks? Having a safe watertight chimney is the most important?
Do you have a picture?
Kind regards, Colin.
New chimney nearing completion. Please note the top course which are cut paving flags to throw water clear and the concrete bed for the new pot; the flashing is lead. It's worth mentioning the roof ridge tiles are called "modern" and these very seldom get blown off unlike half round ridge tiles. The ridge tiles are fully bedded in mortar but special slip tiles are included otherwise a very thick mortar joint would have been needed. All the mortar was coloured to match the tiles. We've never replaced a roof previously and I spent 18 months researching before proceeding; it paid off but it was hard graft.
What a relief to have this chimney completed and it cost very little regarding materials; the two piece chimney pot was a discontinued line that we bought for little money; the top course was cut from paving flags we already had the new stone was cheap.
New pot base in close up bedded in concrete for security against the high wind we suffer here on the valley side.
Of course my constant companion Blackie was ever near just wanting to wash all the mortar from the joints so each day as work finished I added waterproofing.
I was amazed by the unsafe condition of our chimney; it looked fine from the ground; why mess around with something like this; it's quicker and better to completely replace it but as I say safety on a roof is absolutely paramount.
Here's one way to remove a chimney; the late Fred Dibnah in action; Fred lived the other side of The Pennines from us.
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@Dirtmechanic - I know you are a pretty handy person so I am going to make a suggestion for you. Are you able to remove the upper bricks safely? I would go down until you come to solid bricks and mortar. See if you can get enough of the old bricks that are solid to make a couple layers. If this is possible, get a brick color to compliment the original color and build it back up with these bricks. Then cap it off with the old bricks. It should look good and not look like a patch job. Be sure to put a waterproofer on the end job to prevent future problems.
Note. Colin’s excellent post wasn’t on here when I wrote this.
Note. Colin’s excellent post wasn’t on here when I wrote this.
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Hi,
Excellent suggestion Doug.
I'd use engineering bricks for a chimney these being so exposed to severe weather conditions.
https://en.wikipedia.org/wiki/Engineering_brick
Our garage now workshop suffered water ingress for many years until the job came to the top of the list and I attacked it; I replaced original foundation porous bricks with engineering bricks and I added a plastic conduit drain allowing any water gaining cavity access to be discharged harmlessly onto our driveway but I did make good the entry where the water was getting in so the new drain was an additional measure I dreamt up. I gave the job a great deal of thought and lots of research; I found I could buy waterproofing mortar additive so thought what a great idea; now we have engineering bricks and waterproof mortar; job well sorted; I must have solved the water ingress because the end of the new conduit drain is always dry but it's there just in case. I've never seen such a drain added to the base of a wall.
Kind regards, Colin.
Soaking wet foundation course of bricks.
New sealing tape (Flashband) and new conduit drain; the conduit has many holes drilled into it allowing any future water to enter and be discharged harmlessly onto the driveway.
Very hard work spanning a number of days because only three brick lengths were removed at a time before new bricks were added and the mortar allowed to set for a day; this is a difficult procedure and to get it wrong could mean wall collapse. It's all now dried out and new benches have been installed I admit I go way over the top but with thought I can usually improve upon the original.
Excellent suggestion Doug.
I'd use engineering bricks for a chimney these being so exposed to severe weather conditions.
https://en.wikipedia.org/wiki/Engineering_brick
Our garage now workshop suffered water ingress for many years until the job came to the top of the list and I attacked it; I replaced original foundation porous bricks with engineering bricks and I added a plastic conduit drain allowing any water gaining cavity access to be discharged harmlessly onto our driveway but I did make good the entry where the water was getting in so the new drain was an additional measure I dreamt up. I gave the job a great deal of thought and lots of research; I found I could buy waterproofing mortar additive so thought what a great idea; now we have engineering bricks and waterproof mortar; job well sorted; I must have solved the water ingress because the end of the new conduit drain is always dry but it's there just in case. I've never seen such a drain added to the base of a wall.
Kind regards, Colin.
Soaking wet foundation course of bricks.
New sealing tape (Flashband) and new conduit drain; the conduit has many holes drilled into it allowing any future water to enter and be discharged harmlessly onto the driveway.
Very hard work spanning a number of days because only three brick lengths were removed at a time before new bricks were added and the mortar allowed to set for a day; this is a difficult procedure and to get it wrong could mean wall collapse. It's all now dried out and new benches have been installed I admit I go way over the top but with thought I can usually improve upon the original.