Builder advice - bulging chimney

[BoltonSte]

We live in a 230yr old stone terrace, and it has a bulge on the chimney, next door have just converted their loft and this has come up twice now.

1. Their roofer saw it and said it could do with doing, could last 6 months could last 60 years.
2. They've been getting some water through and have noticed that 'their isn't any pointing on one side', although this is from their roofer so I don't know what it means yet.

Now when we had our loft converted a couple of years back, our builder said it could do with pointing, but he'd seen worse and it can be sorted any time we want - wasn't concerned about the bulge. I think it's probably leaking now due to the banging from next door disturbing mortor. As this has been mentioned twice I really think I need to do something about it, I'm going up this weekend to take a look.

Am I right in thinking, that if there is no loose stonework I can just point it all up? If there's loose stones (besides on the crown) then it'd probably need rebuilding? It's a 4 potter if that makes a difference and one pot is used but has a liner in.

Cheers
Ste

I have no experience working with stone tbh or buildings of that age but i can offer this advice.
If the chimney did fail, which they can especially in bad weather / high winds, it would make a lot of damage and be potentionally dangerous.

Get a structual engineer to look at it, will bode well in future too when you come to sell it.

Pointing has to be done properly, 'buttering' up the joints isn't good enough, raking out to at least 20mm and redoing with a strong mix with plasticiser ( or lime additive as it probably was originally) so it lasts.

I think mr skeetly on here has more experience on these type of buildings ( dunno how I know this and could've made it up lol) so he might be able to give you more specific advice.


Phil

[BoltonSte]

Well I've been up today and it's all solid but it is in dire need of a repoint. IPM'd skeetly but I'm just trying to get hold of a roofer to sort it now.

If it's just repointing then you need a brickie not a roofer, as long as they mind working up there.

You got scaffolding up or using a cat ladder?

[andrewsmith]

Ste

Got a picture of the said Chimney.
Sound like sulphate attack of the lime/ cement. It would require a full rebuild and a lining put into the chimney

[BoltonSte]

Originally Posted by specialone

If it's just repointing then you need a brickie not a roofer, as long as they mind working up there.

You got scaffolding up or using a cat ladder?

Another neighbour works at a stone restoration place so he is asking some of their pointers, but it depends on if they are happy being up there.

I used next doors scaffold to get up there yesterday, but that may be going soon, so it'll depend on what they want (I may get the scaffolding to stay a while yet)

Originally Posted by andrewsmith

Ste

Got a picture of the said Chimney.
Sound like sulphate attack of the lime/ cement. It would require a full rebuild and a lining put into the chimney

No pictures I'm affraid. The mortar that was there was solid, but there were some cracks and bits missing, but I think it may have been repointed (if not well) in the past. Wouldn't sulphate attack leave it brittle/sandy/gone?

tbh it's not much of a bow, but next door have heard 'it may go' so are worried, I don't really like them, so maybe I should leave it/give it a push next time it's windy

Thankfully it already has a lining for the multifuel stove, so if it needs a rebuild then so be it.

[andrewsmith]

Originally Posted by BoltonSte

Another neighbour works at a stone restoration place so he is asking some of their pointers, but it depends on if they are happy being up there.

I used next doors scaffold to get up there yesterday, but that may be going soon, so it'll depend on what they want (I may get the scaffolding to stay a while yet)



No pictures I'm affraid. The mortar that was there was solid, but there were some cracks and bits missing, but I think it may have been repointed (if not well) in the past. Wouldn't sulphate attack leave it brittle/sandy/gone?

tbh it's not much of a bow, but next door have heard 'it may go' so are worried, I don't really like them, so maybe I should leave it/give it a push next time it's windy

Thankfully it already has a lining for the multifuel stove, so if it needs a rebuild then so be it.

It may have been repointed with cement mortar instead of Lime mortar (as lime breathes and expands/ contracts with the stone). With stone the bulk of the damage will be internally to the chimney as is affects it from the inside.

This link should explain whats happening a bit better
http://www.buildingconservation.com/...es/chimney.htm

If its a shared chimney (as it sounds to me) speak to your neighbour and see if they're intending to have their side rebuilt.