chimney breast errosion

[Lostdog]

Could i get some advice on this please, some/quite a few of the bricks in my chimney breast are turning to dust, im assuming some kind of reaction with soot in the chimney and the bricks?

the house is just over a hundred years old and the fire place's, mine and next door have not been used for at least 12 years.
thanks

 

[PropRepairAdvice]

Looks like leaks from above have caused some dampness to affect the bricks and mortar. Deal with the leaks and if intending to use the fireplaces get a chimney sweep in with cctv to inspect the flues.

 

[Lostdog]

OK cheers mate, so your saying this is water damage? My neighbour had chimney stack pointed and all the pots changed a few years back, but looks to me they were never capped off.

OK iv just had a search for damp bricks and found it called spalling, the fireplaces won't be used again, so first job cap the pots, replace the really damaged bricks with engineering brick I guess? And can I just render over the rest of it?

I dont know how chimneys are constructed so is it safe? , I'm assuming the neighbour has similar in their attick, but don't live there so hard to check

 

[PropRepairAdvice]

From the pictures supplied yes. If the pots were removed but the flues left open, rainwater can get down the flues. Ideally if capped with for example concrete slabs, really you should have airbricks within the stack to allow ventilation to the flues.

If the flashings look old, then water ingress can occur around them.

If you have chimney pots, fit ventilated cowls.

If rendering the exposed stack, use a lime render rather than cement. It’s breathable.

Replace all missing and spalled bricks. I shouldn’t worry about rendering the stack with the roof void, not necessary.

If you’ve blocked up your breasts in the bedrooms and living rooms, ensure you install a vent in the breasts to allow ventilation in to the flues to prevent condensation.

Any works to shared stacks should have a party wall notice.

have a look at the sweepsafe and competent roofer websites for more info.

All the best.

 

[Lostdog]

From the pictures supplied yes. If the pots were removed but the flues left open, rainwater can get down the flues. Ideally if capped with for example concrete slabs, really you should have airbricks within the stack to allow ventilation to the flues.

If the flashings look old, then water ingress can occur around them.

If you have chimney pots, fit ventilated cowls.

If rendering the exposed stack, use a lime render rather than cement. It’s breathable.

Replace all missing and spalled bricks. I shouldn’t worry about rendering the stack with the roof void, not necessary.

If you’ve blocked up your breasts in the bedrooms and living rooms, ensure you install a vent in the breasts to allow ventilation in to the flues to prevent condensation.

Any works to shared stacks should have a party wall notice.

have a look at the sweepsafe and competent roofer websites for more info.

All the best.

Thank you for the info much appreciated