Chimney Stack resting on lintels and gallows brackets

stuart45

That's probably where they came from, laying around in the roof space after combi or megaflo was fitted.

HAWKLANDER

Eldi_Dos said:

Regarding your concern about the brackets, I have seen similar holding up water tanks.

Thanks very much for the info. So is that a good or bad thing? Are they capable of holding quite a weight then, or not really suitable for holding up this bit of the chimney stack? 

HAWKLANDER

stuart45 said:

That's probably where they came from, laying around in the roof space after combi or megaflo was fitted.

Ah ok, so maybe recycled them for this job. Do you know how much a full water tank would weigh in an old Victorian terrace house? I'm guessing quite a bit - I've done some research online but can't find any answers. I'm hoping they are fine for this use too. I've just been in the loft to try and have a look myself and get some more photos, as the picture above was taken by the roofer. I've never been that far back in the roof, so trying to work out where the beams / joists are to walk on. Everything online says I should use boards to walk over it.

weeg

The only way for you to confirm if it's really ok is through either a detailed assessment of the condition of the brackets, the remaining chimney and the wall, or through measurement of the brackets and calculations based on the weight of the chimney and the structural strength of the brackets. Or a combination of both of these. Similarly the weight of an old water tank is a shot in the dark.

At a glance, it doesn't look like it's moving, and has clearly been there for a while, but no-one can really tell based on a couple of photos. The only real way to get peace of mind is going to be to get a structural engineer out. Find a local practice that specialises in domestic work. A roofer is not remotely qualified to decide it's fine.

stuart45

I doubt if an SE will say it's OK, because one of the rules that Building Control use for gallows brackets is that the wall shouldn't be built from lime mortar.
The problem with jobs like this is because of the potential serious consequences of the collapse of the chimney you'd have to be 100% certain it's safe. Allowing something that wouldn't pass Building regs is a risk.

HAWKLANDER

weeg said:

The only way for you to confirm if it's really ok is through either a detailed assessment of the condition of the brackets, the remaining chimney and the wall, or through measurement of the brackets and calculations based on the weight of the chimney and the structural strength of the brackets. Or a combination of both of these. Similarly the weight of an old water tank is a shot in the dark.

At a glance, it doesn't look like it's moving, and has clearly been there for a while, but no-one can really tell based on a couple of photos. The only real way to get peace of mind is going to be to get a structural engineer out. Find a local practice that specialises in domestic work. A roofer is not remotely qualified to decide it's fine.

Thanks very much for your help. Yes I think you're right. I had a surveyor her back in 2019. He says he will pop in next time he is in the area to take a look. If he can't tell me exactly what is going on, then I'll pay out for a SE. Things like this are so annoying as I suppose it could be absolutely fine, but then the thought of a chimney falling through the roof on top of me and my family is terrifying. The problem is the sort of money we've been quoted is the difference between going on holiday or not this year. Thanks again for your input and all your help.

weeg

stuart45 said:

I doubt if an SE will say it's OK, because one of the rules that Building Control use for gallows brackets is that the wall shouldn't be built from lime mortar.
The problem with jobs like this is because of the potential serious consequences of the collapse of the chimney you'd have to be 100% certain it's safe. Allowing something that wouldn't pass Building regs is a risk.

aha! Good to know. There are no such rules here in Scotland. But also the rules here aren't retro-active, so even if you couldn't do it now, if it isn't failing we can judge it to be acceptable. It's a very different system.

Eldi_Dos

Speaking as a unqualified person but from a householders perspective,I would approach your neighbour and see if they would be agreeable to having the stack removed, even if you have to foot a bigger percentage of the bill.Failing that then spend money on getting a qualified engineer in.

I would be wary of any thoughts of diy fix, ie bracing the existing brackets.

GDB2222

I don’t want to be picky about your photography skills, but the whole thing looked less alarming once I turned the photo so the verticals were more vertical! 

A typical water tank these days would store 200 litres, and weigh 200 kilograms. I’m not sure how that helps, as you don’t know what the brackets were used for before?

The risk depends what is underneath the stack if it drops. Is it a bedroom that you use? 50 bricks weigh 100 kilograms, so you can take it from there, allowing for mortar, tiles, the party wall … Those two lintels must weigh a bit!   A few kilos, falling from a height, would cause you a lot of damage, let alone a few hundred. 

silvercar

I would say tread carefully. I had the remnants of an angled chimney stack that was left on ground floor only. With the advice of a structural engineer the chimney stack was removed. All was fine until I walked along the upstairs landing, my foot stepped on what was a slab of the original chimney stack that had no longer had any support underneath. The slab broke, parts shattered and my foot dropped down a few inches. Luckily no lasting damage. Probably the structural engineer should have told the builders to look out for this.