Chimney Stack resting on lintels and gallows brackets

HAWKLANDER

We have just had a builder in our loft who ha said he has serious concerns about our chimney stack. We aren't sure whether to be really concerned or not and would really appreciate some information and advice.

We live in a victorian terraced house in Southsea. This is the rear chimney stack and the breast has been removed from both floors in our house. The chimney breast comes down into the loft and is resting on two linels which are resting on two brackets. This work was done before we moved in so we didn't get it done outselves.

The builder says the brackets are wall brackets and that he isn't sure how they got away with doing it that way, he also says they are bowing away from the wall. He says there are 500 to 700 bricks above it and that it will give way at some point, but can't say when.

I have obviously done extensive research online about what he is saying. I can see that gallows brackets and lintels are used quite commonly to hold up chimney stacks after the breast is removed, ot at least they used to be. I can't really see them bowing away from the wall from the picture. I have counted the bricks from the photos and am not sure there is anywhere near 500 bricks above it even if I count double thickness.

The wall is a party wall with next door. I have read up that it should be 225mm thick. Next door have their chimney breast in place all the way down to the ground.

I am thinking of getting a structural engineer to come in, but the cost is pretty high, so thought I would get some opinions on whether this is really a concern, or whether it is a builder trying to scare us into paying him for an extra job.

Would you please let me know your opinions and what you think of the photo and the size of the chimney stack above. Any info would really be appreciated.

Thank you!

stuart45

This will give you an idea of the number of bricks in a 4 flue stack.

HAWKLANDER

Thanks very much Stuart, this is really helpful! Based on this, it looks like it would be single thickness and about 5 bricks per level. I've counted the rows of bricks in both pictures and I'm guessing there must be about 70 to 80 bricks all together, not the 500 to 700 bricks the builder has said. This isntantly sets off alarm bells on his competency. 

He said there is bowing, and I tihnk he means the wall. This is a party wall between us and next door. From the picture it looks like there is a slantling line of bricks to the side of the breast bricksm but to me the bricks in the breast look ok on the lintels. The lintels looks straight as anything across between the brackets.

Does anyone know if these are normal gallows brackts, or are they cheaper brackets not up to the job? All the gallows brackets I have seen online since researching look a bit different with a right angle extra line to the main right angle and also on the diagonal support bar. That said, these do look substantial. I'm not sure whether to pay out for a structural engineer or if there is nothing to worry about in this situation..

Eldi_Dos

Would your neighbour be interested in sharing the cost of having the stack removed?

stuart45

HAWKLANDER said:

Does anyone know if these are normal gallows brackets, or are they cheaper brackets not up to the job? 

They look too long, so I doubt they were designed for this job.

HAWKLANDER

Eldi_Dos said:

Would your neighbour be interested in sharing the cost of having the stack removed?

I'm not sure, I'll have to ask them. They have their chimney breast still instact down through the house, so they don't have a need to get this done. i guess we would have to remove the whole chimney as it is shared. I really don't want to put much money into this as we don't have much. My ideal solution would be to reinforce the brackets or have a new solution of supporting the stack, if the current set up with brackets and lintels is not sufficient.

HAWKLANDER

stuart45 said:

HAWKLANDER said:

Does anyone know if these are normal gallows brackets, or are they cheaper brackets not up to the job? 

They look too long, so I doubt they were designed for this job.

Thanks again, Stuart. Yes they look like they stick out further than other gallows brackets I have seen online. I wonder if this means they won't be sufficient to support the stack? I guess it is only half the chimney stack on our side, the other side is supported by the chimney breast. It also looks like it doesn'y stick out too far from the main wall, plus the bricks stop before they get to the support diagonal bar on the brackets. Can you see any bowing of the main wall?

stuart45

It's not the best job, as they've left some of the brickwork in below the brackets, instead of taking them out and making good the party wall. Normally use 3 lintels as well.
On the plus side, it's not a tall chimney stack, next door has all theirs in place, and you do have some support. Some people have got them left hanging in the loft.  The gallows brackets have got plenty of bolts into the wall, and it doesn't look like it's pulling away.
An expensive solution is to have a steel put in sitting on load bearing walls, and the brickwork built back up off the steel to the bottom of the chimney.

HAWKLANDER

stuart45 said:

It's not the best job, as they've left some of the brickwork in below the brackets, instead of taking them out and making good the party wall. Normally use 3 lintels as well.
On the plus side, it's not a tall chimney stack, next door has all theirs in place, and you do have some support. Some people have got them left hanging in the loft.  The gallows brackets have got plenty of bolts into the wall, and it doesn't look like it's pulling away.
An expensive solution is to have a steel put in sitting on load bearing walls, and the brickwork built back up off the steel to the bottom of the chimney.

Thanks Stuart, that gives me some reassurance, which is really great. I guess two thirds of the chimney is sat on the party wall and the chimney breast next door. So just a third resting onto these lintels and brackets. I guess the mortar will hold it together to some extent too?
I thought the same thing about there being lots of bolts. I'm not too bothered with bricks being left under the brackets if it asthetic, as it is right at the back of the loft and out of sight.
The main thing for me is that it is not imminently going to fall through the ceiling. The builder sent me messages giving the impression it is in a very dangerous state right now, and has scared the life out of me and my family who are now worrying about the ceiling falling in.
I had a survey done on the house in 2019 and they said it looked fine then and that it had sunstantial brackets supporting the stack. He is going to come back next time he is the area to have another look and confirm, but wanted to get some unbiased views here too.
I am worried if I get builders over to look at it, they will all give us the horror stories and be pitching for work.

stuart45

If you've got any concerns, a Structured Engineer is the best person for an unbiased professional opinion. They might not be as expensive as you think.
If next door ever want to take their chimney breasts down, then you may as well remove the stack as well.

Eldi_Dos

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