Opening up a Chimney Breast

[stuart45]

The slate would give the first liner something to sit on, but once the space between it and the brick flue has been filled with mortar it will be held in place with that. Nowadays a cement/vermiculite mix is used.
Are you getting a HETAS fitter in to drop a stainless steel liner down and fit the wood burner using a stove pipe?

 

[Craig-H]

The slate would give the first liner something to sit on, but once the space between it and the brick flue has been filled with mortar it will be held in place with that. Nowadays a cement/vermiculite mix is used.
Are you getting a HETAS fitter in to drop a stainless steel liner down and fit the wood burner using a stove pipe?

That makes sense, thanks for the info.

This is where it all started. I did have a HETAS engineer come and assess the work, but he wasn't interested because of some of the complexities. One of which is overhead power cables running close to the property, so he couldn't get a cherry picker up to the property and he said scaffolding would add another £1,000 on to the job. I found a way to get up to the chimney out of a velux window, so I'm confident I can line the chimney myself. I'll get my son to help feed it out of a secondary velux window. Of all the jobs, this is the one I'm least worried about.

I'm going to knock some bricks out as you suggested as soon as I have time this week.

 

[stuart45]

If you get the liner down will the HETAS fitter connect up the flue and stovepipe to the wood burner and test it, or are you going to DIY and go through Building Control?
Looking at the photos again, I reckon that as they built the back wall first as the structural wall to take the load from above, making alterations to the jambs and even making the lintel higher should be easier. It's looks like they might have a few floor joints resting on the downstairs chimney breast brickwork though.

 

[Craig-H]

I was planning on going the DIY route and documenting everything as I go, then either a HETAS engineer could sign it off or the local council will for £250.

I just went upstairs and checked and the joists aren't resting on the chimney breast, there's about a 20mm gap between the two.

Well it would be a really good outcome if I could widen the opening with a longer lintel. Are you suggesting increasing the height of the lintel might remove the need to remove the first leaf of the back wall - to gain clearance for the flue?

 

[stuart45]

The stove pipe needs to go at 600mm straight up vertically, so getting the lintel higher should help. One tip about flue liners that you probably won't need, is that if they aren't secure and likely to drop down if you remove any support, you can drill a long masonry drill bit through the bottom one and leave it in until you have finish the work below and supported them again. It doesn't matter about the holes in the liner if you are dropping an S/S one down.

 

[cdbe]

I'd quite happily remove a half brick from either side of that, the remaining masonry will be more than adequate. My preference for removing the bricks at the back would be a second lintel and as said, a bit higher wouldn't hurt. I think you need to open it up quite a bit more to get a better idea what's going on, in particular the relative stove and flue positions.

You should be able to install both lintels separately without any propping.

 

[Ivor Windybottom]

I'd quite happily remove a half brick from either side of that, the remaining masonry will be more than adequate. My preference for removing the bricks at the back would be a second lintel and as said, a bit higher wouldn't hurt. I think you need to open it up quite a bit more to get a better idea what's going on, in particular the relative stove and flue positions.

You should be able to install both lintels separately without any propping.

A good lesson in why you shouldn't take structural advice from random strangers on the internet!

 

[Craig-H]

The stove pipe needs to go at 600mm straight up vertically, so getting the lintel higher should help. One tip about flue liners that you probably won't need, is that if they aren't secure and likely to drop down if you remove any support, you can drill a long masonry drill bit through the bottom one and leave it in until you have finish the work below and supported them again. It doesn't matter about the holes in the liner if you are dropping an S/S one down.

That's a good tip - thanks.

 

[Craig-H]

I'd quite happily remove a half brick from either side of that, the remaining masonry will be more than adequate. My preference for removing the bricks at the back would be a second lintel and as said, a bit higher wouldn't hurt. I think you need to open it up quite a bit more to get a better idea what's going on, in particular the relative stove and flue positions.

You should be able to install both lintels separately without any propping.

Thanks... I think you're right about the jambs... It looks like the front 200mm of the chimney breast on the ground floor isn't load bearing from the above, but the back 200mm certainly is. This picture of a party wall chimney breast hopefully illustrates what I mean.

Additionally, if you look at the width of the chimney breast on each floor, it looks like the ground floor breast just encapsulates the structure highlighted in the photo below.

2nd floor - 890mm
1st floor - 1020mm
Ground floor - 1250mm

Ignore widening it for the moment, but in aid of removing 100mm at the back, where would you put the lintel?

 

[Craig-H]

A good lesson in why you shouldn't take structural advice from random strangers on the internet!

It's just someone's opinion, ultimately I am responsible for my actions and decisions. You are also some random stranger on the internet!

 

[cdbe]

in aid of removing 100mm at the back, where would you put the lintel?

As said, you need to open it from the front, establish what's going on inside, what can be removed and what needs supporting. I presume you've done your measuring to ensure you retain 200mm of masonry between you and next door, otherwise you could consider building out the front to make the recess deeper.

This is my favourite (extreme) example of what you might find!