Chimney breast

[phattanglo]

I hope my first post makes sense and that someone will be able to help.
I am opening up a chimney breast to take a range cooker and would like to know what size steel to put in.
It will be resting on the breast sides with a span of 1700mm.
It will be at ceiling height supporting the end of two ceiling joists and the upstairs hearth stones.

I also need to bridge a two metre wide section with an RSJ this will be from the top of a supporting wall to an external wall.
There will be no brickwork above as it will be directly below the ceiling joists.
Could you please recommend the correct size and weight of RSJ.
Cheers Kev.

 

[tony1851]

Something like a 152x89 would be fine; it will also fit in with your brick courses.

 

[phattanglo]

That's a big help thanks.

 

[dann09]

I think that there is perhaps a little more than meets the eye in your post. Then again, as i try to visualise your post, perhaps i'm wrong.

Are you removing a panel of brickwork 1700mm wide by up to ceiling height, with some brickwork left in at either side to bear the lintel?

The lintel will support two "trimming joists" (if they are trimming joists) and the stone front and back hearth, and the remaining c/breast above it? Have i got it right?

Thing is, with trimming joists, they usually go past either side of the c/breast and land in the wall behind.
Or, do you have the arrangement where joists run into the c/breast itself?

It's important that you know how your c/breast and hearth are carcassed/framed before work starts.

 

[joe-90]

I think that there is perhaps a little more than meets the eye in your post. Then again, as i try to visualise your post, perhaps i'm wrong.

You usually are.

 

[tony1851]

I think that there is perhaps a little more than meets the eye in your post. Then again, as i try to visualise your post, perhaps i'm wrong.

Are you removing a panel of brickwork 1700mm wide by up to ceiling height, with some brickwork left in at either side to bear the lintel?

The lintel will support two "trimming joists" (if they are trimming joists) and the stone front and back hearth, and the remaining c/breast above it? Have i got it right?

Thing is, with trimming joists, they usually go past either side of the c/breast and land in the wall behind.
Or, do you have the arrangement where joists run into the c/breast itself?

It's important that you know how your c/breast and hearth are carcassed/framed before work starts.

It may seem a considerable weight at first glance, but a 6x3 1/2 will easily span that short distance.

 

[dann09]

Tony,

I'm sure that it will.
My post wasn't doubting what you had recommended, but more a questioning of what exactly the OP was intending to support.
And what he was going to have to work with.

 

[phattanglo]

You have it pretty much right. with the exception of the joists.
The joist is basically a full length except for a section cut out in the middle of the breast where the upstairs hearth stone sits directly onto the top of the breast front.
So it's joist, hearth stone, joist all in line with and resting on the top of the chimney breast front.

 

[dann09]

I still can't fully visualise the situation, and i wouldn't want to give advice based on an incomplete understanding.

You could google up some diagrams of floor joisting around a c/breast, i'm sure that they are out there, and compare them with what you've got?

Perhaps you will post a scanned sketch of what you have or pics?
Or, maybe you feel confident in going ahead on the basis of Stuart's info?

 

[tony1851]

I still can't fully visualise the situation, and i wouldn't want to give advice based on an incomplete understanding.

You could google up some diagrams of floor joisting around a c/breast, i'm sure that they are out there, and compare them with what you've got?

Perhaps you will post a scanned sketch of what you have or pics?
Or, maybe you feel confident in going ahead on the basis of Stuart's info?

I wonder if we're getting bogged down a little on the layout of the joists and hearth.
Usually the hearth slab is partly supported off the projecting breast below, and partly off the 1st joist, which is often thicker than the rest.
But that shouldn't affect how he fixes the steel beam below. A single well-positioned prop would take the weight sufficiently to get the steel in.

 

[dann09]

tony, forgive me for getting your name mixed up with Stuart's. I'm trying to do two things at once, and getting them both in a muddle.

Your right, i'm sure, but i still have a vague idea, based on the first post, that the OP wont have an adequate bearing for the lintel.

 

[tony1851]

tony, please. please. PLEASE forgive me for getting your name mixed up with Stuart's. I don't know what came over me! It's a dreadful mistake, I know, and I didn't want to hurt your feelings!! I really must get a grip on myself! By the way, I think your posts are great and I don't think this forum would be half as good if it wasn't for your excellent advice! Keep up the good work, and sorry again for any slight, which was entirely un-intentional!

Your right, i'm sure, but i still have a vague idea, based on the first post, that the OP wont have an adequate bearing for the lintel.

No problem, just watch it in future!

 

[phattanglo]

I've remove a few bricks in the centre of the breast and established an rsj should support everything.
However that is not taking into account the mid feather which I feel is the main consideration in this project.
Would I be right in thinking that I will need lintels to support both the front and the back of the breast with a steel plate or even a third rsj between them to support the full depth of the mid feather.
Although my initial post indicated my intention to put the rsj in at ceiling height I would state that it is not absolutely vital, I just need head clearance above the oven and I am happy to put the steel in at whatever height makes the job easiest.

 

[tony1851]

I've remove a few bricks in the centre of the breast and established an rsj should support everything.
However that is not taking into account the mid feather which I feel is the main consideration in this project.
Would I be right in thinking that I will need lintels to support both the front and the back of the breast with a steel plate or even a third rsj between them to support the full depth of the mid feather.
Although my initial post indicated my intention to put the rsj in at ceiling height I would state that it is not absolutely vital, I just need head clearance above the oven and I am happy to put the steel in at whatever height makes the job easiest.

You should find that the mid-feather is bonded to the front of the chimney breast and the wall at the rear.