Enlarging the chimney space

Laura99

Hi,

I was hoping that someone could help. I am wanting to enlarge the opeing of our chimney breast to insert a range cooker. It already has one in now but the gap above it is too low and an arch. I wanted to open it up above by about 2/3 foot at put an RSJ in so that it is square. There is a chimney stack on the above 2 floors.

I am not sure who I need to speak to about doing this, ie, do I need a structural engineer or can I do this my self (which help from someone who has some building experience as well, obviously) ?

Also how much is an RSJ likely to cost? It would be roughly 1.5/2 metres.

Would really appreciate anyones thoughts, as all I can seem to find out about is removing a supporting wall.

Thanks
L

deano72_2

iv just done something simaular.i knocked back to back fireplaces into one..with instruction from my ol man who is a builder.

it was fairly simple.i knocked the fireplace through & didnt need an acro as it was well suported due to the angle of the chimneys/flues (bit hard to disscribe)then knocked a hole so i could slide a concrete lintel in...i suspect in your case if you knock out where the lintel is to go, then install the lintell,then you can remove the bricks below the lintel which you want removed..but i would get advice from a builder fisrt if i was you.
you can buy lintels from builders merchants,mite not be your size but then you would have to cut it with diskcutter to suit

Laura99

Thanks, you make it sound so easy! A concrete lintel sounds good, I think they are cheaper aren't they?

I'm having the chimneys swept so I will ask them what angle they are.

Thanks again

Kiran

Thats quite a lot of brickwork to be held up by a concrete lintel over a 2m span. You have a couple of options with regards the lintel, get a structural engineers calculation for the lintel (which will also be required for building regulations) or if you can be certain of what the wall is made up of and you are happy to measure up you may be able to find a lintel manufacturer who will do the calcs for you. Probably cost less than a structural engineers calcs but they wll go on information provided by you and not their own analysis. More risky on the PI front if something goes wrong

The job itself isn't difficult, but requires knowledge of using supports (either acro props or strongboys etc). It will be a very messy job and and requires plasterwork to be repaired.

It also requires a lot of care as an error could be catastrophic. As a reference, a cubic metre of brickwork weighs 2.4t!

It really is a job for a pro unless you have someone who is 100% certain of what they are doing.

Good luck and hope this helped

Laura99

Thanks, it definately helps.

I think I will go with the RSJ just to be safe! My brother has a book that has the calculations for load bearing walls and has some acro props, so hopefully we'll be o.k.

In terms of the building regulations, do we need to get the work approved by anyone then?

Thanks

macman

Yes, you need your LA building control approval, and you will need to serve a Party Wall Notice if it is a party wall.

Kiran

Laura99 wrote: »

Thanks, it definately helps.

I think I will go with the RSJ just to be safe! My brother has a book that has the calculations for load bearing walls and has some acro props, so hopefully we'll be o.k.

In terms of the building regulations, do we need to get the work approved by anyone then?

Thanks

As macman says, you will need building control approval and this is where the calcs come into play. You'll probably be alright on the party wall front as I assume the only party wall present will be the one at the back of the chimney which will remain untouched?

Once you have decided on the exact job you want to do, ring your local authority building control and talk it through with them, they will tell you exactly what you will need to submit and the cost. Usually £150.

Let us know how it goes