opening the chimney breast up

[HoodedClaw]

Hi,

Ive a chimney I want to open up to take a wood burner, only the current and i think original opening is only 20" across , the lintel being only 1/2 a brick wider than this either side, the chimney is 48" wide.

I'd like to put in a new lintel and widen the cheeks out by at least 8" only the problem I'm pondering is that the throat goes right to left and then right again rather than back to front. I've no idea how it is supported.

will i need to access and lintel front to back under the throat as well? is that acceptable?

and would i need building regs round for this?

Thanks, Antony

 

[stuart45]

Can you put a photo on please?

 

[HoodedClaw]

Hi, sure i can, now where did i leave that hosting site....

Looking through, it looks similar to //www.diynot.com/forums/viewtopic.php?t=187253 and answered by noseall, only one course thick over the throat lintel, just not sure how to handle the throat.

At the moment I'm thinking.. remove the lintel and row of bricks below it, place longer throat lintel one row lower and 2 small ones front to back to support the throat and brickwork above the current jambs?(cheeks) at the level of the current lintel and tie that into the back/shared wall.

The house is 1930/40's we think, ex government and very solid, semi. looks mainly like engineering bricks, solid right through.

The lintel is where the throat starts right to left.

Showing the lintel and throat, someone hacked the bricks previously but otherwise looks original.

Taken laying on floor up, to show lintel and throat

Closer on the throat - where is the support? If I'm having a liner put in, would it be removed anyway?

Thanks for your help, Antony

 

[stuart45]

HoodedClaw,
I've taken a few pictures from one of my old books which may help you.
[GALLERY=media, 16306][/GALLERY]
[GALLERY=media, 16307][/GALLERY]
[GALLERY=media, 16308][/GALLERY]
The gather is supported by the brick jambs which are the main structure of the chimney. In theory all the brickwork of the gather will be tied into the jambs and the party wall, so half a brick each side should be OK, although you might lose some of the gather. If you are using a liner rather than a register plate in the gather it won't really matter.

 

[Steve]

Whats a coring hole? Sorry to butt in.

 

[stuart45]

Steve,
A coring hole was left out so a board known as a coring board could be placed inside and catch any falling mortar which would tend to collect at the bend in the flue and block it. The hole would be filled in later.

 

[HoodedClaw]

thanks Stuart45, most useful, after some more research I'm going to put in a larger throat lintel and 2 smaller ones front>back to hold the inner stack over the current jambs and take the jambs and front out about 10", build up the new jambs and just need to decide whether to corbel the bricks at the top or fireboard it square..

when i say i, i do of course mean my part time brickie doing the rebuilding (I'm only good for taking it down) ;o)

Then lime mortar the inside and leave it 'rustic' rough finish, should deal with the heat better than plaster.

Still not sure if I need building regs round, but I'll give them a call - if anyone knows?

Cheers, Antony.

 

[stuart45]

Building Regs are required for woodburner installation unless put in by a HETAS engineer.

 

[HoodedClaw]

yep, I'm getting it fitted by one to avoid that - i meant widening the opening in the breast, new lintel and all..

 

[HoodedClaw]

Hi,

Building regs submitted, putting in a 1000x140x100 prestressed lintel and the 'W' steel ones for the cheeks.

I'm going to use VITCAS HEAT PROOF SCREED to render the inside, but what do i then paint it black with? I'll check if I can add dye to the screed to make it black. If not - is there a non gloss paint I can use on the render? Its a wood burner going in.

thanks, Antony.

 

[stuart45]

Antony,
Glad to see that you are using extra lintels. Always best to be safe.
You will find that dyed mortar will fade so make it really black.
You can get special woodburner black spray paint. You probably could use this on the screed as it resists heat well. I have used it over fire cement no problem.

 

[HoodedClaw]

Work in progress - for anyone planning to do the same...

Acro and strongboy in place just taken after knocking the old lintel out and enlarging for the new one - I wouldn't have bothered with the acro if there was a constructional lintel - you can see where i chased out the plaster looking for one..

New lintel in place and bricks back in, the acro came out once we finished with the sds drill. no movement at all - as expected.

The cheeks/jambs were - to my surprise, solid - I expected them to be a single course, so I needed 2 steel lintels on one side and one on the other, I know the calculation of the concrete one are fine (21nt with a 1050 length over 900 opening and I've put in 1110 over 800 opening), just need to prove the steel ones to the inspector.

I could have I expect, have gotten away without a building regs certificate, but I'm not good at lying and would have needed to when I come to sell it on.. £140 always well spent in advance i think.

Just the fireproof render and painting to go then hearth in.

 

[Landcruzer]

Hoodedclaw,
How did it end up?
I am doing a very similar job, but cant find the details of the W lintels you used.
Anyone know what the spec and name is?
I assume they are just there as extra support for the flue and flue bricks?

 

[hotrod]

I am doing a very similar job, but cant find the details of the W lintels you used.
Anyone know what the spec and name is?

They are single skin solid internal wall lintels. IG / keystone go them:-

http://www.keystone-lintels.co.uk/standard_lintels/index.cfm scroll down to the INT/K-100. Other companies may manufacturer a similar design.

hth.

 

[Landcruzer]

Thanks hotrod,
I spent an hour googling that and came up with nowt!
An idea how far the W type lintel should sit beyond the opening,
as it is basically holding up only the clay flue and any support around it?