Making a chimney breast deeper

Hi all,

A rare one this - I can find loads of people wanting to get rid of chimney breasts, but I need to make mine bigger!

I'm fitting a wood burner and would like to make the chimney breast deeper so that (a) I can install fitted cupboards either side, and (b) the hearth doesn't stick out comically and people keep tripping over it.

The existing chimney's only 37cm deep, the hearth is going to end up around 68cm deep. Ideally I'd like to add around 10cm to the chimney depth.

If it weren't for the fact that there's a wood burner going in, of course I'd stud it and plasterboard. But with the burner in, what other options do I have? Is it simplest build a block skin using breezeblocks, somehow keyed into the existing chimney?

Many thanks,

Russ

If using concrete blocks, why key them in and risk damaging the flue? Try s/s angle brackets screwed to the wall, perhaps every other course.
Is there a structural hearth for supporting the blockwork?

Just a little note, if you are fitting the stove yourself, your Building Control Officer will need to be notified or it will need to be installed (or possibly approved) by a HETAS registered engineer (building regulations/insurance). Unfortunately that adds to the cost.

Another point to consider is that making a chimney breast may look nicer but it can also reduce the air flow of heat that goes into the room

russella said:

Hi all,

A rare one this - I can find loads of people wanting to get rid of chimney breasts, but I need to make mine bigger!

I'm fitting a wood burner and would like to make the chimney breast deeper so that (a) I can install fitted cupboards either side, and (b) the hearth doesn't stick out comically and people keep tripping over it.

The existing chimney's only 37cm deep, the hearth is going to end up around 68cm deep. Ideally I'd like to add around 10cm to the chimney depth.

If it weren't for the fact that there's a wood burner going in, of course I'd stud it and plasterboard. But with the burner in, what other options do I have? Is it simplest build a block skin using breezeblocks, somehow keyed into the existing chimney?

Many thanks,

Russ

Click to expand...

Any chance of a/some pics to make sure we are all understanding what you are saying? There are a number of options but just want to make sure I have understood you............

This isn't actually my chimney, but it's pretty much identical brickwork - an arch lintel, a double-width layer of bricks at each side.



On the subject of keying in, I was considering using screw-in ties like these? As long as my breeze-block courses don't line up with my brick courses this should do the job?

Thanks,

Russ

Metal studwork and plasterboard is fine.
Though not as pretty as custom built brick or stone.

I like the metal studwork idea - so the idea is I could attach these metal studs to the face of the existing brickwork, and then board over the studs? Are these the kind of things I'm after?

However I'm still concerned about using plasterboard directly above the wood burner, for example the underside along the top of the chimney opening. For small areas directly exposed to heat like this, are there any alternatives to plasterboard?

Thanks,

Russ

Plasterboard could crack since it is not heat resistant. Lime mortar was used in the old days to parge chimney flues. You could try and use lime plaster on the underside along the top of the chimney opening.

Again thanks all for your help, I've got a builder doing the lintel work for me on the existing chimney, then it'll be full steam ahead for myself!

Russ

Hi all,

An update - the deed is done! (pretty much).

In the end I decided to do the job in two sections - the chimney opening I've extended "properly" by using bricks from a neighbour's demolition project, removing alternate bricks up each side of the fireplace (with props to support above the fireplace of course), then keying in new brickwork to bring it forward a half brick . Very laborious for someone like myself who's not done more than a day's bricking in my life, but very satisfying now that it's done.

The main reason I've done the fikreplace properly is because I want to ideally have the interior of it painted white, and not plastered or rendered or anything similar. Of course if I'd used breeze blocks, this wouldn't have been possible.

As for the part of the chimney above the fireplace, I'm fitting a second lintel in front of the existing one, and I'm going to be using breeze blocks keyed into the existing bricks using a wall extension / starter kit (something like this). I figure the front and sides of the chimney will be plastered, so this quick-and-dirty approach will be invisible. And if anyone ever wants to do it properly in future, there's minimal damage to the existing brickwork.[/url]

So thank you very much for the help so far, and I'll try to get some pictures up once all the structural work is done, then again once it's plastered.

Russ