Blocking up builders opening left by fireplace

[JamesAsus]

So i need to breezeblock up inside where an old gas fire was in my house, the gas fire basically went all the way back to the single skin wall so a section of breezeblock was cut out to fit the whole fire at the time.

Im now left with an opening that only has a single skin brick to outside, size is about 80cm by 1 metre high, there is a lintel above the opening obviously put it at the time the fire was.

The gasman said they dont do brickwork to that extent as it would need tying in to the exising breezeblock.

With the opening having a lintel above it, would it really need tying in to what is already there? To be truthfully honest what is already there is a mess anyway its hardly straight or even.

Im tempted to do it myself thats all but if its a job for the pros fair enough, he said something about putting damp proof membrane behind it aswell. Ive attatched a picture to the thread.

THERE IS NO CHIMNEY BREAST THIS FIRE WAS VENTED DIRECTLY OUTSIDE INTO OUR SIDE ALLEYWAY

Cheers

 

[footprints]

Well it is supported if it has a lintel, I would be tempted to just brick up the hole matching the bricks on the outside as well as possible then put a timber frame in and a sheet of plasterboard on the inside with some insulation between. look carefully at the join between the existing brick and blockwork to see if there was any kind of vapour barrier in the original construction. I guess the black is just that so yes replace with something similar.

 

[JamesAsus]

Well it is supported if it has a lintel, I would be tempted to just brick up the hole matching the bricks on the outside as well as possible then put a timber frame in and a sheet of plasterboard on the inside with some insulation between. look carefully at the join between the existing brick and blockwork to see if there was any kind of vapour barrier in the original construction. I guess the black is just that so yes replace with something similar.

There is a vapour barrier yes, its that black stuff.

So could i just cover the brick with that vapour barrier and then put loads of foam insulation in and then stud frame and insulated plasterboard?

Does that barrier just stick onto the brick?

 

[JohnD]

it would probably benefit from some kind of insulation in the cavity. If it is ventilated to the flue it should not suffer from damp.

or is the hole for an old type of balanced flue, with no chimney above?

 

[JamesAsus]

it would probably benefit from some kind of insulation in the cavity. If it is ventilated to the flue it should not suffer from damp.

or is the hole for an old type of balanced flue, with no chimney above?

There is no chimney sorry forgot to say it vented directly outside into our side alley (via a vent of course)

 

[footprints]

I would avoid foam , messy stuff. Get something like Rockwool or nicer to work with the recycled plastic bottle stuff which is non itch. Celotex would be easy to use too. Ordinary plasterboard will be fine inside. Some vapour barrier sealed to the existing with a sealant or maybe flashing tape should suffice. I guess at a push a bit of roofing felt would do.

 

[JamesAsus]

Brill ill go with that option then, trying to keep costs low, so adhesive DPM to the brick, then fill the cavity with rockwool/celotex etc then stud to the breezeblock, attatch plasterboard to the studs then skim coat?

When you refer to celotex do you mean stick that to the brick (on top of the dpm) as it comes in boards, or fix that via studs and then plasterboard on top leaving a gap between celotex board and external brick?

 

[footprints]

Just cut the sheets to be a push fit in the hole, as you need to buy a full sheet a thinner one cut into several sandwiched sheets will be more economic than getting the really thick stuff with loads left over.

 

[JamesAsus]

Just cut the sheets to be a push fit in the hole, as you need to buy a full sheet a thinner one cut into several sandwiched sheets will be more economic than getting the really thick stuff with loads left over.

Sorry you have lost me a bit haha, what do you mean? Sorry im not in the trade thats all.

 

[footprints]

Celotex is a stiff board of foam reinforced with glass fibre coated on both sides with foil, comes in 25 mm to 100mm thickness claimed to be equal to twice it's thickness in normal glass fibre / Rockwool insulation. Comes in sheets 2.4m x 1.2m. Nice to use but pricey.
https://insulation4less.co.uk/colle...YutdgrkxZA1LsG5-L-UCAQ2cHRHSTMpQaAjZ9EALw_wcB

 

[footprints]

PS this is cheap and easy to work with fine for what you need I would say.https://www.diy.com

 

[footprints]

Link not working Diall insulation £16 at B&Q

 

[JamesAsus]

Do i need to skim plasterboard these days? Or can i just tape and joint the seams? Seem to get mixed info online, my house is 26 year old and i 'think' it hasent been skimmed as i can slightly make out faint bulges where joints have been taped, very subtle but its there, and the finish otherwise is absolutely smooth as anything so seems a bit too good to be skimmed?

 

[footprints]

Depends how neatly you can inset the plasterboard.

 

[JamesAsus]

Do you think ill be okay damp wise by just fixing some DPM to the single skin wall and then filling with rockwool?

Its down a side alley and next doors side alley is next to it, so doesent really get any direct rainfall, and obviously its not a chimney.