Chimney - Internal Help

[richo106]

Hi All

 

We will be installing a log burner at some point (few years down the line at least) but have got a chimney built in preparation etc..

 

Please see attached photos of it currently

 

As this will not be used for a while what is the best way to 'Seal' just above the visible chimney line in regards to heat insulation and air tightness

 

Also what is best way to finish inside the recess in regards to plasterboard/plastering... is special board required etc.. I amp planning to use air tight paint to seal the block work (have a bit left over)

 

Basically any information that will be useful when completing this section would be very much appreciated

 

Many Thanks

[JohnMo]

Not sure a chimney is a wise choice. Ideally with modern well insulated and assuming a reasonable airtightness, the chimney goes against all that.  Your log burner, stove, really needs to take primary and secondary air from outside the building, so an air duct will be required, otherwise your are adding air bricks etc.

 

I would assume whatever you have done may not be suitable for a stove, I think you really need to talk with stove installer now rather than later, making changes now is easy, later you are pulling your finished house apart.

[ProDave]

I am not seeing a "chimney" there (do I need to look harder?)

 

I see the chimney breast formed but I don't see a masonry chimney coming out of the top and up through the roof structure?

[richo106]

7 minutes ago, JohnMo said:

Not sure a chimney is a wise choice. Ideally with modern well insulated and assuming a reasonable airtightness, the chimney goes against all that.  Your log burner, stove, really needs to take primary and secondary air from outside the building, so an air duct will be required, otherwise your are adding air bricks etc.

 

I would assume whatever you have done may not be suitable for a stove, I think you really need to talk with stove installer now rather than later, making changes now is easy, later you are pulling your finished house apart.

Yes agree with comment regarding that chimney's are not ideal but we wanted to keep a balance between modern and traditional. It will be taking air from external when installed (through the back)

 

I have attached a picture of the back of the house, there is no liner currently installed just a space for it to go. As you can tell I have never done anything like this before, the air tightness concept was something i decided on after the build had started so trying to make it the best it can be for my build.

 

 

 

 

[JohnMo]

I would talk with a stove installer, get the correct liner installed now and blanked off. Then discuss how to insulate, you may need to fill with vermiculite or similar. Not sure how you get access?

[saveasteading]

31 minutes ago, JohnMo said:

making changes now is easy

The air supply pipe is fiddly even when done as part of the job. it would be very disruptive as a later addition, unless pipes are left on show.

Its got to be a good thing though. 

[JohnMo]

2 minutes ago, saveasteading said:

would be very disruptive as a later addition

Especially if you are core drilling through block work, when the room is finished and furnished.

 

I say do it all now or don't bother at all. If you don't do it now fully insulate the chimney and seal off. Get a fire backet and some logs and make a feature of it, knowing you will never use it. But if you really wanted too you could, with some mess.

[richo106]

I honestly think we won't ever bother doing it but i just wanted to be a little prepared if we were to, can i just use normal plasterboard and plaster or do i need to use cement board and plaster?

 

Regarding the insulation, i have attached a couple of pictures

 

One is a cavity in my chimney, its 100mm cavity with 90mm thermclass

 

The other picture is my original idea in regards to insulating it 'temporarily' I was going to stick a bit 150mm PIR in and Air tight tape the edges to the block

[crispy_wafer]

Looks alright does that!, A decent stovefitter will know what to do with regards a liner if you want a stove.  You can core in an air feed for direct connection to the stove.  Just requires a bit of careful selection on stove with regards room sealing, primary/secondary feeds. 

 

What you thinking of, inset, or floor standing?  Putting an inset into mine just for the cleaner lines, more than anything, but that's a personal preference.

[richo106]

Thinking of a floor standing one, but a tall one to suit the opening.

 

Am I ok to dot and dab normal plasterboard on the inside of the breast and then skim? 
 

I am guessing I am not so any advice on this would be great

 

Many Thanks

 

[Temp]

What's inside the main chimney? We have one that's "offset" but ours is to the side rather than the back.

 

Inside our chimney we used 210mm (?) ID pumice liner blocks/tubes. Theses were built with the chimney, as you would the inner leaf of a brick and block wall. At the bottom there is one with a 45 degree bend to bring it out through the wall into the fireplace. To the bottom of that I fitted a register plate (more like a register funnel) to reduce down to the 150mm stove pipe. 

 

Get this sorted ASAP because I have a feeling stainless liner type flues aren't allowed on new builds only for lining old chimneys. I might be wrong though.

[Temp]

I forgot....

 

We wet plastered the fireplace. I got a local stone Mason to supply some 20mm black granite for the stove to stand on. He cut this to my template. This must be the right shape and size to meet the regs. It must be 12mm higher that the finished floor for the rest of the room. The stove must be certified not to raise the temperature of the hearth more than 100c.

 

I can recommend the Clearview stoves but they might not have one tall enough?

 

[crispy_wafer]

2 hours ago, richo106 said:

Thinking of a floor standing one, but a tall one to suit the opening.

 

Am I ok to dot and dab normal plasterboard on the inside of the breast and then skim? 
 

I am guessing I am not so any advice on this would be great

 

Many Thanks

 

Not sure about plasterboard, I guess it depends a lot on the stove and distances and how much heat it will need to absorb, failing that then render/plaster it.  If you can I'd call your BC and ask what he'd expect to see, mines pretty good at answering my sometimes daft questions. 

 

VITCAS do some high temp stuff but might be belt and braces.

 

HWAM have some nice tall'ish stoves I reckon might give a nice balance of modern and traditional... 

 

A bit of stovepipe, a flexi, coupling, register plate, and chimney hat... Is what I think an installer will probably want to use I think.  Even on mine where we've got clay (or something or other) liners installed. 

 

[twice round the block]

The building regulations have changed regarding log burners. 

You really need to get a stove / chimney expert in there now for some advice before you go any further.