Glass bricks in chimney?

[meaning]

Howdy all

We have a chimney in our existing kitchen that once housed a wood-burning stove (long gone, unfortunately). The opening to the room is 930 wide by 1330 high with double bricks either side and single outside, and has a window 220 x 330 high, that we'd like to replace with as many glass bricks as is practical (we want to get as much light as possible from the North wall). The thing is, it's going to be dining/living space and it'd be nice to put our wood heater there, SO

1 - does anyone know if glass bricks will stand the heat?

2 - if so, how many we could get away with using before compromising the stability of the chimney too much?

3 - best grout/mortar/other to be using?

cheers,
mean..

[seriph1]

sorry - not quite following...... you want to replace the window with glass bricks or the chimney?

mortar: I feel the suppliers of the blocks will be able to advise best .... I have seen silicon and cement, as well as a plastic strip.

[Markw]

Glass bricks will not take heat, nor will the cement used between them.

Anyway, once a fire is started adjacent to them, wouldn't they be covered in soot? :confused:

[meaning]

Well, it's an enclosed wood heater, so the flue would be going up the chimney, in front of the window.

It's the window we want to replace with glass bricks, but also enlarged as much as possible.

I'll be able to get to a glass brick place on Saturday, just wondered if anyone has tried anything similar...

cheers
Meaning

[ozwinner]

The cement, mortar used to stickem all together, or is that apart?

Will take the heat of the fire no probs, but the glass wont.

Al, the retired brickie.

[wombat47]

I've seen a couple of old kitchens with windows in the fireplace - lets the light into the cooking area, in the daytime at least. They were in use with old wood burning stoves, not the insulated slow combustion types, and the glass in them must have coped with a lot of heat in their time.

I think your use of glass bricks is going to depend on the type of wood burning heater you are going to install. If you are thinking of a cast iron heater, then you will have to contend with a fair amount of heat transfer within the chimney area. This may not be good for the glass bricks, or the mortar.

If you go for an insulated box type heater which puts most of the heat out the front, your should be able to get away with the glass bricks. You would need to install a double flue, and don't forget to seal off the chimney to keep the heat in the room and the wildlife out.

It might be an idea to contact a glass brick manufacturer for advice. As for compromising your chimney, I think that the backs of most chimneys are only single thickness so you might need advice from a brickie here.

[meaning]

Thanks all for your comments.

Just thought I'd post what I learned from the glass block place today:

They do actually make fire-retardant glass blocks for use adjacent to fires. Frame-wise they require gal as opposed to the standard aluminium, and of course mortar rather than silicon.

In our situation where it's only the flue going past the blocks, they reckon standard blocks with aluminium frame should be fine. We just need to put a lintel above the window as the blocks aren't load-bearing.

cheers, I'll post a photo when we're done!

Meaning

[Robert WA]

Well, it's an enclosed wood heater, so the flue would be going up the chimney, in front of the window.

It's the window we want to replace with glass bricks, but also enlarged as much as possible.

I'll be able to get to a glass brick place on Saturday, just wondered if anyone has tried anything similar...

cheers
Meaning

Meaning.

Not quite on the topic.
If you can arrange for the flu to be within the room you will get more benefit from the heater. The hot flu within the room, rather than in the chimney, will give you more heat.

[Marc]

Flues from wood heaters get realy hot if they are single skin, for that reason you must have a shield between the flue and the wall, inthis case your glass bricks. Sheilds are double skinned and there are specific minimum distances for the wood heater to be away from walls.
Modern slow combustion woold heaters have shields behind the body of the heater as well. The heat transfered with a shield in place is negligible, or all the walls behind wood heaters would be burned black or peeling the paint off, and insurance companies very busy.