Replacing firebricks in open fire?

nzoomed, May 1, 1:35am
We have just purchased a property which has had an open fire, but the last owers had installed a kent in its place and has since rusted out, so they removed the woodburner and blocked off the fireplace with a sheet of plywood.

Anyway, its still got the steel flue inside the chimney which i will probably remove, and im getting a chimney sweep in to give it a service and clean but i asked him about replacing the firebricks and he didnt think there was such a thing in such fireplaces.
Its a 60's home with a concerete chimney.
Do they typically line the fireplace with firebricks or are they typically left as is?
I dunno what is involved with installing a kent, but id rather enjoy the feel of an open fire as a feature rather than spending $$$ on a new woodburner since the in wall ones dont throw out that much more heat than an open fire anyway.

TIA.

skin1235, May 1, 1:46am
60's were not concrete for a start, they were pumice molded blocks, and no not all of them had brick lining in the firebox area, you can put bricks in, helps cut down the firebox size and therefore the amount of draft, won't make any difference to the 80% of the heat going straight up the chimney ( which is $8 out of every $10 you pay for the wood )

not sure where you get the idea that an inbuilt log burner emits less heat than a freestanding one - the figures don't add up, if you fit a 12kw burner it will emit 12 kw, if its inbuilt or freestanding ( inbuilts do not have an open chimney, it is sealed against the flue at the top - they're actually cheaper to instal; cos they don't need the triple shielding of an open flue)

skin1235, May 1, 1:51am
a man of your ability nz', would have an 80mm 12v fan quietly pushing cool air under the firebox and up around the sides to exit into the room, in about as long as it took you to pull one out of an old tower and find a tranny for it, then back off to the other side of the room and start opening windows cos its too hot

( thermal convection is the issue with most inbuilts, they are too restricted by the hole size and shape and the fire itself just keep getting hotter and hotter) a little bit of forced air does wonders

edit, the pumice blocks were light to use, but also softer too, and if it hasn't had bricks in it it could be by now becoming quite scarred, bricks will renew the exposed surfaces and give you a sacrificial surface to work with ( 40 yrs plus = sacrificial )

skin1235, May 1, 2:04am
third and last : put a lining of bricks in it, make the base quite wide and deep ( two bricks up at least ) buy the grate you want

then get 4 lengths of heavy wall 50mm pipe and have them bent so they start about 100mm out from the upper edge of the mantle, bend and go down through the flame area to the back of the fire, then bent so they follow the back of the fire to the grate, behind the grate, ( pass through or set the grate forward suffice) and then bend and come out to the front of the edge of the firebox
they can be chromed or heat enamel paint, but be aware they get very hot, the edge of the mantle may need shielding or bring the pipes further out away from it. they get so hot I used to light my cigs by holding them over the air flow coming out of them, felt like 3 times as much heat in the room in a much shorter time

nzoomed, May 1, 3:27am
Yes interesting what you say about pipes and fans etc ive had a friend who got some steel pipe like you said and puy it together in a loop configuration with a computer fan feeding in cold air and then blowing out the hit air leaving the heated pipe seemed to work well.

pisces47, May 1, 3:35pm
have a small fault in the bricks at the back of our fireplace. Chimney serviceman quoted $750 to replace a couple of bricks. This was several years ago. Would this price be reasonable

nzoomed, May 1, 5:04pm
$750 seems like a joke, unless its something more involved in the chimney itself.
I dunno much about what is involved with replacing them, i dont know if its mortar or or some other cement that holds them together or if they are put in loose.

I can find a local supplier of bricks for kilns that are only $1 each anyway, im going to buy some.

pisces47, May 1, 11:25pm
Had a look at area and there seems to be 2 or 3 bricks that need re mortoring ? You can buy this at handyman store and bricks are relatively cheap. Any one you can recommend to do the job at a good price ?

skin1235, May 2, 1:25am
the pipes don't need a fan, they enter from beneath the grate, go up through the fire zone and exit at mantle height, convection takes care of air movement - don't skimp at the exit end, theres a lot of heat coming out that air stream, keep it well away from wood or wall surfaces etc ( imagine a somewhat squared question mark - upside down, 4 alongside each other about 100mm between each, even splay the exits, a couple of steel straps to holding them in the required position, freestanding in your fireplace, then put the grate back in

the fan thing was if you decide to put another box in the hole, most do not have fans and rely on convection to move the air up and across the firebox radiant surfaces, in a squared insert easy flow is thwarted, put a PC case fan under the firebox so you can force induct air to shift it round better

skin1235, May 2, 1:29am
I'd check re mortar, suspect plain cement and sand may not handle the heat for too long before splitting or cracking, maybe, maybe you need a more pumice mix

nzoomed, May 2, 2:11am
OK, ill take that on board.
I may do this as a temporary measure, but im thinking of installing one of these at a later point.
They tell me they are pretty efficient compared to a regular open fire.
http://www.warmington.co.nz/wawcs0142192/idDetails=165/RETRO%20Fitting%20Open%20Fires%20Wood

pisces47, May 2, 2:24am
Re; my remortoring, there is a proper fireplace mortar available. Available at mitre 10 etc.

skin1235, May 2, 2:42am
yep, I'd imagine it is pumice and cement rather than sand and cement, or a high pumice content

nzoomed, May 4, 5:07pm
Anyway, have been reading about the rumford fireplace, apparently these things were amazing, so why did they fall out of favour?
They were a revolution when invented at the time, yet more modern homes did away with them!
Im keen to find someone who could redesign ours into a rumford design.

rusty-bones, May 4, 5:13pm
I thought fire places will no longer be able to be used? You may just want to check up on this in your area first before spending money. It may not be for a couple of years yet though.

nzoomed, May 4, 6:19pm
Only Christchurch and Rotorua are banned that im aware of, possibly other areas too, but no restriction in Tauranga.

golfaholic2, May 6, 3:58am
I skipped that section in the newly proposed Chch air plan , assuming it hasn't changed , an open fire can be used from Oct1-March31 .

peter148, May 6, 4:13am
I've got an old Masport wood burner which has a fan blowing air from underneath the firebox around the outside and out the top, which is brilliant.
I took the fire bricks out, which were all degraded and broken down. Now i have more room in the fire box itself but the downside is that the fire is not as intensely hot inside the firebox. so that the fires take a bit longer to heat up.

nzoomed, Jul 8, 9:33pm
Just an update guys, i managed to find a person to reinstall the fireback thanks to a supplier of the bricks on Trademe!
He makes the bricks himself and they only cost us $2 each (the same price listed on TM)!
Whole job only cost $750 including the bricks.

Anyway, im happy enough with the heat it puts out, like any fireplace, its pretty much only radiant heat, no hot air, just the heat from the fire itself, but when its stoked up you cant stay any closer than a meter away for long.

Ive got the deepest grate i can find, but there is still a 60mm gap between the back of the fireplace and the back of grate so i may have to extend it with another piece from an old grate, but if i install some steel pipes, they will help take up some of that space too.

Photo is here.
https://trademe.tmcdn.co.nz/photoserver/full/395584650.jpg

nukhelenc, Jul 8, 11:04pm
Strongman coal and blue gum, i had the grate stuffed in 6 months, boy the heat :)

nzoomed, Nov 27, 5:12am
I heard the grates dont like coal but im going to try it. Not sure how coal ranges handle it but cast iro is supposed to be better than steel