back of fireplace, plate broken

yeahme

Hi today cleaning out the open fireplace the (run of the mill variety)
I noticed the 8 in long by maybe 5 in wide ceramic? plate was loose, and the caulk or cement used to fill it was cracked,
now more pulling and dragging by me, resulted in the plate coming loose altogether.
When i pulled free, a substance fell free from behind the chimney spilling out from where i pulled the plate,

Can any one tell me what this substance is used for, they look like small pebbles, but are soft, and ligher and dont burn, as i tried to light them. are they important, and will i need to replace the lost ?pebbles?

I guess they are to do with fire insulation against wall, but my knowledge of fireplaces is limited to just starting a fire, and i dont want to create a fire hazard
more importantly,
can any one recommend what to do with the plate, cos now the house is kinda cold,
can i seal it back into place with the leftovers of some "high temp rtv silicone" gasket maker, from an old project car, or
will i use soome other type of sealant,

Thanks in advance
Yeahme

yeahme

I have done a bit more looking up and its a kind of sand/pebbledash mixture,
but if anyone has any more experience can they let me know how to fix,

its freezing here, but i dont want to put the fire on in case of fire hazard

RKQ

I'm not sure what you are referring too.
Is the plate you refer to a cast iron fireback?
This sandy small pebbles could be fireback backfill. A few photos would really help explain your query.

Fire cement comes premixed in tubs at any local hardware and is usefull for fitting or repairing concrete firebacks. I wouldn't be too sure about using high temp rtv silicon.

yeahme

Hi RKQ,

ive tried senting photos from my phone earlier, but they are not sending,
so i have tried to explain as well as i can,,

its a back plate (cement or ceramic) set into the very back of the fireplace its about 8/9in long and about 5/6 in in height, its set at the bottom of the fireplace grille to just below the exit for the chimney,

when i took photos i took the plate off and more of this substance came out, tbh it feels more like shredded styrofoam than sand/pebbledash:eek:


yeah i might leave the silicone for the car engine so

AckwelFoley

yeahme wrote: »

Hi RKQ,

ive tried senting photos from my phone earlier, but they are not sending,
so i have tried to explain as well as i can,,

its a back plate (cement or ceramic) set into the very back of the fireplace its about 8/9in long and about 5/6 in in height, its set at the bottom of the fireplace grille to just below the exit for the chimney,

when i took photos i took the plate off and more of this substance came out, tbh it feels more like shredded styrofoam than sand/pebbledash:eek:


yeah i might leave the silicone for the car engine so

Ive never seen a ceramic fireback, any ive ever seen are concrete.

Is it like this?




The fill comming out of the back if its not a sandy type substance it could me micafill, but this is only used in the last few years, so unless its a new house or one that has had work done its not this either

yeahme

sorry synper,
i should have mentioned house is about 8 years old, so its newish

errr the pic is not like that at all, but material (cement) would be similar, but made into the form of a lookalike grate, feckin phone pics wont sent another problem:rolleyes:

now the fire cement filler used on the sides of this plate was all cracked and loose, so it just took a minimum of force fro me to dislodge it from the back of the fireplace,

so maybe just fill her up again with cement filler and start a fire?,
but then what about that loss of mica, Styrofoam, sand/pebble-dash stuff,?
a good few handful's escaped
can that cause a fire hazard?

AckwelFoley

yeahme wrote: »

sorry synper,
i should have mentioned house is about 8 years old, so its newish

errr the pic is not like that at all, but material (cement) would be similar, but made into the form of a lookalike grate, feckin phone pics wont sent another problem:rolleyes:

now the fire cement filler used on the sides of this plate was all cracked and loose, so it just took a minimum of force fro me to dislodge it from the back of the fireplace,

so maybe just fill her up again with cement filler and start a fire?,
but then what about that loss of mica, Styrofoam, sand/pebble-dash stuff,?
a good few handful's escaped
can that cause a fire hazard?

The purpose of the fill is for moreso around the chimney flues and the chimney wall, i dont know why the fireback cracked, they shouldnt. Chimneys need the fill t support the chimney flues, but you cant use cement as cement is fully rigid - if there is a chimney fire and the flues crack, through expansion the fill absorbes the cracked flue and doesnt allow the expansion to crack the chimney stack. If the mixture between the flue and chimney wall is incorrect it doesnt stay rigid and when the chimney crack.. sand comes down the chimney into the fireplace, and eventually you may have soot damage seeping through your blockwork.A proper fill should act like sticking your finger into bread, it will allow the movement, but there is no collpase like if you stuck your finger into a bucket of sand

I cant see exactly the problem due to not having any pictures (sorry - i know phones can be a pain in the arse) so id be ill advised to say there is no fire hazard. however as there is no combustable materials behind a fireback i wouldnt think there is a particular risk.

The only proper solution to this problem is to have the fireback replaced and refitted.

yeahme

Ok i have the pics now I hope they just upload :fingerscrossed

then ye might be able to recommend something to do..


wahoo, they uploaded "got to love the 02 helpdesk, quick on the ball"

demanufactured

Thats a wierd looking fireback.....

RKQ

Picture tells a thousand words....
It won't be possible to put back the "back fill" without removing the cement throat at the top of the fireback, where it meets thye flue.

All firebacks have non-combustible material behind them, ie betweem the fireback & the chimney wall. This material can be bits of old plaster, mortar droppings etc. It accommodates the expansion and contraction of the fireback, fills the void preventing a fire in the void.

Use fire cement to fix the "plate" back in place.
http://www.c20fires.co.uk/fireplace_fitting.htm

yeahme

thanks rkq, i am already on myy way......

AckwelFoley

Yea, as per what RKQ said.

yeahme

thanks rkq snyper,
back to a warm fire,
nothing like a bit of turf smokeing away

Dammo

Hi guys,

This is the nearest I've seen to an answer to my question without starting a whole new thread, so I'll chance you guys first.

If the fireback is cracked, can it be filled with fire cement, or does it need to be replaced altogether?

There's a crack straight across the back and one down the 'crease' at the side. The lower end looks like a badly pock-marked face as well (sorry about the image!).

Any help would be greatly appreciated.

Thanks.