Fireplace

luckat

So I bring home a big tub of fire cement to fill in the side of the fireplace, where it's been a bit rocky and gappy for years. And the instructions on the tub say to clear away any loose, flaky or sandy material.

So I start clearing, and the next thing there's a waterfall of sand out the side of the fireplace; it just keeps coming.

Now I don't quite know what to do. Do I just clear it away until it stops coming, or is this sand an essential fireproofing and do I need to replace it somehow? Or should I just call a fireplace expert, and where do I find one?

northdublin

the sand that came pouring out is like kiln sand its to provide heat insulation between the fire brick which you were attempting to repair and the normal blocks from which the house is contructed.
it would be advisable to replace this as the heat of the fire could damage the block work of the house. i think its kiln sand they use and should be available from builders providers.

luckat

Thanks, northdublin. I was also talking to a builder friend who said it was probably to keep the old back boiler (now disused, but he suggests that it should be kept in good order) insulated.

He suggested using newspaper to form a barrier so the fire cement doesn't fall into the back of the fireplace. I don't really fancy this.

What can I use (a) as a barrier so the kiln sand (thanks) doesn't fall straight back out again, and (b) to form a backing for the fire cement?

northdublin

without seeing the damaged area its hard to say, if you have room and its not visable maybe some tinfoil or if you can get your hands on some sheet metal, also wetting the sand slightly might make it less prone to escaping and it should dry out the first time you light the fire.if posible when the sand is packed back in before you seal up with the fire cement brush on some pva glue mixed with water(polybond). this might seal the sand enough to get a start with the fire cement. im not a builder but i am rebuilding my own fireplace at the moment.

luckat

northdublin, thanks so much for this great advice. I'll go down to the plumbing supplies shop tomorrow and get some sheet metal cut to the right shape, and then come home and pour in some sand using a funnel.

It wasn't a huge amount of sand that came out - about the amount that would fill the tray under the firegrate.

Wetting it is a brilliant idea. Though I don't know if pouring it in the side is going to help the back boiler.... but anyway it's unlikely I'll reinstate that back boiler, I suppose; it was decommissioned when I moved to the (then cheap) gas central heating option 15 or 16 years ago.