Rendering a fireplace

[stuartpaul]

I know this technically isn't woodwork (alright, - it isn't woodwork at all!) but it will be when I fit the new mantle etc.

SHMBO wants a log burner and I'm in the process of removing the old fireplace and beating out firebricks etc.

The resulting opening will need to be rendered to provide a suitable finish and I'm pretty sure that a lime based mix will be more appropriate that a cement one. The movement required from quite a hot burner will almost certainly crack cement I'd think.

I'm looking to use one part masonry mortar (already has lime added) with two each of fine and coarse sand.

Scratch coat about 12mm then a final coat on top (about 5mm).

Is this the best way or are there alternatives?

Thanks

Stuart

 

[barkwindjammer]

http://www.wickes.co.uk/Ready-Mixed-Fir ... nvt/154057

 

[hanser]

some useful stuff here http://www.diynot.com/forums/viewtopic.php?t=142247

I built a fireplace with a rendered finish above the mantle and I used a lime based mix - lime, sand and a little white cement for 'whiteness'

Its been on 15 years and no cracking. The lime makes the mix 'fatty' and easy to push around and flatten off. Best tool is a polyurethane type float. The lime also gives it a long 'wet' life. Getting dust off the old surface and using PVA is probably good advice.

 

[wobblycogs]

That roughcaster guy on diynot has given me some really good advice over the last couple of years. Cement will crack if used as a render (as happened with ours) but once it's finished cracking after a couple of good hot fires another coat of paint will cover the hair line cracking and you wouldn't know the difference. Any water based paint is suitable, oil based aren't.