Prep for tiling hearth - log burner

[Ian Tinkler]

Morning,

I'm building a hearth for a log burner. Plan is to use bricks to build it up from the concrete subfloor. I need to level before tiling. Can I shutter it and pour a thin (say 5mm) layer of self levelling screed to give me a flat surface to tile from?

My concern is heating might cause cracking / expansion.

Is a concrete (hardibacker) board better? If so how would you attached to the brick hearth below?

This is only for the base - the sides I'm using concrete backer boards as obviously a screed is not an option.

Second question - is there an issue with small air gaps being left between the tile and adhesive layer expanding? It's not exposed to direct heat but I imagine it'll get quite hot.

Thanks in advance!

 

[Lower]

You know you can buy pre-cast tiled heaths to whatever size you want?

https://www.castfireplaces.co.uk/hearths-and-chambers/tiled

Save you a load of time and hassle.

 

[Ian Tinkler]

Thanks - didn't know that, bought the tiles now and it's not a rectangular space, but definitely would consider another time.

 

[Lower]

They make them to order. I've bought a couple of T shaped ones and they're very good.

 

[StephenStephen]

I'm not a professional, but if any one of my woodburners was sending enough heat down through the legs, then through tiles, to crack a screed underneath I'd be worried about the woodburner!
I found this site useful: https://www.stovefitterswarehouse.co.uk/pages/hearth-regulations

 

[JaimieH]

I wouldn't bother buying a self levelling compound in addition to adhesive. Shutter up the sides as you are planning to do and spread a layer of C1 or C2 adhesive (rapid, or standard set, whichever you prefer) and trowel flat. Once set use same adhesive to lay tiles. It is important to avoid any voids under the tiles, not least because of the weight of the log burner, and you want to achieve as close as possible to 100% coverage. Trowel size is important and will depend what size tiles you are using but for anything 300mm and above I'd suggest a 20mm u-notch trowel or 12mm square notch and back skim your tiles before you bed them.

 

[foxhole]

IMG_2500

• foxhole
• 1 Dec 2018

Very little heat reaches the floor. its main role is catching any hot debris that might fall out when feeding the fire.Used york stone [reclaimed from church ] For mine.

 

[JaimieH]

Boodiful