Hearth or slate? What a concrete hearth does differently

Start with your stove, not the material. Its manual and the building rules set how big the hearth is and how thick. Only then do you pick what it is made of. Size comes first.

What do the rules say?

In England the rules sit in Approved Document J. A stove standing in the open needs a constructional hearth at least 840 x 840mm and 125mm thick. A stove tested to keep its hearth under 100°C can stand on one that is 12mm thick. That thinner hearth must reach 225mm in front of the stove and 150mm each side. Wales and Scotland have their own rules. Our post on hearth thickness for a log burner goes through both options.

How is a concrete hearth different?

I will not compare concrete with slate. I would only be guessing. What I can tell you is how ours is made. A concrete hearth is cast to your size in a mould, not cut down from a slab. If the rules and your stove give you 900 x 900mm, that is the size we cast.

The surface is sealed with a seal rated to 149°C. The 100°C test limit sits well inside that.

What should you check, whatever you choose?

Check two things, whatever you choose. If your stove's manual asks for more than the rules, the manual wins. Your installer signs the hearth off.

Where do you go from here?

Standard sizes, made-to-size hearths and the shop are all on our concrete hearths page. Free samples show the colour by your fire.