I am currently make some major changes to the house.

I have removed the chimney breast and want to install my stove as freestanding with a twin wall flue.

From reading the stove spec and building regs, I will need/want a 900 x 900mm hearth. Can this be installed as single piece or do I need to make it from 2 or four sections to allow some expansion and avoid cracking?

Also, I have looked at a couple of flue design websites and they seem to offer a good service but I am wondering if they charge a significant premium over speccing individual components from a local supplier?

Can anyone recommend any of the on-line flue suppliers?

It sounds as if you are looking to DIY. If so, what are you doing about getting the installation signed off for building regs?

I will be using the building control officer to sign off.

It will be installed as part of the building works, the builders are happy to do so and have had several installs signed off without using HETAS installers.

The HETAS guys seemed to want a day rate of about £500 per man per day, which is just silly.

Decent stoves will not push much heat downwards – the marble/granite/whatever below our 8Kw Clearview gets warm but nothing more so cracking is not an issue.

I’ve got slate under mine, tiles as it happens but the supplier said whole would be fine too

Some stoves are suitable for 12mm hearths such as glass, others are not. If it is then the hearth will never get hot enough to crack. Check the spec of your stove to find out. If it is not then it will be material dependent as to whether or not you section the hearth (from a risk perspective)- slate for example is more likely to need sections.

we have a metre square slab of slate. Barely even gets warm.
I once tried to dry my shoes out in front of the stove and they were still sopping wet at the end of the evening.

All the heat goes up. Stand on a chair when the stove is burning and you’ll feel how much heat collects at the roof.

As many pieces as you want will be fine, laid on a decent base.

My wife wanted a slab of slate, and while we could get it (although needed a special order for the size) the local supplier suggested we’d be better off with other stone as the slate marks easily.

We ended up with a sheet of black marble, which I ‘buffed’ to a non-gloss finish at the stone guy’s place. Took 3 of us getting hernia’s to shift it… (1200mm * 900mm).

I’ve done dozens in one piece, only had one crack though. It was Chinese slate, the quality was sometimes a bit iffy so it may have had a fault in it already.

If you’re anywhere near Sheffield, I have a square of slate (we ended up buying 2 identical pieces) available. email if you want measurements..

Why twin wall flue?
From the stove to where it goes through the ceiling or roof could be std flue pipe then steps upto twin wall?

Well that’s what mine is like. Also freestanding on a glass 12mm hearth.

From the stove to where it goes through the ceiling or roof could be std flue pipe then steps upto twin wall?

Yes it will be. A length of stove pipe up to near the ceiling.

500 a day… i need to put my rates up!

Totalshell – where are you? I am in Kent.

If you are HETAS and willing to charge a reasonable rate to install a flue you can have the job!