Pouring Concrete Hearth For Wood Burner

[ikearns]

Hi All
We are looking at putting a wood burner in one of our reception rooms and rather than a polished hearth we are looking for something more 'rustic'.

I was thinking of pouring a concrete hearth on top of some cement board and shuttering it to make a form.

has anyone else done this and do you know of any dimensions that you have to abide by?

Cheers

 

[Ian H]

I just made one out of a 3x2 stone slab, that's pretty rustic for £12.

 

[Doggit]

Check on the dimensions required by the stove first. But I wouldn't put cement board down unless you've got a nice flat surface underneath it. You should throw in some rubble and compact it down, put some sand down to blind it, and then put in a dpc that laps up the sides, and then pour in the concrete. And then float it as flat as possible so that the stove sits flat rather than wobbles.

 

[ikearns]

Thanks for the first replies.

I have used large 18" tiles in a previous hearth but as this one may be more functional (the other has a gas fire on it) then I was looking for something more substantial.

If you need to extend the depth of the hearth over the current floorboards then I was thinking that the cement board would give a base area that can be cut to size and even notched so you can get it all the way into the fireplace opening

 

[Doggit]

If you've got to extend the hearth further out, then you're better off cutting out the floorboards, and making sure the hearth goes down to solid ground. You can guarantee that you'll either rest the stove on the edge of the hearth, and it'll crack, or someone will stand on it one day and do the same.

 

[ikearns]

If you've got to extend the hearth further out, then you're better off cutting out the floorboards, and making sure the hearth goes down to solid ground. You can guarantee that you'll either rest the stove on the edge of the hearth, and it'll crack, or someone will stand on it one day and do the same.

That would be some considerable work considering that there is a cold space void underneath the floor. The house was built in 1902.

 

[Doggit]

Then I'll leave you to work out the best way to handle it.

 

[lostinthelight]

http://www.stovesonline.co.uk/stove-hearth-size.html
litl

 

[geraldthehamster]

See Approved Document J (2.22 onwards) for the Building Regulations requirements for hearth. 2.25 in particular is relevant to your plan for the hearth to extend over combustible materials.

https://www.planningportal.co.uk/in...ombustion_appliances_and_fuel_storage_systems

As Doggit says, if your existing constructional hearth is not deep enough, you're better off cutting out the floorboards and building out with a proper footing.

 

[tomfe]

Just crack on with it and lay the concrete over the floor boards. Extend your dpc over the boards so it does not slip down the gaps.
You could stick a bit of rebar in to help with cracks but I've seen this done so many times.

 

[geraldthehamster]

From Part J:

“2.25 Combustible material should not be placed beneath constructional hearths unless there is an air-space of at least 50mm between the underside of the hearth and the combustible material, or the combustible material is at least 250mm below the top of the hearth (see diagram 25)“

 

[tomfe]

https://www.google.co.uk/search?q=glass+hearth





Uhmm

 

[lostinthelight]

https://www.google.co.uk/search?q=glass+hearth

View attachment 136983

View attachment 136984

Uhmm

Different rules apply for free standing stoves to ones installed in a fireplace recess?.
litl

 

[tomfe]

Different rules apply for free standing stoves to ones installed in a fireplace recess?.
litl

Not really, you still need part J and distances between combustible sources.

Op is installing a free standing stove.



By the way I am not saying any of these installs conform to BR but they are what's being done and Heatas registered installers are doing this type of install also.

 

[Bilabong007]

I think it depends on the stove.

Mine states in the manual it doesn't need to be placed on a constructional hearth and can therefore be placed on any non combustible material eg glass of a suitable size.

Quote from manual:
SUPER IMPOSED HEARTH
In certain circumstances Building Regulations allow for a super imposed hearth. This must be a minimum 12mm non- combustible material e.g. slate, glass, steel. This stove comes with 72mm minimum leg detail which does not ex- ceed 100°c and therefore is suitable for a Super imposed hearth. With the addition of Woodwarm accessories such as legs, plinth, pedestal, the hearth temperature is further reduced.