Repairing concrete fireplace hearth after removing gas fire

[Teeg84]

Hello there,

I am in the process of opening up an old gas fireplace and have come to the point where I need to repair the concrete hearth where the gas line was. As this will be my first cement job ever I'm hoping someone can offer some advice:

- should I rip up the remaining, good cement and start over or simply repair where the hearth is damaged?
- what mix should I use? Hole is between 1-2.5" deep
- what should I use to 'contain' the cement, especially the left hand side that sits alongside the floorboards?

Here is the fireplace as it stands:

Untitled

• Teeg84
• 19 Jan 2015
• 1

Any help appreciated!

Thanks,

James

 

[ree]

What do you intend to use the fire opening for?

To prepare a safe and Regulation hearth:

Crack out the remaining concrete and dig out any loose earth.

You should probe under the edges of the boards and trimming joists to search out any fungal rot dmage - you could also crawl under the floor and examine the timbers.

Concrete mix of 3:1 S&C about 100mm deep on a layer of plastic eg. a ripped and spread rubble bag.

Note: presumably a Gas Safe capped and tested the old gas pipe?

 

[Teeg84]

Thanks Ree.

Eventually I intend to have a wood burner fitted with slate hearth. For now I just want it repaired.

Floorboards are currently loose after doing some other work underneath. Will be screwing them down at the weekend.

Can I ask what the plastic is used for? Also, I will be filling to whatever depth floor level is. Should I leave the floorboards in place whilst I do this to keep the shape of the cement?

Thanks!

 

[ree]

If the boards are loose then lift some and check the timber esp where the joist tails go into the wall pockets, & around the hearth.

The plastic is a damp membrane - just a precaution - to stop any damp from the hearth fill reaching the hearth trimming timbers. You could lap it up to the edge of the boards before the concrete is "poured".

Sweep and smoke test your flue(s).

Read up on sites like stovesonline.co.uk (& on here) for a heads up on stove installations.