new fireplace confusion

[Stubzz]

hi, we are currently renovating our lounge, and we are a bit confused about how to proceed...

we are putting in a marble fireplace surround, do we need to put it in before or after plastering?

Can we raise the hearth using concrete underneath so that when we lay our engineered wooden flooring, we can slot about 5mm of it under so there is no gap (would really rather not have that ugly trim, everywhere else in the room it will be going under the skirting boards).

any advice would be appreciated! Thanks

 

[PrenticeBoyofDerry]

I would plaster wall prior to fitting surround.
The only concern I would have with laying hearth on top of your wooden flooring would be condensation/damp on the wood, which could cause it to rot. This will depend on what is underneath the flooring, might be worth considering placing a bit of DPM on top of floor beneath hearth.

 

[Stubzz]

Only a tiny bit will be under so condensation hopefully wont be a problem. It's all going on a standard floorboards anyway. I'll look into some dpm just to be sure so thanks for the tip.

Just found out the surround screws in on the inside so we'll defiantly plaster first. Any more comments on raising the hearth?

 

[foxhole]

Only a tiny bit will be under so condensation hopefully wont be a problem. It's all going on a standard floorboards anyway. I'll look into some dpm just to be sure so thanks for the tip.

Just found out the surround screws in on the inside so we'll defiantly plaster first. Any more comments on raising the hearth?

How is the hearth constructed?

 

[Stubzz]

It's made from marble, I'd guess it's solid? We've not taken delivery of it so I can't check.

It's this one here

 

[foxhole]

Easier to mount on a large floor tiles which will give the required depth while keeping it level.

 

[Richard C]

What sort of fire is it? There are regulations regarding constructional & decorative hearths & the minimum distance to combustible materials.

If it’s a stove or open fire which is in use, don’t use gypsum plaster or plasterboard within 200mm either side or 800mm above the fire or fire opening, it won’t stand exposure to temperatures of more than 50 degrees & will fail.

 

[Stubzz]

It's gonna be a gas fireplace so it'll get very hot. Would it just be the front face that'll need to be fire resistant plaster or would the sides need to be the same way?

 

[Richard C]

OK, looked at your pic link & you should be OK with a gas fire; stoves & open fires are my experience area & generally have higher heat outputs which can really ramp up the temperature in the chimney breast & surrounding walls.

I assume you’re aware of Building Regulations covering the installation of gas fires & suitable flue liners? Installation of gas fires is a definite “no go” area for DIY.

 

[Stubzz]

So you don't think we'll need the heat resistant plaster? Either way I'll mention it to our plasterer.

It'll all be installed by a gas safe registered person. I just want to make sure it's done so that I can get a better finish on the floor.

 

[Richard C]

So you don't think we'll need the heat resistant plaster? Either way I'll mention it to our plasterer.

I assume the gas fire is around 4 kw max so you should be OK with the surround in place but don't plaster behind it; sand/cement/lime render only. It’ll be a test of knowledge/experience for your plasterer to see if he is aware of the heat restrictions of Gypsum, surprisingly many aren’t which often leads to arguments & tears.

 

[WalksWithTurkeys]

I would check that the surround is suitable for use with a gas fire. Micro marble is an engineered stone, made from crushed stone and resin, and will not tolerate much heat.

Also, if you search round you should get the same item cheaper. I know a local place (near Portsmouth) that does that kind of surround for £400 - £600 depending on style (they sometimes buy end of lines cheap).