Is self levelling compound the right thing to use?

[KatyMac]

We hade a fireplace to remove and need to fill the hole on the floor now the chimney breast has been bricked up

Do we use self-levelling compound or sand and cement? & if we use the compound which one (looking at Wickes and there are quite a few)

Bump

I’d go with cement personally if the hole is substantial. Levelling compound is more to get the small dips and lumps out of a floor. If you’re filling in a substantial hole then this won’t do the job for you and you’d be better off pouring cement.

What flooring are you planning on using as a finish? as said what is the size of the holes to be filled?

N&C do a latex cement based on that will fill to 50mm, it sets like sand cement but not as strong as concrete.

Flooring, I've suggested laminate as it's a dining room with patio doors to the garden but DD & her partner want carpet so it's carpet!

It's about 1 ft by 30 inches and maybe 2 inches deep at its deepest but less than a cm in other places

Sand and cement would be needed as it’s fairly deep. You could do self leveling on the top 1cm or so. But (I think) self levelling is used to get an even height across a large, whole floor. I think you might be able to make sure it’s flat anyway by using a spirit level as it’s only a small patch.

(Not an expert)

I hope you have left a vent in your chimney to avoid future damp problems.

Cement it. You may also have loose rubble etc I’m assuming in the hole? Make sure you know how to level it all properly as once poured you don’t want to be having to start again and drilling a couple of hundred kgs of concrete out of your living room!

Vent in the chimney breast, and a rain cap thing on the top of the stack

We are keeping one fireplace but blocked 2

Do I need to pva the hole before I use sand and cement (can I buy it ready mixed?) I'd rather use a small amount at a time rather than risk over filling

Is this any good?

I can level it, I can ice cakes too - but it's a faff! God I'm lazy

No loose rubble the fireplace guy hoovered it all up!

No need to PVA. You can get bags of pre mixed cement / concrete from any DIY store where you just add water. Given depth of hole you could go with mortar but cement probably your best bet for a solid finish.

Other thing to consider is cement will transmit water up so you might need to apply a membrane before pouring. Depends what you are filling ontop of. When I took my fireplace out, I installed joists as rest of room on cavity so no need to consider the water element as nothing in contact with floor.

It's a 1950s ex council house and a concrete floor, so I'd hope it had a damp proof already

I better take some photos

It's shallower than I remembered

So membrane then sand & cement?

I'd use self levelling for that. Pour slowly and don't overfill (like my DH did)...

I'd also use self-levelling for that.

Its bucket full or so of fill, it doesn't matter, whatever is cheaper or you can get hold off, just wet the floor first.

Carpet and underlay will hide any imperfections in level, within reason!

I’d be inclined to use a membrane and then you could either cement or self levelling. I’d still go for cement personally but probably much of a muchness for a hole like that. In the rest of your floor joists with cavity or is it solid cement?

It's a solid ground floor with wood on top

Its too thin for a membrane which would serve no purpose, what are you trying to stop?
If the old hearth is below ground level, then you have other things to worry about.

I was just going to use self levelling and be done with it

I assumed the hearth would be on top of the damp proof course installed when the house was built

I just need the easiest, laziest way to get it done

Yep, no point over thinking it, its not structural, just don't over fill.

If its a 1950s house there will be no damp proof membrane under the floor ( concrete)

Assuming the hole is directly in the ground then you are trying to stop the passage of moisture up through the concrete? Nothing to do with structural and damp proof course on external walls won’t stop water tracking up if laying concrete directly onto ground inside the room. If you’ve got a concrete slab as your subfloor then you are betting that any damp proofing was continued under the hearth too. For the sake of a tenners worth of DPM I’d be making 100% sure by laying some.

The concrete under a hearth is usually in the order of 250mm thick min, the fill required is 40mm to 5mm, the fill will crack if a dpc is used, there will be no bond with the existing concrete.

If there is DPC in the floor, its way deeper than this & if there isn't, what about the rest of the floor beyond the hearth?

There was no previous dpc removed, so there is no point just randomly adding some.

It is a small defect in the floor following chimney removal, over thinking 101.