What can I do with this floor?

[Steve]

Ground floor of a 1950s house. Cracks everywhere. Where the cracks are the floor has lifted slightly too. Enough to notice through the carpet.

Is self leveling an option? Or screed of some sort? Worth mentioning we're probably taking most of the house back to brick at this point so in a good position to fix this now.

Cheers.

 

[dazlight]

Looks like magnesite that.
Is it about 1" thick ?
If so it needs to come up the either screeding compound with liquid Dpm
Or Ashpalt

 

[Steve]

Looks like magnesite that.
Is it about 1" thick ?
If so it needs to come up the either screeding compound with liquid Dpm
Or Ashpalt

Magnesite? Never heard of it. Is that something they used to finish concrete floors? So this should be a thin layer and then the concrete subfloor below? Will that be in as bad condition? Or does this stuff just crack on its own?

 

[dazlight]

Yes mate it was a finish. But you can't lay over it.
That's it it is. Hard to tell from pics

 

[Steve]

It sounds like it is that. Just been reading about it. Couldn't help but notice the A word. Asbestos. Oh no. Was it commonly used in this?

 

[dazlight]

Didn't think it was in that but not sure.

 

[KenGMac]

Steve, good evening

Could be that your floor is suffering from Sulphate attack?

Occurs when the under floor fill is comprised of Colliery Waste or similar?

Do you live in an old now redundant Coal Mining Area?

Ken

 

[Steve]

Steve, good evening

Could be that your floor is suffering from Sulphate attack?

Occurs when the under floor fill is comprised of Colliery Waste or similar?

Do you live in an old now redundant Coal Mining Area?

Ken

Yes I do. But not sure about sulphate attack. I think the previous explanation is right, magnesite. I'm going to get someone in to look at it. If it needs digging up its getting done now.

 

[Steve]

I had a bit of a chip at one of the crack joints earlier. Indeed it is a screed of some sort, around 10mm thick. Matched the description of magnecite exactly.

The concrete below is also cracked and probably lifted too at the cracks, since the magnecite doesn't sound hollow at all.

Question is, once I have removed it all what do I replace it with? Does this form the damp barrier of the floor?

I don't mind raising the floor level by an inch or so if I need to, since the front door has a raised plinth below it for some reason that I'd like to level with.

 

[dazlight]

I'd take it up and get a coat of Ashpalt at 20mm

 

[Steve]

How does an internal ashphalt floor work? I cant help but think about road surfacing and strong smells.

 

[dazlight]

It's similar really.
But more smooth.
Goes on hot at approx 18-25mm. Dries in a few hours. Acts as a damp proof membrane.
Just had some done at a job. It cost £350 for 17m2 room.

 

[Steve]

Would any builder be able to do this? Or do i need a specialist of some sort?

 

[dazlight]

You need a Ashpalt firm. I use one in Liverpool. Just google it

 

[Steve]

Sorry, a couple of questions again.

Why do I need asphalt?

If the floor is dry can I just use a liquid screed mix? Even DIY it? I could hire a mixer.

My concern is the undulations/cracks in the floor are quite bad and a 25mm layer of asphalt my not take it out, and no tarmac suppliers local to me mention internal work.

I'm thinking 40mm of (something) might be better. Could I lay semi dry screed at that depth?

Next door told me they left their flooring as it is, but had to use carpet in the living room where the issue is worst in both houses.