Levelling ground floor [repost]

[adibell]

[reposted here as it seems much more active]

Hi,

I’m not looking to tile the floor, but feel this forum has some really smart and helpful people who could give great advice...

Our ground floor is made up of quarry tiles cemented directly onto the concrete slab in the hall and kitchen, and then suspended timber in the living room and dining area. We had a wall removed so now it’s an open plan between kitchen and dining area, so now there’s a difference in level where the timber is lower than the QTs, sloping from ~5mm to ~20mm lower. We want to level the entire downstairs floor so we can lay laminate throughout, keeping things as simple and affordable as possible. Digging the whole lot out isn’t really a route I want to go down.

I’ve seen lots of different techniques to combine but nothing seems to be the ‘golden ticket’ answer. So, here’s my current plan, please critique or add recommendations as to whether this should/shouldn’t work and point out if I’m missing something:

1. From what I can tell there’s no DPC below the QTs, so I need to apply one over the top. I was thinking liquid epoxy DPC.

2. Prime the suspended wood floor areas

3. Apply tile backer boards with tile cement over the timber floor areas. Fix at 300mm centres. Maybe use thicker boards where the floor is greater in difference, giving a stepped level closer to the quarry tiles. Not sure if this is ill-advised rather than just using thicker SLC at one end of the level difference?

4. Seal gaps around the edges of the backer boards where they meet the walls using sealant gun to stop SLC escaping.

5. Prime over the top of the tile backer boards with SBR

6. Apply SLC throughout the entire downstairs area. Get someone to help mixing batches of it whilst I spread it.

7. Apply underlay and laminate to [hopefully] lovely flat surface throughout.

Does this sound like it would work, or is it the ramblings of a madman? Is there a simpler option I’m missing?

Thank you in advance!

 

[adibell]

Bump

 

[Qwerty]

Hi @adibell

I'm sorry nobody answered your question first time around.

It sounds like a pretty sensible plan to me. I would recommend that you use the same primer as the adhesive/ levelling compound manufacturer and that you either split the area to be levelled into bays or use height markers (or blobs). Some use offcuts of backerboard set in adhesive, others use building packers. Have a look through the forum for tips on self levelling. Its quite an art to get it like glass!

As for the DPC I would phone the technical dept for the manufacturer you plan to use. They can often write you a method statement of works required or even visit your site if available.

 

[adibell]

No worries! That was a really good and thorough answer, thank you very much!

Glad to hear it’s a realistic plan

 

[adibell]

Just to build on this, would I need to put a damp proof layer over the quarry tiles, but under the screed? I just read something about putting epoxy DPM over the top of screed... Should the screed be laid directly onto the tiles, and then put a DPM over the top of the screed before laying laminate?

Also, would damp proof sheeting be fine here? The epoxy stuff seems incredibly expensive in comparison!

Thanks! Any other advice on this plan would be greatly appreciated.

 

[GoneGuy]

I would prime the quarry’s and lay slc ( use same manufacturer primer and slc) then because your using laminate flooring I would use a underlay which also has a vapour barrier built into it and seal the joints with the barrier tape supplied with the underlay. Then install laminate flooring.

 

[adibell]

I would prime the quarry’s and lay slc ( use same manufacturer primer and slc) then because your using laminate flooring I would use a underlay which also has a vapour barrier built into it and seal the joints with the barrier tape supplied with the underlay. Then install laminate flooring.

Awesome, thank you. That seems to back up a couple things I’d read yesterday, and seems a lot simpler.

Should SLC stick to the quarry tiles (with primer) without a mechanical key adding (eg like a plasterers gripcoat equivalent)?

 

[Qwerty]

Use a primer such as Mapei Eco Prim Grip or Tilemaster Prime+ grip