concrete base in conservatory

[dandt]

I have moved into a house with a large conservatory at back with a concrete floor - not very smooth but seems sound and dry. I dont have enough clearance with doors to build a joist structure so I intend screwing down 1cm thick plyboard and then putting lino over this.... is 1cm thick enough? should I lay down some hardboard sheets first to improve surface before plyboard? is there any risk of cold concrete rotting the hardboard/plyboard? do I need to lay membrane or foam sheet first or even some carpet underlay? [I cant get involved in pouring cement or screed because my wife is very allergic to certain chemical and also we dont have the time/space]
thank you for any advice

 

[noseall]

Lino will be ok onto 9mm ply so long as the joints are secure, i.e. will not move or give. 12mm would fare better but the joints still need to be rigid.

Use wbp ply or better.

 

[mattysupra]

why are you planning to put wooden products for wooden subfloors on a concrete subfloor?

Are you trying to raise the height of the floor?

how uneven is this subfloor?

Normaly you would lay a smoothing compound like water based if needs to be smell/chemical free. Then lay new flooring on this.

 

[dandt]

not trying to raise floor specifically (I just mentioned that it cant be raised too much)
I thought ply would be a quick (cheap?) solution
as I said I havent the time or space to get involved with mixing stuff and making a bit of a mess (cemeting/plastering etc is not my strong pt)..also wife allergic to most of the dusts these products produce..also 2 young kids who pass through conservatory often!
how uneven is the subfloor?...a few dents and ridges...too bad to lay lino straight down and probably not good enough if trying to do a laminate floor, but anything a bit thicker than the underlay for laminate flooring would probably 'absorb' the imperfections
thanks

 

[dandt]

would I need anything between the concrete and ply? I am assuming not from your reply

thanks

 

[mattysupra]

you should not be putting plywood down. You can do if you want, but you will be needing to use 18mm etc and screwing .


Get yourself some smothing compound. Acrylic by balls. Mix it in a bin (black dustbin) outside (3 bags in one go) and get a mate to help you lift the thing inside. Tip it out and send it running it the correct directions. There will be no mess indoors. Read the sticky at the top of the forum first tho as its a bit more involved than my basic instructions.

O and kids will be good to run across it in maybe 4 hours or so.

 

[dandt]

thanks for the advice
I used a latex levelling compound in the end 3 x 25kg bag at about £30 each! I used my green wheely bin to mix it. It wasnt as runny as I'd hoped so I had a bit of a race against time to push it around (I found a sweeping brush to be very useful in the initial stages). Anyway its done the job. I would have liked to use more but I found it very expensive. Ps it has also self levelled my wheeley bin - don't tell my council - it should all break off eventually