screwing down ply to level concrete floor

[theflyingpig]

hi all,

having read over some previous posts I think this might be a better solution to level out my concrete floor (probably about 10 mm fluctuation)

a couple of questions:

what thickness ply should be used?

I'd want to lay a DPM - presume this goes under the ply?

whats the best way of fixing the ply down and at what centres?

I'd be wanting to float a real wood floor over the ply . . .

thanks!

Huey

 

[theflyingpig]

oh, and has anyone tried packing ply level with shims to get the floor level?

cheers

 

[mattysupra]

first of all why you putting ply over concrete? its not meant for this job. your better of laying a leveling screed. i tend to use uzin or f-ball water based product. with 10mm run out i would fill in dips and bring level as good as possible and then do a full screed over top when dry to bring to perfection. as for dpm, well if floor reads below 75% rh you don't need to do anything to subfloor apart from prime before screed. if reads above 75% then i would use a surface dpm first. not a plastic sheet! epoxy resin or a new product on market called creem. need any more info let me know.

 

[theflyingpig]

mattysupra


you sure sound like you know what you are doing . . the ply was jsut an idea - clearly a bad one! My plastering skills leave alot to be desired so I was trying to avoid anything that involved a trowel. I understand the levelling compounds do not exactly "self level" so presumably it takes some skill to get the floor level.

a couple of questions if you don't mind:

how thin can the screed be?

how can I measure the moisture content?

where is best place to buy the products you mentioned?

many thanks

Huey

 

[mattysupra]

mattysupra


you sure sound like you know what you are doing . . the ply was jsut an idea - clearly a bad one! My plastering skills leave alot to be desired so I was trying to avoid anything that involved a trowel. I understand the levelling compounds do not exactly "self level" so presumably it takes some skill to get the floor level.

a couple of questions if you don't mind:

how thin can the screed be?

how can I measure the moisture content?

you need a hygrometer to measure moister in sub floor. It must read less than 75%. It really needs to be a proper flooring one tho as it has a air gap and is sealed to floor for 24hrs to take the reading. Not sure if you can hire one? you can buy a f-ball one for about 100 quid. As for the screed if you use f-ball or uzin waterbased you cant go wrong with getting it level. It really is like water when you tip it on floor. You also really want to do min of 3mm thickness. As for prima use f-ball 131 neoprene primer. If you do need surface dpm then also f-ball can supply you f75 or f76 epoxy. As for where to get it all from well you need to find a wholesaler who stocks f-ball products. I dont know anyone around london so cant help you there.