[oldhouse49]

living room floor kind of has two levels, one surface is about 1 inch higher than than the other. I want to put on an other layer so the surfaces are level. what kind of cement should I use. For prep work , should I scrub the surface with some acid solution or do I need to grind it? The surface seems to have some kind of paint (see attached). thanks

 

[stadry]

grind off the paint, lay down an epoxy vapor barrier IF its slab on grade, build to elevation you need w/wood,,, this isn't a good prospect for diy work impo

 

[stuart45]

There are some special screeds that can be used at that thickness, although they may not be available in your area.
http://www.screeds.ronacrete.co.uk/screeds/polymer-screeds/ronafix-pre-packed-screed-6-50mm

 

[stadry]

haven't seen thuse here, stuart,,, is that a true screed OR a filler panel ? guess it depends on how 1 defines 'screed',,, i'll look for them at world of concrete - don't recall seeing them the last time but

my thoughts on this - either extended polymer-modified cement, bonded, OR unbonded overlay,,, pm cement's going to be expensive; bonded requires more prep than just dia grinding & will probably exhibit random cracking when done; or the unbonded

1 could also hire in a gypcrete crew

the easiest for a diy'er is, imn-s-hfo, plywood on top of wood

 

[stuart45]

What we call a screed here is about 3 inch of sharp sand/cement laid semi dry on top of the concrete floor slab to get a really flat finish. Nowadays the insulation boards are often placed on the slab first and then the screed goes on top, but the insulation can go under the slab.
There are other screeds used now such as wet self leveling ones for underfloor heating, or thin ones.
However I agree that plywood is the easiest option for DIY, and also the cheapest.

 

[oldhouse49]

forgot to mention, I'll be installing tiles on the entire area afterwards, so plywood may not be a sound choice?

 

[stuart45]

Plywood is normally well screwed down on timber floors to make a solid base for tiling.
Years ago tiles were laid on a mortar bed, lime/sand and later OPC/sand. Wall tiles were also put on with mortar.
It does mean that a really uneven floor or wall can be made straight with this method.
I did use this method on my own house years ago when marrying up 2 concrete floors with 3/4 inch difference.