how to avoid levelling with screed?

[sweeneyuk]

I have a concrete sub floor that has low areas of about 18mm at worst but want to avoid levelling with compound.

my idea is to cover the whole area in some kind of insulation like fibre board (may double up to get say 25mm) or extruded poly, expanded poly, kingspan etc
then board whole area with 22mm t&g chipboard, then 10mm foam & laminate.

Is this mad or okay? can the isnulation form the vapor barrier?

Have a pregnant wife & nowhere to move everything to screed the whole floor which i imagine will need to be done in sections with battens etc & wont be able to live here until its all dry.

 

[WoodYouLike]

How about battens instead of layers and layers of fibre board. Then 18mm plywood and then your laminate floor?
You could "level with different height in battens, taper off etc.

 

[mac391]

It's Mad sweeny,,

firstly, to use any batten, timber or kingspan, you need a DPM on top of the concrete slab or it will absorb moisture and deteriorate.

If it's only 18 mm out, you can use a levelling screed up to 20mm thick that you can walk on in about 2/3hrs. It would only take 4/5 hours to complete after allowing for the primer to dry.

Then you could lay DPM underlay & laminate straight on top.

Battens just wouldn't work fullstop if your floor undulates and you would also puncture the DPM when fixing to the concrete.

 

[sweeneyuk]

i removed a partition wall between the hall & living room & discovered the hall was slightly higher than living room at one end but becomes level after a few metres.

also under my stairs which was boxed in but now part of the open plan area, is also higher than the hallway.
again not by much but too much to laminate over.

if i do have to screed the whole lot how do i go about it?

do i need to prime the floor 1st?

do i just keep dumping a load of screed & spreading to let it settle or do i need to put in a few battens to make sections then once dry fill in where the batts were?

cheers

 

[mac391]

You can in theory do it one go but not a great idea if you've never done it. you also need to add aggregate to the screed if it's deep.

My suggestion would be to prime the floor (with diluted neoprene primer) and lay the screed in parts. Screed the dip between the hall and lounge room first if it's too deep to do the lounge in 1 go, let it go off and apply another coat and a 3rd if necesarry.

Your second description of the room space is slightly differnt from the first but your not looking to make it level (spirit level), just try to get it flat.

seal any holes where screed might escape using decorators caulk and get someone to mix for you. Make sure you buy enough screed, you can work this out from the back of the bag.

I wouldn't use battens but if you feel more confident doing a small area then go ahead.

 

[sweeneyuk]

thanks for the advise.

if i dont use battens how do i do the floor in stages?

the holes where the wall used to be i filled with cement but they slope are sloped due to what was the hallway floor being 18mm higher than the living room floor.

do i just spread the screed out & let it find its own level?

what kind of aggregate should i add? sharp sand?

whats best primer brand & best to buy from?

can i use a plasterers trowel?

 

[mac391]

//www.diynot.com/forums/viewtopic.php?t=80333

Have a look at this..