Laying Floorings-Concrete Preparation

Hi,

Just moved into a new house. We bought 160m2 of hardwood floorings we will install ourselves as a floating floor.

We bought the Bunnings Floating floor installation DVD. It's pretty good and explains it pretty well.

My questions is, I'm trying to get the concrete floor even, according to the DVD I shouldn't have more than 3mm of play at the end of a plank for 2 metres of length of flooring. I've got a real hard time figuring what a hole and whats a bump in the concrete. I've got self-leveling cement to fill holes and I've got a grinder to cut bumps but really the more I grind, the more the bump seems to move in other directions but I still can't get the floor level.

What do I do?? :? Does is really matter if there's more than 3mm of play in the planks once they're laid on top of the foam sub-floor?

Should I just pour self-levelling concrete everywhere and pray it'll magically make the whole floor flat?

Bump, no one does any floating floors around here? :-

G'day.
To be fair, It is the weekend.

Wait until tonight or monday to see if you get replies.

The floories don't like having to talk work on days off.

Sorry, I don't do floaters.

Hopefully some floories are hanging around here today :D

Hey - I'm no floorie, but I have just spent way too much time over last couple of months crawling around on my knees levelling a cement floor for tiling.

Sounds like you are doing it by sight (??). First thing you need is a "straight edge". You just need a long piece of wood or metal with a straight edge, preferrably longer than 2m (your plank length. Some good spirit levels are straight enough (though not cheap ones).

My father-in-law is ex-builder (and perfectionist) so he picked one out from some pine scraps I had. Surprisingly I can tell what is straight enough now (with practice) - just look down the edge like pool cue, or better still hold up against a known straight edge or surface.

Then lie this down on your floor and look for the dips - the gaps between edge and floor. Or if it rocks (or the ends are suspended) it is a bump or bumps - get right down and see where it is pivoting - mark this and grind it. Some times it helps to have little marks along the straight edge to see if they are moving up or down as you rock it - this helps narrow down the pivot point.

I think you are better off grinding a little too much and self levelling than leaving a bump for the planks to bow on.

The self levelling took me a few goes and I rang the Davco (brnad I had) help line after 2nd attempt - they were helpful. Make sure the mixture is runny enough. the suggested mix on bag was too thick in my case. I have seen, on the web, a bag that came with a tester - like an egg ring, you filled it and then removed ring and measured the spread - a certain width then the mix was good. Great idea, but alas I had to use trial and error and 2 bags ($30+ each).

160m2 seems like a big area to just level the whole thing. Be careful of being too fussy - 3mm is quite a lot, but on the other hand you need it level. I got sick of it and used a LOT of tile adhesive to make sure the 1-2mm here or there didn't stuff me up, but I guess for floating floors you don't get the option.

Hope this helps.

Paul

Thanks very much, that helps a lot. I do have a straight edge and I've been down on my knews looking for gaps and all and rocking my straight edge everytwhere to find the gaps.

Looks like I'll have to get more aggresive with the grinder from the way you say it. It's just plain confusing as this floor looks like it's compretely covered in bumps and gaps. I can't seem to find flat areas. This is going to be very frustrating if I have to fight it like that for the whole house.

If you've got mor tips please keep them coming :U

The bathroom I did for tiling was ~6sqm but the dining room I am going to do for floating floors is about 18sqm so I am really hoping it is in better knick, as the bathroom took a while.

160 sqm is HUGE. Sounds like you want a a floor sander with a masonry grind pad - and a breathing apparatus (joke not tip :wink:).

You might be better off wearing the cost and self levelling the whole thing. I would certainly research how to do the self levelling though - maybe even practice somehow. Not sure if it is meant for such a large area.

Hopefully some pros might jump in here and let you know.

Awful job - especially when you just itching too click-clack the floor down - I empathise.

It's indeed huge, it's the whole house appart from the wet areas :) I don't mind self-levelling the whole thing. I just want to know how to get it level if I'm going to dump all that cement on the concrete floor

I'm thinking of getting those 2-3 metre long concrete flattener thingies (Screech?:? is that it?) and just spreading the whole self-levelling thing in the room and use that long flat bar to spread the cement all over the floor. Hopefully that should flatten it enough to fix that when the cement dries up.

Anyone ever do this? Does it work?

G'day.
For that size job, I'd be getting a Pro to do it.

Ardex leveling compound is the best to use for leveling uneven slabs.

It's nice and runny and will self level.

Thanks for the levelling compound tip. At this moment I'd rather take a week or two of vacation time with the wife and do this together than pay someone 4-5K's to do this. I'd much rather keep the money in my pocket. There's tons of other expenses that come with a new house. In our case it's our first house. There's lot of stuff that we need to pay for: build a driveway, lay concrete for a patio, turf ect... We want to save cash where we can and since we're handy we'll take care of the floorings. :)