Timber Floor on top of uneven concrete slab

Hi Guys

I have a workshop slab (6m x 9m). The problem is that it is not level in the centre. It "dishes" and is uneven.

I would like to install a timber floor to make the floor level. What is the best method to lay a floor directly on top of a slab?

Can I forget bearers and just lay the joists (6m) directly on top of the slab and the stick pieces of fibro under the 6m lengths to get the correct level and then simply lay some sort of sheet flooring?

Any help and ideas would be great!

Regards
Greg

G'day.
Use a self leveling compound. You pour it on and it runs to the low points and fills them. It's used all the time by flooring installers.

What are the names of some of the self leveling compounds? And do you know what it costs per sq m for the materials?

Thanks for the information.

I was thinking of using self leveling stuff but I thought that they would only fill upto 5mm. I have troughs of more than 25mm.

I will ring a few suppliers and see what they suggest.

Thanks
Regards
Greg

The self levelling compounds can be used in layers to build up. They can be expanded with sand too if you have deep sections to fill. Bunnings stocks Lanko , another brand is ardex.

Cheers
Pulse

Hi Guys

Looks like I am going to lay a timber floor on top of the uneven slab as I like the idea of walking on timber and not cold concrete. It will also mean that I will be able to simply screw or nail directly into the floor when I am building my new benches etc.

I have a few questions:

The area is about 6m x 10m and I am planning to lay the joists to span the 6m and Dynabolt them to the slab with suitable packing to bring things level.

1. I am thinking of using 70mm x 45mm framing pine...any problems?

2. I am thinking of using 2400mm x 1200mm x 21mm T & G Plywood Flooring (Mr Plywood). This will enable me to use 600mm centres......any problem?

Thanks for any help you guys can provide.

Regards
Greg

I would go with 450 centres, my last shed had 22mm chipboard flooring at 450 centres and with the weight off the machinary you sometimes notice a bit of flex in the floor

Yeah, I was thinking that myself.

I assume you had T & G Particle board flooring? Did you have any problems with it?

Quote:

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Originally Posted by lateral

I assume you had T & G Particle board flooring? Did you have any problems with it?

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Yep that's the stuff I used, didn't have any dramas with it, apart from where my lathe was, but that was mainly in the bearers and joists

Don't forget to glue the yellow tongue to the bearers.

450mm centres would be better and allow more weight to be bourne by the floor.

Particle board for flooring? Bah! Shouldn't be allowed to sell it as such. OSB maybe OK, but plywood best.

Joe

Thanks guys

Perhaps I will use T & G Particle Board and paint it...

Hi Guys,

Just to update you all...

I have investigated using a Self leveling Compound and it is far too expensive to do it properly. i was quoted about $4k - $5k.

Whilst I am capable to make up the floor joists I have decided that I will get a Roof & Truss company to make up a number of "pre-fab" floor modules as per my specs. This will enable me to simply lay them down, level them up then bolt them down in the quickest possible time. All I need to do then is lay the 21mm plywood T & G flooring (I have decided against particle board).

glock40sw suggested gluing Yellow Tongue and I assume that I should also glue the plywood? What is the best glue to use? Also, what are the best screws to use to attached the plywood to the 70 x 45mm joists? What problems will I encounter if I don't glue?

Also, I am thinking of painting the floor white so that it will be a bit more resistant to moisture, look better and reflect more light....does anyone see any problems with this?

Thanks
Greg

ok ok ok here's the go for you bro. You will be better of at 300mnm spaces for your battens. That is a safe span for high load applications. This spacing is used commonly on spacings to stages in auditiorums. If you are going to put machinery on your floor and high load points, then 300 is your answer. 70x 30 hwd battens . Pin your first line down 70mm of the wall and then mark out in multibiles 0f 300. Follow the diagram attached. I hope you will be able to follow the steps.

Ther should be a attachment i attached