Levelling up

[John Cartmell]

I have two adjoining rooms that are now one. The floor levels need to coincide but the concrete floor is lower than the wood-on-joists floor by about 50mm. An option we are considering is to lay a Nicoline hardwood* floor throughout. What are the options to bring the concrete floor up to the level of the wood-on-joists floor? What are the problems of laying a floating floor across the two different types of base?

*Floating floor similar to laminate flooring but T&G solid wood sheets.

[Rob Morley]

Fix battens to the concrete like joists, and fit T&G or particle- board flooring on top?

If you do it like I said there won't really be two types of base.

That will be engineered hardwood then.

[Michael Mcneil]

He said it all. Get extra wide treated battens and you can use 3/4 ply but if you skimp on the battens you will need to fettle and fart with it or use pricier thicker boards.

[Michael Mcneil]

Get some offcuts to try what you need before buying.

If they won't give you some, you are in the wrong place anyway. Go to a decent supplier. You need an SDS too. They are V cheap these days.

[Phil]

For 50mm you don't really have the thickness available to batten & board it. Cheap solution: lay two thicknesses of 1" chipboard, or screed the floor.

[Rob Morley]

Why ever not? The flooring will be less than an inch thick, which gives you more than an inch for battens. As long as there's sufficient thickness to nail down (and as long as you use widish battens so they're unlikely to split) there won't be a problem.

[Phil]

"The flooring will be less than an inch thick"

Have a look at how thick your floorboards are...

[Ian White]

A related question (which is why I'm not starting a new thread):

I want to lay 19mm solid hardwood flooring directly onto a concrete floor that is almost completely level, and also very dry. I will be laying a combined damp-proofing membrane and 3mm foam underlay, which will take care of condensation and any small irregularities.

However, the floor level rises by more like 6mm near the corners and some of the walls. This is probably less than 5% of the total floor area, so it doesn't seem appropriate to build up the level in the remaining 95%. Can this be compensated by shaving the undersides of the boards to fit, where needed?

[Rob Morley]

I already know how thick my floorboards are. How thick do you think they are? And how thick do you think the flooring (whether chipboard or softwaood T&G) that you normally buy from a BM is?

[Phil]

Thick enough that your battens will be thin enough to split when nailed trhough, or give you a bendy floor if you use any thinner flooring.

[Rob Morley]

I just knocked some 1.5" round wire nails through some 18mm T&G and

18x38mm sawn batten. If you're near the edge or end of the timber there is a tendency to split (more so with the T&G than the batten), but if you knock the point off the nail first there is no problem.

[Phil]

Knock the point off a masonry nail? Lol!

[Rob Morley]

Why would you want to use masonry nails for fixing two pieces of timber together?

[Phil]

So they are fixed to the (concrete) floor....

[Rob Morley]

No More Nails or similar will do fine for fixing the battens to the floor.

[Phil]

Expensive & smelly....

[Rob Morley]

£2 a tube for solvent-free Gripfill