Levelling floorboards for engineered wood

[jacoscar]

I’ve started installing 14mm click fit engineered wood in my first floor (which has floorboards)

All I did for preparation was screwing down the loose floorboards and replacing the ones in bad shape with 18 mm plywood; I also used a sander to bring down a couple peaks in the floorboards edges (mainly where two joists meet)


I used a 3mm underlay (this one https://www.wickes.co.uk/Arbiton-Ea...Wood-Flooring-Underlay---10-2m2-Pack/p/191372) and started installing the planks parallel to the existing floorboards


After completing the first room I realised the floor squeaks when stepped over, and in some cases it even moves by 3 mm (measured using a 60cm spirit level and puttin my weight next to it)


The subfloor is clearly not levelled and maybe I haven’t used the correct underlay


I am thinking of taking the planks up (I should only break the 6 that I’ve had to glue, but save the rest) and do whatever is necessary to stop the floor from moving and make noise


I am thinking of using a planer wherever there is a step between two adjacent floorboards and then nail down some 3mm hardboard (2.5£/m2) and maybe use a different (thicker? Fibreboard?) underlay


What do you suggest?

 

[Bonni]

I always screw the boards down at 400 centres with tongue tite screws. On a concrete floor, prime and glue down.

 

[jacoscar]

I always screw the boards down at 400 centres with tongue tite screws. On a concrete floor, prime and glue down.

I have click fit planks and wooden floor

 

[dazlight]

I’d change the underlay to timbermate excel. Great for wood floors.

The floor needs to be flat as any dips will cause movement which leads to squeaks in a click engineered.

 

[jacoscar]

I’d change the underlay to timbermate excel. Great for wood floors.

The floor needs to be flat as any dips will cause movement which leads to squeaks in a click engineered.

But how? 3 mm ply, 6 mm ply, self levelling compound?

I’ve been told to use 6mm ply, but what happens if there is a large dip in the floor below the plywood so that it is not in contact with the floorboards? I’m talking about an area of maybe 20x20 cm, not just a few mm...

 

[dazlight]

The way we do it.

6mm Plywood the whole room. Ringnailed every 6” and 4” on joints
Then get a 2m long level / feather edge
Mark on floor low spot and screed rheum with
Uzin 196
Fball 700
Bostik flex
Ardex FA10
Tilemaster levelflex

Take a lot of time and can be hard to get everywhere flat and level.

 

[jacoscar]

Do I have to nail the plywood in the centre as well to be sure it’s in contact with the floorboards or just on the sides?

 

[dazlight]

Yes mate. Every 6” over whole board. But edges every 4”

 

[jacoscar]

Yes mate. Every 6” over whole board. But edges every 4”

Ok, and how to you seal the joints and around the room?

 

[dazlight]

Cut up about 2mm short and then use gripfill or a mastic.
Was about to say put this on the flooring forum for more advice. But you have

 

[jacoscar]

Is it better to pour the slc on all the three bedrooms and the hallway together (35 m2) or room by room? And if so, how do I ensure they are all at the same level if done at different times?

 

[dazlight]

Better to do at the same time. Use a pin leveller.

 

[jacoscar]

I was thinking of using Mapei Ultraplan as slc, I’ve checked the instruction and it doesn’t say what primer or sealer to use on plywood

What do you suggest?

 

[dazlight]

Mapei Prim grip

 

[jacoscar]

Mapei Prim grip

Are you sure? It doesn’t mention timber here

Eco Prim Grip is a multi-purpose, ready-to-use primer for internal and external floors and walls and may be used to improve the bond of all types of cement, gypsum and lime-based plasters on substrates made from concrete, brickwork, vibro-compressed concrete blocks, lightweight blocks and gypsum.