Attaching hardboard to concrete floor

russdavies

My kitchen floor is part suspended and part concrete. I have vinyl flooring over it all but will be having new vinyl professionally laid soon. I have hardboard sheets under the vinyl, but because the concrete floor is not totally flat all over, one piece of hardboard that spans across the two floor types lifts slightly and therefore lifts the vinyl by about 5mm which you notice when you walk on it. I believe I used PVA glue to seal the hardboard to the concrete originally, and most of it is still attached but obviously it was not enough for this one piece. Does anybody have any ideas what I could try to use this time? I am somewhat reluctant to use something like Evo-Stik because if it does not work properly, it will be a pain to try and remove it. Thanks

Andy_L

A contact adhesive like evo-stick is what you need.
Alternatively you could look at levelling the concrete bit of the floor with a "self levelling compound".
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wallbash

As you are having new vinyl flooring, we know its not cheap.
My recommendation is some of what Andy L said.
Firmly attach hardboard to the wooden floor, this involves using lots ( and Lots) of copper nails. And then use a self levelling compound on the concrete up to the hardboard.

robv_3

If the floor is unlevel I would be surprised if a contact adhesive worked. You will need something with gap filling properties. I would use gripfil/pinkgrip/etc as there is always some in the van but you may find something better. Whatever you use the floor will need to be held in position until it fully dry. Dence blocks, paving slabs etc normally do the trick.

Personally I would use 9mm or 12mm ply and not fiber board and cover both types of floor. For wood to wood bonding pva and screws.

russdavies

The concrete floor is is slightly undulating. It looks like self-levelling compound was used in the past but did not fully level out hence the undulation. Maybe I'll try the evo-stik approach but use lots of it and weight it well down. Thankyou all for your advice.