Laying engineered wood floor, underlay, glue and secret screw advice

Hi all, DIYer here currently preparing to lay 20m2 of Galleria 20mm Engineered European Nature Oak T&G wood flooring in a ground-floor bedroom. The subfloor (is this the right word?) is 22mm T&G chipboard, which I have glued and 'no squeak' screwed onto battens between 90mm PIR. All of this lies on top of a concrete base (with DPM).

Since I don't need any noise-cancelling or insulation from the underlay I was planning to use a budget 2.2mm extruded polystyrene foam from Screwfix and then put a bead of waterproof wood glue in the grooves and secret screw the grooves to the chipboard. Is this a good plan? If not please give me a better one!

Many thanks in advance for any help

 

I would 6m ply and fully bond the floor or float it on a underlay with D4 adhesive around all grooves. Not sure about using underlay and fixing down together? Not something we would do.
How old is the concrete base? If its new it should of been left to dry before the chipboard went over it?

 

Thanks Merit, the concrete base is ancient so no issue with it drying out. I would prefer to underlay than ply and bond. Do you have any recommendations for a suitable underlay ?

 

Timbermate excell is very good

 

Thanks Merit...after laying this bedroom floor I have a further 100m2 of concrete floor to cover. Architect is saying I should lay PIR insulation boards without battens then float glued T&G chipboard on top of the insulation. And then float glued T&G engineered wood boards on top of that. No screwing or nails at all. Is that something you have ever done or would recommend? I would probably still use battens (and screw the chipboard to them) in high wear areas like the hallway and doorways...

 

I've seen some of the 90's builds like this and have come across a fair bit of damp with this system, maybe it's all changed now but I had to rip my aunts whole ground floor out and redo it for me to lay laminate so I guess as long as the right insulation/method is used then it should be OK

 

Yeah as above. It needs to be dry. Would need a dpm over the concrete. It sounds similar to how the floors are tackled on garage conversions although they normally use battens to take out the levels. A floated wood floor that size will likely needs breaks in it. Check with the flooring manufacturer their recommendation on installation and maximum laying area