Hi to all the pros,

I am about to start a new big project, I figured would best to see if all the pros out there can give me some advice, warnings or pointers... anything is much much appreciated... I am not new to working with wood, but have not installed floors by myself as of yet...

OK so here goes; I have ordered approx. 450 sq ft of pre-finished engineered olive-wood 2-layer floors (T&G) from Italy for the living room and kitchen floors. Also approx 50 sqft of unfinished olive-wood planks to make a kitchen counter-top...

For the counter-top project, I plan to create a 1/2" surface using pocket holes (kregtool) and then glue/screw it on top a 3/4" furniture grade plywood base and make a trim from the olivewood to cover the edge, then sand it down all the way to 600 and coat with food-safe mineral oil/beeswax

For the floors my original plan was to glue+nail to the sub-floor - the manufacturer did not recommend to install floating because its only 2 layers and may cup if not fastened but i have recently discovered that the living room sub floor, while in level with the kitchen plywood sub-floor, is made of 3/4" OSB

Should i replace the OSB sub-floor with plywood or should i install new plywood over the entire kitchen/living room area? that will raise the floor by that much, but its not a big deal... the only thing is, i will have to also cover the kitchen to maintain the same floor level...

if putting plywood over the OSB is OK, what thickness should it be? is 1/4" fine to hold the hardwood floors or should it be 1/2 or more?

also how can i prevent creaks between the two floor layers? i assume using screws to the joist below for starter, but should i use some felt material between the two sub-floors?? or maybe glue them?


any help or advice on the project is much appreciated
thx!!

Ok so the manufacturer recommends gluing the floors to the plywood/OSB in addition to nailing them... here is the reasoning i was given:

"Olive wood is a very strong difficult wood specie in respect of oak flooring saying that only nailing down this type of wood floooring can have risks of movement during change of season"


anyone can comment on this? also they say they flooring can be glued/nailed on to the OSB and there is no need to add plywood material - how risky is that? i read somewhere that the glued floors can just come off with chunks of OSB material...

I have no experience with olive wood so I don't know its characteristics. However, you said it is engineered and that means it should be very stable if acclimated to the room properly .

Normally, fastening through the tongue and groove is adequate but in the case of OSB, gluing in addition to fastening is better.Also, the width of your flooring makes a difference. With boards 4 inches or wider , many of us contractors opt to glue.Sometimes a full spread or in some cases, just strips of glue perpendicular to the direction of the floor will suffice