Laying a new solid oak floor - help needed!

[thebigo]

Hello,

i've bought new solid wood floor. i was planning to nail it to existing floor boards (on joists), however i have read that i may need to lay ply as the new floor will be in the same direction as the existing floor.
I am now concerned that the floor will be a good 15mm higher than the kitchen floor (which leads into the room in question).

so, my 2nd idea is to lay the flooring directly onto the joists. is this wise? would this need a layer of ply also?

or, is there a nice way to "ramp" the edge of the wood floor (the part which leads into the kitchen)?

appriciate any help on this!

Big o

 

[WoodYouLike]

If you install directly onto joists your:
new floor has to be at least 18mm thick
the joist not further apart than 35 - 40cm
every board has to connect with at least 3 joists

 

[thebigo]

thanks for the reply,

well my boards are 18mm, my joists 40cm apart but they are a range of lenghts (smallest 40cm) so will not be suitable.
i guess i would need to lay ply first: do you think 6mm would be too thin? i was planning to nail as well, do you think i can still do this? i could mark out where the joists lay under the ply and try and nail through the ply into joists?

 

[WoodYouLike]

If your existing floorboards are pretty level then 6mm wouldn't be a problem. Your idea to mark the joist is a good one.

 

[thebigo]

and 1 last thing!:

should the vapour barrier go under the ply or between the ply and floorboards?

is chipboard or mdf an option instead of the ply or are they not suitable?

thanks in advance!

 

[WoodYouLike]

and 1 last thing!:

should the vapour barrier go under the ply or between the ply and floorboards?

DON'T USE a vapour barrier when you are installing on to existing floorboards. This will prevent the normal ventilation and can cause moist, condensation and even rotting of the joist.

So, not between the ply and floorboards and not under the ply.

Chipboard and mdf are both not the best suitable products in this situation

 

[thebigo]

so if no vapour barrier is needed, can i still add insulation of some sort? packing it between the joists or in another sheet form that wont effect ventilation?

thanks for the time you are spending here! you are helping me!

 

[WoodYouLike]

The plywood you are about to install on your existing floorboards will reduce drafts etc already tremendously. Then ontop of this your new floorboards, again is extra insulation.
You can of course add more between the joists, but there is always the risk that will reduce the needed ventilation and could cause problems in the long run.