Looking to find out at which point and time is edging and sub-floor underlayment installed in a new construction process. Also would 1/4 plywood be sufficient for pretty much any floor finishings or am I in the woods on this one(overkill or unnessesary). We were thinking of floating floor for now but will eventually upgrade to hardwood or tile down the line and underlay is not something I'd like to redo. Thnx.

If you plan on having a pro install the tile, I recommend going with whatever product they recommend. We used to use Luan for all underlayment, but there have been some problems with the product & some installers won't stand behind it. We've also used "Ultra Ply". In our last project they used the plastic mesh under tile & 1/2" P&TS (plugged & touch sanded) plywood underlayment under the kitchen Marmoleum. BTW we use 3/4" Advantech over 16" OC joists for the floor sheathing, and install hardwood right over that without another underlayment.

I am planning on doing myself which is why I'm asking. About the sub floor, I've got 3/4 t&g w/ 16'' o/c I joists.
That being said hardwood will be down the line, for now only floating floors due to budget reasons. Would a simple foam bad be sufficient for cusioning and sound control for lower floor.
At which stage do you edge the sub floor to eliminate the joint lumps.
Thanks for the feedback.

There are lots of different underlayments out there as well as of course regular Lauan.  I would never recommend Lauan - its just a matter of time before it blows up on you.  What part of the Country are you in?  THere are two products SurePly and a composite Fiber Board product that wokrs great.

Let me know where you are at and I can offer you a receomendation.

Sam

I am located in Canada,Ontario.
If an enginered hard wood floor is applied is an underlay necessary? What consequences am Ilooking at if no underlay.
Thnx!

Well that certainly changes everything. I thought that you were installing tile from the string above. Engineered Hardwood floor is fine over a level firm sub-floor with a vapor barrior/sound deadening underlayment.

Regards,

Sam