so we ripped up our flooring down to the subfloor which is planks that have some spacing.the guy who came buy to give estimate said we need to lay 3/4" plywood over it but BC type plywood and also out some sort of felt paper over it ( forgot exactly what type he said). does this make sense?

also I didn't tell him we where going to get the wider planks( were buying) he probably assume we were going to use the same 1" that were ripping up on 1st floor(didn't get to rip that up yet). if it is the wider planks ...say over 3" it has to be glued to, correct?

thank you.

Your other post said you wanted to DIY it.

was going to but decided it might be better to hire someone

Get a couple more estimates.

ok. so how does that help me with my question?

The felt paper he was talking about is a moisture retarder which goes between the subfloor and hardwood to slow the movement of moisture. The previous floor was on top of the subfloor boards he wants to cover with 3/4" plywood....ask him why? Adding another layer of subfloor will raise everything......will the new floor extend to the stairs, if so it will change the rise from last step which could create a variance which is outside of code. 3 inch wide flooring can be nailed and not glued. Maybe check out the book I mentioned in your other post......it will explain a lot of this stuff.

I did he said because the planks have spaces between them. Also he said he would just raise up the bull nose on the last step. One guy said to put felt to prevent squeaking. Tell you the truth I'm can't who really nose what their doing and if I'll get a quality job. I'm not calling dedicated hardwood guys. I put an ad on Craigslist. Thanks probably part of the problem. lol.

There are building codes for stairs. If you raise one step you could create a variance which could take things out of compliance. The felt will not prevent squeaking....this is caused by boards rubbing against each other or against nails in the floor. Before plywood was invented hardwood flooring was installed over planks.....if they are in good shape and secure should not be a problem.

thanks a lot can't tell you how much I appreciate the feedback. yes just about all the planks are in fine shape there are few that need to be replaced. so even with gaps between planks it's okay to install hardware right against planks?

also how do you avoid nailing into the spaces between the planks?
watching some videos I actually think I can DIY this hardwood prefinished plank job myself if I have the right tools.

How thick are the subfloor boards? In relation to the floor joists, what direction are the subfloor boards installed e.g. perpendicular or diagonal? How wide are they?

I'll let you know when I go there tonight. thanks