We ran into our first major decision point as we started prepping our kitchen floor (300 SF) for the new wood flooring. Upon removing a layer of Pergo and then the sheet vinyl, we discovered that under the sheet vinyl there is a 1/4" underlayment that is stapled and maybe glued (lightly) to the subfloor.

Our options as I see them are -

1) Remove the underlayment (a lot of extra work)
2) Add equivalent underlayment to the rest of the first floor (800+ SF)
3) Have transitions at the two entrances to the kitchen where I am laying wood flooring in the other rooms.

I guess that the ideal would be to have all of the flooring at the same level, which means option 1 or 2.

I am open to suggestions as to which direction to go.

Well, we decided to go with option #1 - remove the underlayment. Quite a bit of work, but it will be worth it to have the floors even throughout the first floor. The biggest pain in this step is pulling out all of the 1" staples that were used to attach the underlayment. They remain in the subfloor when the underlayment is pried up. The glue is old enough that it is not much of a problem.

Is there any harm in just driving the staples into the subfloor and leaving them versus pulling them out? They are about 1" long with a 1/4" crown.

No problem. Just pound them down. BTW, you did choose the right option by removing that underlayment.

Thanks Gary. Pounding them in will be a great timesaver.