Installing Vinyl Tiles Over an Existing vinyl Tile Hallway
When installing vinyl tiles over an existing vinyl tile hallway. It is better to attach luan plywood over the sub floor with ring shank nails. Depending on the existing floor if has 1/4" Masonite+1/8" vinyl tile on top of that I will add 1/4" laun plywood + 1/8" vinyl tiles. The best option is to use ring shank nails which are made exclusively for this purpose.
Some people that prefer to use vinyl have used 7/8” staples. When you install thin plywood it is best to have a staple gun made just for installing ¼” and also luan which has been pre-coated for 7/8”
With all underlayments, the fastener should penetrate the underfloor by ¾” (1.9cm), but not protrude through the underfloor by more than 1/8” which is about 3.2mm. If you have an underlayment which is replacing or being placed over an old floor covering like vinyl then the thickness of the existing flooring should be taken into consideration as well when you decide on which nail and the length of the staples used.