Wood in 5 wide and 1/2 thick hand scraped birch. Manufacturer recommends 18 ga 1 1/4 staples with 1/4 crown.
If the vinyl is layed directly over the wood sub floor then yes you ll be fine with that size staple. If the vinyl is atop a thin luan subfloor then go to 1 1/2 staple .The thinner 3/8ths wood take a 1 staple. . This is a special nailer (stapler) that you can rent. Takes some getting use to but works great for engineered wood. Any questions you can e mail me through my avatar. GL
Hardwood flooring usually need some type of material under it to help with moisture and padding. If there is nothing under the floor or just the vinyl then the floor will make a lot of noise when you walk on it. I would get with the manufacturer and see what they recommend you put under the floor. I would also make sure that the vinyl floor does not look like it has mold, water or some other type of damage that would cause the vinyl to bubble and cause damage to your new floor. Other than those items you should be safe to put the flooring over the vinyl.
