We are planning to install about 350 square feet of Armstrong Nature's Gallery laminate in my kitchen and breakfast area. It's inexpensive off the rack from Home Depot. It has a thin green foam underlayment attached. I'm wondering if I should supplement the underlayment with the roll stuff? We will be installing this ourselves over well glued, even sheet vinyl which was installed over plywood subfloor. I looked at several local floor shops and this pattern is the stuff I like best. It looks like stone tile.