How to Use Roofing Felt for Underlayment on Laminate Flooring. Floating floors can be installed over any existing hard floor surface, but should have an underlayment between the laminate flooring and the subfloor. You can buy laminate underlayment, but if you have a bunch of old roofing felt, it works just as well.Click to see full answer. Similarly one may ask, can roofing felt be used under hardwood flooring? Staple or Nail Down Installation With a staple down or nail down installation over a wood subfloor using solid flooring or engineered flooring, it is recommended that an underlayment of 15lb. black felt paper for flooring installations over wood subfloors looks a lot like roofing paper, but it is very different.Additionally, do I have to use underlayment with laminate flooring? Underlayment for laminate flooring is a must. Since laminate is a floating floor, it must be evenly distributed across your subfloor. Underlayment is what allows the floor to float, gives it stability, support, noise reduction, and supports the locking systems in between planks to assure the sturdiest flooring project. Besides, is roofing felt toxic? Vapor Concerns Concerns about roofing felt stem from the bituminous impregnating agents (tar and asphaltic bitumen) and whether fumes from the felt may rise into rooms. Roofing felt is not considered toxic and is not listed as a carcinogen. Under normal use, the product is considered stable and nonreactive.What can be used under laminate flooring?Laminate underlayment is a supplementary pad that is installed under laminate flooring to help the laminate planks lay smoother, connect better, and feel slightly softer underfoot. Underlayment is either attached to the bottom of the laminate flooring or it comes as a separate roll of polyethylene foam, felt, or cork.