I am replacing the vinyl in my kitchen and utility room. After I removed the old vinyl, I noticed it was just placed on the 3/4" T&G plywood subfloor with leveling compound here and there. The existing vinyl didn't have any staining or graining in it from the subfloor. I am prepping for the new vinyl floor per Armstrong's instructions of 1)Leveling using their compound (S-184) and 2)Priming using their primer(S-185). I also will be sanding the entire floor to smooth it out before priming. I talked to several vinyl sales people and most of them say I HAVE to have 1/4" luan, even though none of them have seen the subfloor. I don't agree. I belive my subfloor is in great condition and I won't have any issues. Armstrong's instructions also indicate that additonal underlayment on an existing subfloor is not necessary. Am I right or wrong? Thanks in advance for the input.

 

Older harder inlaid vinyl floors were commonly installed directly to the subfloor. They were stiffer than many vinyl flooring products available today. Today's softer vinyl floors will telegraph inperfections in a subfloor system. The subfloor expands and contracts over the course of a heating and cooling cycle and can cause cracking in the floor patch used in the subfloor joints. A 1/4" underlayment approved plywood is not fastened to the jiosts, but to the subfloor itself and is less prone to the movement that of the actual subfloor. Today's vinyl floors also have a more glossy wear layer that will show subfloor imperfections more so then their ancestors.

 

You'll be fine, as long as it is only a perimeter bond installation. I wouldn't recommend a full spread over that substrate.

 

Thanks for the replies guys. I'm not sure if it's perimeter bond or not. How do you know if the product requires a perimeter bond or a full spread? If it requires a full spread, would I need underlayment then? What would happen if a full spread was used to install the product on the subfloor without underlayment?

 

I called Armstrong today and found out that the product I'm using is full spread. Interestingly, they also said that it does not need additional underlayment. Thoughts? Thanks.