The vinyl is VERY thin. A 3mm thickness is definitely going to require PERFECTION. The subfloor MUST BE SUPER FLAT. That is going to cost money. The adhesive application (trowel, notch, size, application, etc) is going to have to be PERFECTION. Trowel marks can and will transfer through thin vinyl like this.

What is your subfloor? Concrete slab on grade? Below grade? Suspended slab (aka apartment)? Plywood? OSB?

Is this a new build or a renovation? What is the current flooring?

What is the wear layer? Is it 12mil, 20mil, 40mil? What are your expectations for this floor?

SJ McCarthy I did worry about imperfections showing through with the vinyl being so thin. Our home is a 1986 Ranch style. This is a renovation. We have lived here for 19 years. There is so many different flooring types in the house now. Ceramic tile, carpet and some very old vinyl plank flooring that has actually held up really really well.

The only thing we replaced when we moved in was the carpet. We started removing some of the ceramic tile last weekend and the subfloor is by far not smooth underneath. Its a concrete slab.

The wear layer is 20 mil. My expectations for the floor is I want it to look beautiful and be durable for the next 20 plus years.

OK...what you want to know is the MOISTURE content of the concrete slab. Your house 'sounds' young but in the building industry it is possible they used the old fashioned 'concrete on raw earth' type of pour. That is to say it may not have a vapour barrier underneath.

By the mid-80's the use of the vapour barrier under the slab was common but not 100%. It is possible your home doesn't have it. That means you need to do some moisture testing. The Calcium Chloride test is OK (ish) but doesn't tell the whole story. An indwelling probe is going to be the best identifier of in-slab moisture content.

The moisture content is SUPER important. It tells you which adhesive to use with your vinyl. Not all 100% moisture-resistant adhesives are actually 100% moisture resistant. They have limits. And believe it or not, the limits are not as high as you think.

If the worst case scenario is in play, you could be looking at adhesive that costs $3/sf. The trowel application must be perfect and the plank/subfloor coverage must be 100%. There is no short cut when it comes to the moisture barrier adhesives.

And if you have a damp or wet slab, be aware that 'capping it' with lot of rigid, non-breathable material like vinyl or stone or tile or hardwood, etc, you *might find yourself dealing with EXTREME moisture levels because the build up of water becomes so high, you find yourself walking on soggy flooring. It has happened in the past...it will continue to happen as long as we have concrete slabs without moisture barriers underneath.

The wear layer on this product, 20mil, is good. It will look 'good' for about 10 years and then start to show that it has been lived on. Of course beauty is in the eye of the beholder. Just because a floor looks a little worn does not mean it isn't durable. In the building industry 'durable' means fully functional regardless of what it looks like. To homeowners 'durable' means 'looks perfect'. You can see where there can be some upset over the use of the word durable.

Who is doing the subfloor preparating? Who is doing the moisture readings? How much of the home's footprint will receive the vinyl? What is the recommended adhesive for the product?

@ Sandi -
I Just left a novel on your other post asking if anyone had installed Happy Feet flooring. Mine is floating, and that can actually be taken literally in some areas of my home where this floor was installed. Very unhappy with my floor! Mostly due to the crap installation.... see other post.