Here is a picture of one of our Vinyl Tile or LVT

Vinyl plank flooring over radiant should not be a problem provided you follow the manufacturers recommendations. Primary issues arise in some systems with uneven surface temperatures causing the flooring the react inconsistenly to the wide changes in temperature. If you'd like – check out our Install Manual – page 35 – there may be some helpful information for you there as well.

Thank you! I completely agree with both of you. This is an old thread, and I’m not the OP, but I am still working on a solution. I put in a beautiful Karndean Van Gogh medium brown wood look, glue down, but it had visible ripples in it after installation. It turns out when the installer used a high grit sander across the seams of my plywood subfloor, he unknowingly sanded grooves into it that telegraphed up through the 1/4” underlayment and the LVP. Karndean was no support at all, refused to see the ripples and said it was a proper install. The sanded grooves were discovered after ripping the whole floor and underlayment out. The installer refunded my money thankfully but still didn’t admit error. I‘m still looking for another LVP solution that will play well with my stairs, railing that screws into the floor, and open edges. Also, it’s hard to find a nice LVP medium brown in the middle of the gray trend when 80% of the choices are gray!

I have the same problem and would never use this product (Flooring is Mannington Adura) again! My experience in passive solar design gives me the knowledge to understand this products massive failures. Yes ... I have the same color and brand ... and that is not a coincidence. The dark color is very susceptible to any sunlight. The manufacture defines any sunlight as direct sunlight, even through a low e double pain window with a 50% screen/shade blind. This product has all the problems of vinyl decking ... but much worse since it is so thin and no wood content. What happens is that any radiant energy ... like sunlight heats the product to make it more flexible as well as expand it. Having a dark color ... and more insulating layers amplifies the problem. The manufacture recommends no padding or extra layers due to this issue. The ambient heat (room temp) is not the only temp here. It is more about the temp of the vinyl and how much different from the room temp. The angle of the winter sun will actually cause more energy to go passed a window, even though the sun energy in the winter is lower. This is all about the angle of incidence/refraction and can have the same effect on a glazed PV solar panel. A skylight would have more summer solar radiation and less winter solar radiation.... assuming a low pitched roof in a mildly northern latitude. I will have to remove floor and replace with a wood product. Dark colors of trex decking have issues of sagging and being to hot to walk on. It takes so much extra wood framing to support this plastic that you do not end up even reducing the amount of wood in a deck... but instead end up consuming more toxic treated woods. These products are just another way to consume more oil in a wasteful process that costs more than traditional products due to short life and continual replacement. This flooring works great in my 4x4 closet with no window! A small dimension means less overall linear expansion! Koi Solar