Wood Fiber Flooring Underlayment, 6mm (1/4 Inch) Thickness - 90 Sq Ft, Natural Soundproofing Insulation, for Laminate, Vinyl, LVT, LVP, or Hardwood

I was about to lay 3/8" Engineered Hardwood (Flooret Silvan) directly over tile, considered the Steico product and wondering whether I would need to pre-fill the grout lines (~1/4" wide by 1mm deep - tile is 20 x 20). Sunco (whose support has been fantastic!) of course gave a, honestly not unexpected reply, that their std recommendation would be filling the grout lines (not unreasonable). But while not endorsing per se, they had knowledge of users who had not and it appeared to be working out. I decided to go for it and have done a double layer (staggered pattern) over a 1/8" lower tile level and single level 1/8" (3mm) over the main area tile as per the image above. I did a test - with the 3mm product (only, no plank yet) I aggressively pounded /stamped / jumped/ beat on it above the grout lines and could NOT get them to telegraph even to the bottom side let alone through to the top! So I may get some disagreement from the community here on pre-filling but with my test and the fact that the engineered wood flooring in itself is quite rigid, I had no qualms about going straight over as-is. Image shows an area that had a tile field that was exactly 1/8" below the main tile level: I believe house originally had carpet section there and previous owners filled with a different tile, but not fully flush up to the other tile. So for this section I put one layer of 3mm in to exactly fill that section to its perimeter with the other tile, then a complete layer of additional 3mm over everything. I was careful to stagger the joints so they did not overlap between first and second Steico layers, nor the planking joints. (for the plank it's easy - fraction over 7" wide which is not a factor of 24 or 36, so it will naturally not create any joints over underlayment seams.) It is SUPER easy to work - cuts easily. I personally found scissors a better tool than a Blade. And I wondered if it would be more work than 'roll' type underlay which I have used previously. Actually I found it to be convenient - one row of 2' panels would accommodate 3 rows of plank and I could just lay as much underlayment as I chose to work my way across room (while juggling furniture around) The result underfoot is that it feels great - indeed quiet and comfortable, and that is also borne out when witnessing from level below. I am absolutely delighted by this product and would not hesitate to recommend this product to anyone.

This is an outstanding product. When I installed my new laminate floor, I was a little concerned about the sound, your shoes make on the floor that high-pitched clicking noise, but this underlayment material at only an eighth of an inch thick really made the the laminate flooring sound solid like hardwood. The bonus is, you can stack it to fill edge or corner gaps in floor height. The fibrous content of the material is very easy to cut, and you can feather the edge down to almost nothing creating a very smooth taper. I installed it in no time using a few staples to keep it in place and used flooring tape on the seams. Can’t recommend it highly enough. Oh and by the way, it’s about a third the price of the foam underlayment and I think it’s a higher quality.

I used this floor underlayment on a 360 sq ft floating floor. It worked great, installed very easily. You can cut it with a simple swipe of a utility knife and then a bend and the product will break on your line. It WILL make a ton of green dust everywhere while you are installing. After installation our floor was solid and it does seem to have a sound dampening property because it is noticeably quieter in our basement under this floor than previously.

Great product. Light weight, but strong. Perfect as an underlayment. Easy to cut/shape, thrn dropping LVP on top, it’s performed very well. Definitely will buy more in 2026.

I'm just going to start out by saying that I am a DIYer, not a professional of any kind! Ioriginally purchased this from Lowes in the 6mm thickness, and have installed it in 2 bedrooms and a hallway so far. I find it very easy to install and it works really well over my slightly uneven floors (my house is 91 years old so there's only so much that can be done!). It does make a lot of green dust when you cut it and walk on it, and I really detest the way it feels on my feet, but once you install your flooring over top that isn't an issue anymore. I will definitely update this review if I run into any future problems! I needed one more package of this and decided to purchase from Amazon because I thought it would be faster. It probably was, but shipping did not do my underlayment any favors. The box was partially open, and I'm not sure if it was just damaged in shipping or if they sort of wrapped the package in cardboard and sent her out. Anyways, the plastic covering the underlayment was torn open, the ends are all chipped off and the box was basically falling apart when I received it. It's usable, but I will definitely not be purchasing this from Amazon when I get around to redoing my downstairs office.

It is hard to write a complete review of this product because I am in an upstairs condo unit and can't really say how the neighbors below feel about the noise transmission. Let's just say that they have made no complaint. These pieces of underlayment are easy to put down (I have to confess that I didn't put them in at a 45 degree angle to the flooring). The first package gave us a lot of green dust, but later packets seemed not to. I suspect that the difference was that after box 1 (I used 8 boxes), I figured out that the best way to "cut" these pieces was by using a straightedge and scoring the piece with a chisel or screwdriver and then just folding on the scoring -- easier, cleaner and faster than using a blade. This product also had the highest Delta IIC rating I could find for an underlayment. The ratings for underlayment are very misleading. They show ratings for IIC and STC that are based on particular configurations of concrete and wood joist subfloors that may exist somewhere, but probably not in my 1980's condo. The Delta IIC, on the other hand, provides a rating that indicates how the underlayment performed in deadening impact noise when added to a subfloor. Thus it is a measure of how the product adds to a subfloor configuration. Maybe this isn't the best way to judge, but when 1/4" of cork has a Delta IIC of 24, you get a pretty good picture that perhaps this 3mm with a Delta IIC of 25 is the real deal for sound deadening. I had used some roll foam underlayment in two closets and it was a pain in the butt to roll out and get to lie down. These lie flat from the get go and it was much easier to lay down.

I put STEICO wood fiber underlayment (6mm) under my new hardwood floors, and honestly, I’m super happy with it. It’s all natural—no plastic or weird chemicals—which feels awesome for my place and the planet. Laying it down was a piece of cake; the sheets are easy to handle, and I just sliced them with a utility knife to fit. It’s crazy how quiet everything is now—footsteps don’t echo, and the whole room feels chill. Plus, it handled some uneven spots on my subfloor like a champ, and the floor’s rock-solid—no creaks or bouncy vibes. A few months in, it’s still perfect. If you want something green that actually works, STEICO’s legit!

This is easy to work with. Simply lay down and I like to tape them together, but it is not required. The product is soft and breaks easily, so you just have to work with it carefully. My base boards were so high that i needed to raise my new flooring by 1/4 inch. This did it perfectly.