I'm in the process of a basement renovation including the install of an Armstrong laminate floor ( Pacific Heights antique hickory, a product that measures 51"x 3.31"x 8mm thick). The basement is dry, and after 12 years of residence, have never had an episode of water intrusion, so I'm confident that moisture will not be an issue. The concrete floor, while in good shape, had a tile floor on it that was removed by the previous owner prior to our purchase. There were areas that had residual cutback adhesive that have since been removed down to the surface of the concrete. After doing some homework, I decided to use Henry 547 Unipro underlayment ( available @ Home Depot & Lowes ) to cover the cutback and patch & smooth the floor.
I liked the fact that I could apply this product in layers and did not have to do the whole floor at once, like with a self leveling product. The floor is not level, but I have been able to bring most of the floor up to a degree of flatness that is close to the manufacturer's specs for subfloor prep (3/16" in 10ft or 1/8" in 6") I've found this stuff to adhere tenaciously to the concrete and cutback residue . I have used a notched trowel for the initial applications per the instructions. However, after some practice in other areas in my basement, following the techniques that I've used in the room under renovation, I have found the product difficult to get real smooth. The ridges left behind when using a large smooth trowel can be removed easily with a medium size putty knife, but despite a lot of practice and effort, the cratering and small voids left behind leave the surface un-even. I mix each batch as accuratly as I can, and I know that the strength of the product will be compromised if I try to cheat and thin out the material with too much water. I have come to realize that I can probably never get the final finish beyond the level of a decent skimcoat rather than a smooth, flat , featheredge with this product.
So I submit the following questions for your review:
1) Have I reached the limitations of surface quality with this product, or is there something else I can improve on regarding application and or finishing?
2) Is there another product that I could apply over Henry 547 that would bring the surface up to an acceptable level of smoothness? Would I have to use a self leveling product? How smooth does the subfloor really have to be for the laminate product that I bought? Would a product like Ardex Feather Finish be an alternative for the final finish coat, or should I stick with the 547?
3) I am also planning on building a bar as part of our renovation, and fastening the frame to the concrete with tapcon screws. There is no 547 material on this part of the floor yet. Should I fasten the frame to the concrete before, or after application of 547?
Many thanks to all in advance for your help and advice!!