The additive is something you add to the mix instead of water. It makes the filler bond to the vinyl flooring much better then plain water. That concoction is generally used to fill in grout lines in embossed vinyl flooring. The additive mixture can also be used as a final coat on a situation like you have. Mixed that way, it's designed as a skim coat. Skim coats are not applied heavy. It's a thin slurry that can easily be troweled really thin. When used an a vinyl embossing leveler, you can still see some of the vinyl flooring color through it. Skim coating on a new plywood floor isn't much thicker than that. It's a skim coat, and there's no reason to apply it thick unless you have issues with heights between two or more surfaces. I'm speaking of ramping a transition from 3/4 inch to 1/2 inch.
Now if all that flooring was relatively flat to start with, you would only want a thin skim coat barely covers the plywood. You'd just be filling in nail or screw holes and blending minor differences where plywood seams meet.
Long story short........ if all the plywood in the bathroom was the same thickness and there were no major issues with height differences between any of those panels, then you shouldn't have built up 1/8 of an inch of floor patch anywhere. I can't see from the photos if there are any height differences between sheets of plywood.
OK, the lump problems. I got lumps today in two bags of Ardex Feather finish. No big deal because it was leveling out a transition in an addition to the upstairs of a house. Covered with pad and carpet, I needed a flat surface, not a pretty surface like required for vinyl flooring.
I paid $10 for three 25# bags of another brand of a similar patch. That was an 80% savings. Cheap because the bags were "stiff" Lots of lumps in the bags because they were old.
I dropped the bags on the floor hard to shake them a bit. Once home, I cut the bags open one at a time. I sifted the filler into 5 gallon buckets using some fine window screen material. The lumps stayed above the screen and were thrown away. The fine powder that easily sifted through was saved in heavy duty garbage bags so moisture couldn't get to them. That stuff mixed up smoother than any filler I ever used. Zero lumps. I used that old filler for non important jobs or mixed it 50/50 with new bags of filler. Love to make a score like that again.
Now if all that flooring was relatively flat to start with, you would only want a thin skim coat barely covers the plywood. You'd just be filling in nail or screw holes and blending minor differences where plywood seams meet.
Long story short........ if all the plywood in the bathroom was the same thickness and there were no major issues with height differences between any of those panels, then you shouldn't have built up 1/8 of an inch of floor patch anywhere. I can't see from the photos if there are any height differences between sheets of plywood.
OK, the lump problems. I got lumps today in two bags of Ardex Feather finish. No big deal because it was leveling out a transition in an addition to the upstairs of a house. Covered with pad and carpet, I needed a flat surface, not a pretty surface like required for vinyl flooring.
I paid $10 for three 25# bags of another brand of a similar patch. That was an 80% savings. Cheap because the bags were "stiff" Lots of lumps in the bags because they were old.
I dropped the bags on the floor hard to shake them a bit. Once home, I cut the bags open one at a time. I sifted the filler into 5 gallon buckets using some fine window screen material. The lumps stayed above the screen and were thrown away. The fine powder that easily sifted through was saved in heavy duty garbage bags so moisture couldn't get to them. That stuff mixed up smoother than any filler I ever used. Zero lumps. I used that old filler for non important jobs or mixed it 50/50 with new bags of filler. Love to make a score like that again.
