I have a 10 x 12 room with concrete floor I am putting a click and lock floor on. There are some low spots along both walls totaling maybe 25 square feet and at most maybe 1/4 inch from being flat.

The guy at Lowes sold me Mapei Novoplan2. Does it need a primer (I think instruction say recommended but not clear over what). The floor looks in good clean shape.

Should the floor be slightly damp like with an atomizer or wetted with a sponge or rag before applying the SLC ?

And should I not be fiddling with SLC but just patching the low spots with Mapei Planipatch or something else ? I've heard the SLC sets up real quick and is not good for rookies who expect its really going to level itself without any troweling or smoothing. I just have a trowel but no long-handled squeegie looking spreader/smoother.

I really don't want the mess of just wet grinding high spots.

Thanks for any advice.

Bob

Bob, you called yourself a rookie . I don't believe we are allowed to use rookie and SLC in the same sentence . You might get it right or you could create a big mess.

I'm taking down the high spots and filling in with Planipatch or something similar.

The real rookie says "What is SLC?"

Airport code for Salt Lake City?

Bob, the problem with using SaltLakeCity airport codes to flatten concrete is the slab may or may not be level, which is totally different from the flatness issue.

You may have to build up alot more than you were expecting if you want to pour and self level. Also the doorways will need to be dammed, I think in most cases SLC's are not needed for a 10 x 12 room.

Planipatch set up just as quick, if not quicker, so you have to move fast with it.

Well I went ahead and used SLC (before I had seen last post). Don't know if I blew it or not but really learned alot. Biggest glitch is I discovered to my horror after dumping stuff on the floor that there were lumps. Had no alternative but to use it and when I'd come to a lump try to mash it and mix on the floor quickly with a trowel. I also may have blown it since I didn't cover the marked high spots (two two foot wide channes running the length of the room). Even though directions said to use enough material to cover high spots I was running out of material (used two 50 lb bags plus two bottles of primer- this stuff gets expensive !). I feathered it where it contacted the high spots so I hope I'm okay.

It did bring up the low spots and self-leveled pretty well, but I will see how well when I put a level to it tonight.

Two questions remain and instructions are silent with the product. I used Mapei's Novaplan 2. The questions are:

1) Can you come back and lay some more Novaplan 2 over the existing cured Novaplan 2 ? Or can you use some other material to smooth out some parts ?

2) Can you smooth out some feathered edges with a grinder, cinder block as a sanding block, or some other material ? When the second batch was spreading out, it was a little too viscous and didn't "self level" as much , so there are some edges that are raised.

Thanks for all your help. I'm going to go ahead and lay the floor this weekend.

Bob

I see a Fein Multimaster in his future! The carbide attachment sands right through thinset.

Forgot to tell you that you need a 1/2" low speed drill with a baffler mixer to get the lumps out. I don't know anything about Novaplan 2.

Normally I can use a 5" or 8" razor scraper (laid down almost flat)and shave the raised edges down pretty smooth.

I actually used a 1/2 inch drill with mixer. But you couldn't see the lumps in the bucket until they made it to the floor. And I'm a little miffed (at Lowes) because the first batch was fine, but the second bag had been around for awhile at Lowes or opened causing the lumps. I could have felt them possibly if I had felt the bag or stuck my hand in the powder when I opened it, but had no reason to. Besides I was a one-armed paper hanger at that point doing the job by myself and feared stuff would start setting up so I couldn't stop to go back to the mixing operation after pouring some of it on the floor.

BTW, great tip about using the razor scraper. I've got one and wasn't real thrilled with renting a wet grinder and didn't want to create a bunch of dust. I'm sure the scraper will work (and its a relatively small area). So, THANKS for the tip.

Bob

I meant to say a jiffler mixer..... I don't where I got baffler from... I'll be ok

Jerry,
Good ! Thanks. I was baffled by your reply.

Bob