i have leveled out my floor with SLC and put backer board over top, found center of my room and dry laid my tiles...now my problem is im having some tiles(13x13" tiles) not sit level or flat(which tells me the floor is not perfectly level or flat)...some seem to be out about 1/8" and rock from corner to corner(if that makes sense)...will this issue be solved with a thicker mortar bed in these spots? should i use a 3/8" trowel or stick with the 1/4"...many thanks for any help
An 1/8" hill over what length? The spec for substrate flatness when using basic tiles is: "Within 1/4" in 10 ft. and 1/16" in 12" of the required plane." Doesn't sound like you're ready for tiles yet.
Many people have trouble with SLC. They usually; Do not mix it right. Work too slow. Think it actually levels all by itself, cuz it's called "self-leveling". Do not have enough product on hand. Many times they need to do several pours.
You need to get a long straight edge and measure how out-of-plane it is. Let us know.
A 1/4x3/8x1/4 trowel is the basic one for your tiles. 1/4x1/4 is too small. You mentioned nothing about the subfloor, what is it?
TILE GUY - retired- TROY, MI - Method & Product suitability consulting.