Self Level Concrete Efficiently| SLU | Laticrete NXT Level | Level quick for large format tile

The official term is Flowable Hydraulic Cement Underlayment.
Page 94 TCNA Method F205 2023.

Using self levelers or Flow-able mortars on concrete can be tricky for newbies. Self levelers can be used to level floors, but in this video it is used to increase the overall flatness. The tile industry is working to replace the name self leveling underlayment with a more appropriate term. Currently the term self leveling implies that the product does all the work to make the substrate level. With enough of this product you could level the floor, but for most residential applications a flat floor is what is really needed, a level floor would be a bonus. Leveling a floor requires more knowledge than is shared in this video. This video demonstrates how to flatten a floor to meet the TCNA guidelines for floor flatness for Large Format Tile, which is 1/8th of an inch in 10'. See page 33 of the TCNA Handbook 2023-Substrate Tolerances for Thin-Bed Methods.

The main thing to make the process work and not create a nightmare is to have adequate preparation. If you have never worked with this type of material before, you better start small. Anything larger than a bedroom for a first time can easily go wrong. While this is very easy for Trendsetter and we do make it look that way, there is a learning curve.
We have done 2000 sq ft in a morning using exactly the same process seen here for this bedroom. The only difference being we used 3 bags per batch instead of 2. So doing large areas is not a problem using this procedure.

Installers sometimes ask me where to start when pouring. If the deviations in flatness are not too extreme I will typically start at the furthest point from the entry/exit of a given area. I do however add the SLU to a high spot as opposed to a low. I do this because it is easier to drag the SLU with the rake into a low spot rather than pull it out of the low. After you rake away from the high spot any excess SLU on the high will flow into the low anyway. Whereas if I drag it out of the low towards the high spot I may find the SLU lagging in coverage so to speak, and it may give me a false reading on how well I am placing since some of the material will again flow back to the low. This is not a rule, or a technique I was taught, it is just a way I found to be somewhat more efficient in most instances.

The majority of self levelers on the market use the same process to apply their product. We use NXT the most because it is very consistent. From bag to bag the product is predictable, where as with some products we have seen differences in color, or product strength from bag to bag, even though the mixing procedure was performed per the manufacturer's directions.


When going over plywood substrates the process is the same if you use NXT Level Plus. The Plus version does not require lath on plywood.