What is “flat and smooth”?

Two of the most common words we use when describing an upcoming flooring job are “flat and smooth”.  But what exactly does “flat and smooth” mean?

The foremost rule of thumb when it comes to installed flooring is that whatever you start with is what you finish with – and that goes double for your subfloor prep work!  Whenever it’s time to install a new floor into a space, the subfloor (that is, the unfinished flooring substrate underneath the new flooring surface you see and walk on) needs to be made as flat, even, and absolutely smooth as possible.  This subfloor won’t ever be seen directly, but any dirt, sand, debris, or holes will ‘telegraph’ right through the new finished flooring in no time flat.

We received a call from a new client who was experiencing ‘telegraphing’ problems through the their cafeteria’s sheet vinyl floor.  The floor itself was only a fraction of the way through its working lifespan, but it needed full replacement due to improper prep work during its original installation.

• The original installers hadn’t applied a skim coating to the basic concrete subfloor.  Instead of flat and smooth, they started out with rough and bumpy!
• To save time and dollars, they filled-in and patched holes in the concrete with adhesive instead of skim coat. That’s not how flooring adhesive is meant to be used, so over time those patches contracted and shrank, reopening those holes in the concrete.
• As the adhesive holding the client’s floor in place aged, it began to show every pit and hole in the concrete subfloor beneath!

As part of a professional re-installation, we completely removed the old flooring and all the excess adhesive used to patch up the holes and pits in the concrete subfloor, and completed a mild grinding to get a level, flat surface.  We then applied a skim coat of finishing concrete for a perfectly flat and smooth subfloor, and installed a new sheet vinyl floor using adhesive via the manufacturer’s approved methods.

In the long run, the cost-saving shortcuts taken by the original installer ended up costing the client more!  The client had to replace their floor prematurely, and the extra prep work required to undo the previous poor installation also added to the cost.  But now the client has a beautiful new cafeteria floor installed properly that will last for years and years to come!