Can my floor be sanded?

Flooring Technology

That’s a question that we get a lot.  Most often, a professional inspection is necessary, and even then, it can be hard to tell sometimes.  We tend to err on the side of caution, but there are certain things to look for that can help in that determination.

How to tell what you have:
The easiest place to see is inside a floor vent.  Here, you can determine the overall thickness of your floor, and (in that particular place), see the wear surface between the top surface of the board and the tongue and groove (in the case of engineered flooring (real top layer, multiple layer plywood construction), the thickness of the wood in the “real” layer).

If you do not have floor vents, but have base vents, you may be able to check the material thickness there, but may want to have a flashlight and maybe even a mirror handy.

If you don’t have either of those options, you may need to pull some trim to see the side profile of the material.

Solid, 3/4? floors:
Most 3/4? solid floors have plenty of wear surface, but there can be exceptions:
  • Very old homes, where the floors may have been sanded many times.
  • Water damage, were the flooring is warped in significant areas.
  • Floors that have been sanded by a non-professional

    Solid, 3/8? floors:
    These can be tricky.  They start out with very thin wear surfaces, which can only be sanded professionally a couple of times.  Since these types of floors tend to be only installed in older homes, the odds are greater that they have been sanded multiple times.  Additionally, any water damage that curls the edges of this material tend to make a successful sanding unlikely.

    Engineered wood floors:
    The key to the sand-ability of an engineered floor is the top layer.  Most engineered floors have very thin wear layers.  Some cannot be sanded at all.  Some may have one sanding in them.  A select few will have a very nice wear surface ( 3 to 4 mm).  Since engineered floors have opposing layers, and the layers underneath the top layer are most often a different species of wood,  even a slight sand-through of the wear surface will be extremely noticeable.

    A visual inspection of the floor:
    Once we’ve noted exactly what we are dealing with, we will do a visual inspection of the field of the floor itself.  There are a few warning signs that the wood floor has come to end of its wear layer:

  • Exposed nail heads in the seams between boards.
  • The top sides of the edge peeling off in spots.
  • Cracked boards, especially near the edge.

    Since most floors are fastened at a 45 degree angle through the tongue of the board, an exposed nail or staple spells trouble.  Many times, especially in 3/8? material, these are exposed when the wear layer gets too thin, and since they are the only thing holding down the board, they cannot be set. These same things can sometimes be seen in a heavily sanded 3/4? floor too.

    If the floor has nearly been sanded through it’s wear surface, we often see the edge above the groove either peeling up or cracking, as that area has gotten so thin that it cannot withstand walking traffic and general movement that a floor undergoes.

    Another key factor we consider is whether the floor has been sanded by a non-professional.  A professional sanding will only take off a very thin layer of wear surface.  However, sanding equipment can be very, very aggressive, and in the hands of a do-it-yourselfer, very deep marks can be left in the surface of the flooring.

    The final determination:
    After all the above factors have been inspected, noted and weighted, the advisability of sanding can be determined (to a degree).  I say “to a degree”, because floors can be sanded unevenly.  There may be spots which weren’t very flat in the initial install, and were sanded flat, making it possible that some spots in the floor have less wear surface than others.

    If the available wear surface is limited, or some of the warning signs of thin wear surface are present, it is probably better to remove the floor and install a new one.  As always, we give free estimates, and would be happy to advise you on what to do with your floor, or even on a floor in a home that you are considering for purchase.