The Maple Floor Fiasco

We found about 500sq.ft. of 5 inch wide maple plank flooring in a dumpster. It had a very slight warp to it due to it not being installed correctly. But with a little sanding we could get rid of that.

So we happily installed the flooring.



This pic shows the layers. First Pex tubes in sand/structolite mix with stringers 16" on center. Then some paper. Then the wood nailed into the stringers.

Despite our good intentions there were complications….
1. Maple is not a good choice for radiant floor heating since maple bows, warps, expands and contracts more than other woods when there are humidity swings.

2. Wide plank flooring is not good when there are humidity swings because it expands and contracts more than narrow planks.

We had wide planks. We had maple. We had radiant floor heating.

Then we had just laid the sand/structolite mix around the tubes. And my ex-carpenter didn’t give the mix enough time to dry before putting the wood down.

And my ex-carpenter nailed the planks in as if they were narrow plank oak over a normal floor, that is to say he nailed the floor down WAY too tightly. Wide plank, maple, radiant, these are all reasons to lay the wood down with some space between them so they can move.

And sure enough the wood warped immediately. I fired my carpenter.

With my new carpenter we have taken the wood up….yes these free planks of wood, valued at around $3500 for that many square feet, are no longer free. But no worries. We are still way ahead of the game.

The new plan is.

1. dry the wood out.


2. Let the floor dry out.

3. Seal the wood on all sides so that it doesn’t absorb water as well.

4. Before laying the wood we will put a real vapor barrier on the floor.

5. Then if all goes well we will just have to sand out the original bow and have a great, salvaged, affordable floor!

About the author: Gennaro Brooks-Church

4 comments to “The Maple Floor Fiasco”

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  1. Gennaro Brooks-Church - June 10, 2010 at 6:42 am

    I would not repeat the way I installed the flooring. But I knew going into it that I was taking a risk in the name of exploration.

    But the floors do work fine.

    The maple has pretty much become unglued from the low voc water based glue we used. Water based glue just doesn’t have any real strength. So now it is a floating floor. It feels a little softer than a floor that is attached solidly to the sub-floor but it does not feel bad.

    The floating floor allows it to expand and contract without any issues.

    The sand/concrete/structolite mix does help spread the heat out more evenly.

    Last winter the water was set at 120 F, which is high but not terrible. This winter we will have installed our new energy efficient doors and fixed our windows so I suspect we will be able to get the water temperature down to 100 F.

    So altogether the floor is fine. I think next time I would not do the concrete mix. I would build my own warmboard out of plywood and aluminium like we experimented in the upper floor. That one works great.

  2. Evan S - June 9, 2010 at 9:28 pm

    There are lots of comments / recommendations about installing maple flooring, yet very little data given.

    One comment I’ve read is that the nails should be 6 to 8″ apart. Given your 16″ spaced stringers, you may always have problems with wood movement.

    Also, at the Radiant Panel Association, they discuss the ability of media to transmit heat. Sand (by itself) is not a good media to transmit heat through for flooring. I did a search on structolite to see what it was and the USG description says that it is a good insulator. I take that to mean that you will have to have very high water temperatures to get sufficient heat out of the floor.

    Good luck.

  3. Gennaro Brooks-Church - June 29, 2009 at 7:53 pm

    thanks for the comment. i thought of that but we’ve decided to just lay them and then sand.

  4. mike pickett - June 29, 2009 at 7:48 pm

    buy a table planer they run about $400 and plane 1/16 off both sides if ness. just look at the bow and you’ll figure it out

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