The Rot Doctor


Subject: floor board rot/termite damage
Date: Fri, 12 Mar 1999

Dr. Rot:

While in the process of replacing a patio door I noticed that the floor boards adjacent to the door have been rotted out and that subterranean termites are present, the boards are wet/moist due to rain water leaking underneath the old door's sill.

In this house, the 2x6 tongue and groove floor boards sit directly on the mudsill, there are no joists, just girders and floor boards. The floor boards near the patio door are rotted in about 3 to 4 inches, and the sill is 6" in width, (the redwood sill is in very good condition) so all of the boards still have solid wood-to-sill contact, although I'm not sure how far the termites have gone in.

Is an epoxy or filler available that will restore the structural strength of the rotted floor boards available? (the wood will be dry and the water problem fixed, termite source removed) . How do your products compare to the Minwax hardener/filler combo available at a local hardware store.


jim l.


Our CPES penetrating epoxy followed by some Fill-It epoxy putty are exactly what you need. Since you didn't notice the rotten boards until you repaired the door sill, I am assuming that the rot is not visible from the surface of the floor. Generally we recommend drilling access holes 4-6 inches past the last visible part of the rot and flooding the CPES into the area of rot from there, (in addition to from the rotted area) but you probably want to maintain the look of your floorboards (no holes). Flooding the CPES from the rotten ends should be sufficient to penetrate all the rotten wood, checking the rot and restoring strength to the wood (epoxy is very strong). Just be sure to give the wood all the CPES that it will take. I would do two applications to be sure. After they cure, you can follow with Fill-It epoxy putty to fill any voids. It is a white putty, but your holes should be out of sight. This will restore more than enough strength, equal or greater than the original wood.

We have tested the Minwax product (as well as all others that we can get our hands on) and have found it to be a vastly inferior product. Our CPES penetrates roughly 10 times farther, and is much stronger than the acrylic that Minwax uses. Our testing has yet to find a product that is even close to ours in performance.

Please let me know if I can answer any further questions.