The Rot Doctor


Subject: DRY ROT
Date: 18 Feb 2000

I am restoring a 1754 cape, and have found dry rot in the beams that surround the center chimney. I have added support under the beams and would like to avoid replacing them as it would require re-fitting the floor joists. The rot appears to be up to 1.5" deep and only on the lowest portion of the beams. The beams are approx. 10" X 10" X 12' long. Is this repair feasible? How much material would be required? If needed, I can send photos.

Howard B.


Photos are always helpful, if you can manage it. If by e-mail, send in jpg or gif format.

To answer your question directly, yes, you can use our products to restore solidity to the wood and reduce the chances of any future rot to a very high degree. You would use CPES (Clear Penetrating Epoxy Sealer) and, if the wood is badly deteriorated, followed by our Layup & Laminating Resin. The restoration with a deep penetrating epoxy will give the treated wood substantial compressive strength.

We would also suggest that you coat the entire beam with CPES, because the rot fungi usually exist (or their reproductive spores) outside the area of visible rot. Applied to good wood, where absorption is not so great, it doesn't take much CPES to complete the treatment.

Based on our testing, 1.5" is right on the margin of how far CPES will wick upwards if applied to a lower surface. You, of course, would be applying it to the sides as well. I would say that if by probing you find that 1.5" is about the deepest the rot penetrates the beams, then a surface application of CPES (allowing the wood to absorb all that it can) would be sufficient. If you suspect that there are areas where the rot may be deeper, we'd suggest drilling some slightly downward sloping holes in the sides of the beams and injecting the CPES into the holes to guarantee internal saturation. CPES is a very thin liquid (about like diesel fuel) and will penetrate a long way through soft wood.

Tell me how many beams you have and I can give you an estimate of how much CPES would be required for treatment. Tell me also how bad the rot is and I can give you an opinion as to whether the Layup & Laminating Resin will be required. Or perhaps I'll be able to see that in the pictures.