Repairing minor wood rot on foundation beams?

[Pat Barry]

I have a northern MN cabin that I am working on. Last weekend I removed soil that has, over a number of years built up along side the foundation which is timber beams on concrete pillars. The lowest piece of half half log siding was in concact with the ground and had significant rot so I removed it. Under that, the foundation beam was also in contact with the ground and had been for quite a while. I removed the dirt a few inches below the beam and inspected / tested it for rot. Thankfully it looked pretty solid but had some rot that didn't seem to penetrate very deep. MY question is how to repair / treat this. I found a product (http://www.homedepot.com/p/PC-Products-24-oz-PC-Rot-Terminator-240618/100649635) sold by HD that looks like a possibility I would need it to wick up into the beam from the bottom.

What I'm thinking is that I would apply this product liberally to the beam and let it soak in as best it can. Once dry I would fit in some tarpaper, under the next course up of half log siding and overlapping the beam. Then I would install an aluminum drip shield under the last course and finally lag bolt a green treated 2x12 to the beam over the tarp paper from the outside tucked under the drip shield. This way I could backfill some rock and dirt up against the 2x12 and seal off the foundation.

Does anyone have experience with the rot repair epoxy product? Does it work? Any advice on how to use it?

What do you guys think of the repair overall? Would you do things differently?

[Phil Thien]

Having a hard time picturing your repair, but I will tell you that sistering anything to the existing beam is a recipe for rot.

Have any pics?

[Pat Barry]

Having a hard time picturing your repair, but I will tell you that sistering anything to the existing beam is a recipe for rot.
Have any pics?
I made a quick sketch - hope this helps to clarify what I was thinking
293926

The dark grey is the earth / dirt
The light grey are the concrete posts / foundation
The tan horizontal member is the beam - it is rotting from underneath and the bottom of the exposed face as you see it - not sure what is going on behind it because I can't get to it.
The yellow horizontal pieces are the half log siding.

So what I want to do is paint on - very liberally - the rot preventer epoxy mix and have it soak into the log beam.
Once that is dry I was thinking to fit the tar paper under the last (bottom row of the log siding to help keep water running down off the siding getting onto the beam. Then, over the tar paper and under the bottom of the siding put in a sheet metal drip edgeso it directs any water awya from the beam /tar paper.
Then, to face cover the beam and protect it further, and maybe add back some structure, lag bolt on the 2x12 (shown in olive green).

The log is sitting on the concrete post without any separation and I don't think I can correct that so I think the best thing is to keep the beam as dry as possible and protect it as best I can. The building has stood for about 50 years as is but I do think the rot is a relatively recent.

If this doesn't help I'll try to improve my sketch. I don't have a picture, sorry - I should have taken a picture or two last weekend. Now I won't get back for a few days.

The earth itself is very fine sandy soil - not clay, not gravel, not black dirt so it drains water away very well.

[Lloyd McKinlay]

Take a look at Liquid Wood from Abatron. It restores some structural integrity.

[Tom M King]

First, do what you need to for it to dry out. It might take six months, once you get it so air circulates around it. There are many possibilities. Pictures would help. I've even repaired some sills with concrete that still had plenty of good structural wood left, but those were rotten into the top. Bugs may be in it too, and that will have to be dealt with. The main thing is a good design to keep them dry from now on, and it sounds like you are working on that. It's not unusual for me to go through a 5 gallon thing of West Systems working on an old house on such things as this.

[Andrew Pitonyak]

Disclaimer: I am not an expert in these things, but, I have recently done reading on this topic.

Boat Builders seem to like Smith's CPES (see http://www.smithandcompany.org/CPES/)

I have no particular reason to know that Smith's is any better than the product that you mentioned.

Smith's recommend that you read the documents at this site on restoring rotten wood with a penetrating epoxy

http://www.woodrestoration.com/

Penetrating sealers will not penetrate paint. Also, if the wood is waterlogged, it will not penetrate. Smith claims that his product will dissolve SOME water, but, if you have something that is water repellent you will not likely have much luck.

How deep is the rot? The penetrating epoxy must be able to get through all the troubled area. Wood with some rot soaks up the sealer better than straight wood, but, you need to make sure that you can keep sufficient sealer on there that it has time to penetrate. If you do not penetrate past the rot, then it may continue to rot from behind. You must be able to obtain sufficient penetration. They did not have good luck penetrating paper in this test (http://www.ewoodcare.com/Epoxy%20Penetration%20Test.pdf), but, rotten wood is much better at soaking up liquid (I have seen finish penetrate through 1" thick wood, if I remember correctly it was African Mahogany) .

You probably want to apply multiple coats. Two may suffice, but, as long as you can get it to soak up the sealer, you want to keep applying the sealer. You do this for the first coat (apply what it can absorb). You do it again for the second coat, etc.

I assume that the sealer product will affect the structural integrity (probably improves it), but, if the integrity is already compromised from the rot, do not expect this to magically take rotten wood from not strong enough to be strong enough for any particular application.

If you can, attempt to determine how deep the root penetrates. You may be able to use something like an ice pick or even a small drill bit to determine this. Just remember though that any hole then allows other things to penetrate. Speaking of that, for some applications, they even recommend drilling some holes to allow the penetrating epoxy better access to the interior.

Lots of good information here:
http://www.rotdoctor.com/house/Houtdoor.html

Finally, a penetrating epoxy is not the be-all end-all product. I think that they generally recommend that you provide another coat of something on top of it.

[Tom M King]

If the rotted portion leaves enough other wood, if it was removed, to be still plenty substantial for its purpose, it might not be necessary to do anything to the beam, other than letting it dry out, dig out the rotten part, and make provisions for it to stay dry from now on.

[Mark W Pugh]

I have some floor joists on my outside deck that needs work. This is what I'm going to attempt. From what I have read, you need to stop the rot, or at least cut ALL of it out.

http://www.systemthree.com/store/pc/Rot-Repair-c33.htm

It is a free standing deck, so I thought this would be the best way to go. This product may not be the way you need to go.

[Mark Wooden]

I've gotten very good results with Flex-Tec

http://www.advancedrepair.com/architectural_epoxy_flex_tec_hv_info_instructions. html

[Phil Thien]

The pic helps a lot.

So your plan is sound PROVIDED you can keep water off the top of the 2x12, so it can't penetrate between the beam and the 2x12 (that will result in very rapid decay).

What is behind the half-log siding?

[Tom M King]

How is the log siding held on?