"Sonny" wrote:

We have two large exterior exposed cypress beams/posts, that are part
of the structural wall and roof support of a breakfast nook area (back
patio area) that have developed rotted bottoms. I've been putting
off this repair because I'm not sure, exactly, what might be the
best/proper repair. Obviously, moisture has wicked up the posts for
some time, and the bottoms are rotten.
Left and right side posts, scroll left:
https://www.flickr.com/photos/43836144@N04/16411478004/

We've started demolition of part of the back patio, for the
construction of a pergola, spanning this breakfast nook wall area.
I need to repair these posts, soon. I'm not sure how far/deep, into
the wall, the rot goes, but I suspect maybe half way through the cross
section of the post. I'll probe it, later. Before I probe (gouge
out, cut into) the post, I would like to know what possibly might be
best for the repair..... I wouldn't want to have removed something, if
it could be part & party to the repair.

It would be very difficult to remove and replace the beam, since they
are part of the support structure, but if need be, that will be done.
I'd prefer to repair at least the bottom, for now, unless sunsequent
discovery of very extensive damaged is found. There is no plinth
under these beams.

I had thought of epoxy, since I more recently learned some of the
virtues of epoxy use; I've thought of bondo; THought of
patch-replacing parts of the beam.

I've thought of the wood hardening products, for rotted wood, like
this one:
http://www.pcepoxy.com/our-products/...terminator.php
Home depot, Lowes and other outlets have similar wood hardening
products, but I don't know anything about these products and I'm not
sure which brand/product is the best for this kind of structural
support, weight bearing use.

I'd appreciate any and all input, for this repair.

We have other posts on an side porch, that are supported on plinths,
that have bottom rot, also. These posts can be easily replaced, but
I'd prefer, for now, to repair the bottoms. They are stained with a
paint-like stain, so bondo may be an option for repairing/filling
voids, if need be. The porch roofing is cantelevered, but the posts
do supply some support for the porch, because of heavy tiles (1500
lbs/square) on the roof. Any advice would be appreciated for this
repair, also. Scroll left for another pic.
https://www.flickr.com/photos/438361...n/photostream/
----------------------------------------------
You are between a rock and a hard place.

First things first.

Bondo is a polyester based putty thickened with talc.

It's about as useful as a set of breasts on a boar hog.

It has limited adhesive properties. (Ever wonder why body repair
people
punch holes, then putty the holes over with Bondo?)

Products like git-rot, rot-doctor, etc, have been around for ever.

They are basically very low viscosity epoxy injected into rotted
wood to create a rotted wood core stabilized with epoxy.

Good structural results are at best mediocre.

Plinth construction is about the only way out if you want to sleep at
night.

Good luck

Lew