Structural Beam Repair - Rotted Beam

We have two large exterior exposed cypress beams/posts, that are part of th e structural wall and roof support of a breakfast nook area (back patio are a) 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. Obvi ously, 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 the se posts, soon. I'm not sure how far/deep, into the wall, the rot goes, bu t I suspect maybe half way through the cross section of the post. I'll pr obe 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 p art of the support structure, but if need be, that will be done. I'd pref er to repair at least the bottom, for now, unless sunsequent discovery of v ery 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 o f 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/wood-repair/pc-rot-terminator.php Home depot, Lowes and other outlets have similar wood hardening products, b ut 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 h ave 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 por ch roofing is cantelevered, but the posts do supply some support for the po rch, because of heavy tiles (1500 lbs/square) on the roof. Any advice woul d be appreciated for this repair, also. Scroll left for another pic. https://www.flickr.com/photos/43836144@N04/16826710937/in/photostream/
Sonny
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wrote:

If you're not concerned about the current structural integrity and want to stop the deterioration where it is, try looking around <http://www.rotdoctor.com . I've used a number of these products with good results. It's not a wood replacement, though.

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"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/wood-repair/pc-rot-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/43836144@N04/16826710937/in/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
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wrote:

Support the structure with jack posts, Cut off rotted bottom 'till you reach solid wood. Build masonry posts/supports from ground up to wooden post. Prevent wood from directly contacting masonry so it cannot absorb moisture.(using moisture barrier of some sort - best to put wooden posts on metal (stainless or hot galvanized)saddles rather than directly on concrete - put trim around post to "hide" the saddle and cover the necessary gap.
DO NOT use "bondo". It is not structural, and polyester auto body filler is not waterproof - it acts like a sponge - particularly the normal talc-filled crap.
Epoxy is better, but filling rotten wood with epoxy still leaves you with rotten wood..
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says it sucks up water. I don't know how long I have used Bondo but it has been several decades and I have never found either of those negatives to be true.
I have a couple of bottom rotted, exterior door jambs that were repaired with Bondo at least ten years ago. Still good. As Lew said, Bondo is polyester resin filled with (mostly) talc. To my knowledge, cured polyester doesn't "suck up water" and talc is about the least liquid absorbing mineral around which is why it - in rock form - is/was the choice for chemlab work table tops.
There is no doubt in my mind that filled epoxy is better than Bondo. Nevertheless, for just a cosmetic repair, I would use Bondo...it can be set up and sandable in minutes vs the hours for epoxy.
--

dadiOH
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Actually, polyester is notorious for doing exactly that. Google for "polyester blistering" and you'll find 1000s of articles on the problem.
As for the original problem, I'd agree with those who suggest cutting off the affected part, and installing some sort of plinth. There's really no way to treat rot other than replacement.
John
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I've seen my share of blisters but the ones I have seen have been between layers of laminate or separation of the laminate from a surface.
I DAGS and the best page I found is relative to fiberglass/polyester resin on boats from the link below. I have copied and pasted some excerpts, CAPS are added to draw attention.
All said and done, I wouldn't worry about using Bondo as a rotted/missing wood repair :)
dadiOH ____________________________
http://www.hartoftmarinesurvey.com/guide.html Further observation shows that bottom laminate constructed with the commonly used orthophalic resins has a LIFE EXPECTANCY OF AROUND 30 TO 35 YEARS before deterioration due to blistering and resin damage has structurally weakened the bottom laminate. This deterioration can often be observed as flexing of the bottom laminate when hand pressure is applied even on boats in the 40' to 50' range.
Fiberglass blistering is caused by one or more factors such as resin type, contamination of materials, trapped gases, built-in voids, poor wetting out of laminate, incorrect humidity or temperature and dry layup. Osmotic fiberglass blistering is a process which depends on the temperature of, and exposure time to, the water. Given the above mentioned factors, it is not surprising that fiberglass blisters appear on a large number of vessels which are KEPT AFLOAT FOR LONG PERIODS OF TIME IN RELATIVELY WARM WATER.
FIBERGLASS BLISTERS FORM ONLY WHEN WATER PENETRATES TO THE LAMINATE. THIS WATER NOT ONLY DAMAGES THE LAMINATE BY FORMING BLISTERS CAUSING LOCALIZED DELAMINATION BUT ALSO COMBINES WITH UNCURED WATER SOLUBLE AND HYDROSCOPIC COMPONENTS IN THE RESIN FORMING AN ACID SOLUTION WHICH IS HIGHLY CORROSIVE TO EVEN THE WELL CURED POLYMERS IN THE RESIN. As more water reaches the laminate, more corrosive solution is formed and more resin broken down. The effect is that of flushing the resin out from between the fiberglass strands. A laminate so affected is often referred to as having been hydrolyzed.
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wrote:

That speaks to fiberglass laminates - not polyester body filler. Go to the Bondo web site. Mondo.com, and their TIPS page.
Quote: " Is body filler water resistant?
Yes. Water absorption tests show that filler only absorbs 0.3% of water,which is considered minimal. Therefore, body filler is not waterproof by itself but is water resistant. Note: If the application is primed and painted, the paint will render the application waterproof."
The fact that it needs to be primed and painted to make it waterproof, and generally the backside of a rustout repair in NOT primed and painted, meats water can still be absorbed into the filler from behind - and when that water entrenched in the polyester filler freases, it pops off of the metal, and out of the repair. It might not be a problem in Arizona - or alabama or florida - but it is a very real problem here in "the north".
There is a reason they also make a fiberglass filled body filler, which IS advertized as being "waterproof". If you look at their How to for rust repair they use "bondo-glass" for the initial repair to fill and seal the hole. This is their "waterproof" product. Then they have you finish the repair with "bondo body filler" which is the poyester body filler you guys are talking about. When fixing a dent their How To has you filling with "bondo body filler", preparing the bare metal surface with a 36 grit disc to allow the bondo to stick.
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In my first reply I asked Sonny if he wanted to make a strucrural or cosmetic repair. If structural, I said replacement or reinforcement. For cosmetic, I mentioned several ways including Bondo. For any filling of a cosmetic repair of rotted wood, one has to dig out the bad wood.
--

dadiOH
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Easily done.

NP
dadiOH
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wrote:

Just going from years of experience with body work and my late brother who was a bodyman half his life. A hole was always filled with either a brazed/welded/soldered metal patch or an epoxy/fiberglass patch before filling with polyester body filler if you wanted it to stay firmly attached long term. That's why Lew says it doesn't stick well. Also, it will not stick well to a perfectly smooth surface - you always rough up the patch area with 80 or 40 grit sand paper before applying bondo if you want it to stay stuck.It needs a mechanical "tooth" to stick well. (which is also why a "hack" bodyman will punch a dent full of holes to extrude the "bondo" into to give it a fighting chance of staying in. The newer "light" fillers that use glass microbeads instead of talc stand up better to moisture, and epoxy or UV Cure fillers are even better. When I hear "bondo" I think cheap polyester body filler - and I make sure it is well protected from moisture in use..
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I wouldn't waste my time with fillers or stabilizers. If you want it to last, replace the posts.
I can't tell for sure from the pictures, but the one that has the propane tank looks like the bottom of the post may have already been replaced at some point. About a foot from the bottom the grain doesn't line up.
The exposed posts would be fairly easy to replace. Just use a bottle jack and a shorter post to jack up the structure slightly. Don't go crazy jacking it up, you just want to take the load off the existing post. Then cut the old post out and install a new one. Ideally you should install a metal post base at the bottom of the post to prevent water from wicking up. Barring that, I would at least put some tar paper or sill sealer under the post as a water barrier. Not ideal, but better than nothing if you're not going to use a post base.
The ones that are inset into the structure are going to be a bit more work. You may have to cut the structure away from the posts, then jack up and replace. You will most likely need to repair wall surrounding the posts afterwards. I don't know how it's all put together but it may be easier just to take the wall down and rebuild it after replacing the posts.
Good luck,
Anthony Watson www.mountainsoftware.com www.watsondiy.com
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On 4/5/2015 10:50 AM, HerHusband wrote:

This, nuff said.
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On Sunday, April 5, 2015 at 11:36:25 AM UTC-5, Swingman wrote: , HerHusband wrote:

Yeah, I was hoping for an easy out, an easy fix, but I figured there was no ne.

ne

t

No previous repairs. It's all one continuous post, salvaged hand hewn beam s. Those misalignments are the result of the hewn marks, when squaring the beam.
I need to figure out how to seal the bottoms. I don't recall sealing the bottoms, when initially installed. We just treated the faces as best we c ould, once installed. It'll be major reconstruction to replace the beams. About the only part not attached to the other framing menbers is just insi de the exterior walls... we packed the uneven cracks with backer rods, rath er than using caulk. Maybe this spacing, though packed, was deficient, al lowing moisture to enter, but there is no evidence of moisture damage along the walls (that we can see), just at the bottom of the beams. No eveidenc e of moisture entrance on the inside of the room.
Thanks to all. Sonny
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Seal with thinned varnish, in two or three applications.
But more important is a way to block wicking, so that dampness in whatever the post rests upon cannot creep up the post over time. They make special cast aluminum post bottoms for this purpose. One can also make one from metal stock.
Joe Gwinn
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wrote:

Or even use an asphalt shingle.
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Sonny,

Interesting. Pictures can be misleading... :)

They sell brush on wood preservatives specifically for treating the ends of cut wood:
http://www.homedepot.com/p/Unbranded-1-qt-Copper-Green-Brown-Wood- Preservative-CB-QTS/202688831
Ideally, you should use a metal base under the post to elevate it off the ground (and secure it at the bottom):
http://www.homedepot.com/p/Simpson-Strong-Tie-ABA-6x6-ZMAX-Galvanized- Adjustable-Post-Base-ABA66Z/100375370
Barring that, anything you can use to separate the wood from concrete below. Plastic seal sealer or even a couple layers of tar paper.

Just for clarification: "posts" are the vertical structural members that hold up horizontal "beams".
You keep mentioning "beams" so I'm not sure if you are having other issues beyond the wicking at the bottom of the posts?

Unless you have wiring or something running through the posts, you can probably just use a reciprocating saw with a long blade to cut the nails between the wall and the posts. Then jack up the stucture above and slip out the posts.
I'm not sure what the best way to reattach the walls to the post would be during installation though. You would probably need to remove some of the interior wall covering to drive in some long screws or something.
Good luck,
Anthony Watson www.mountainsoftware.com www.watsondiy.com
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Lag bolt a stout block of wood to the posts in the wall so you have something to jack against with two bottle jacks and a stout cross piece to keet the jacks away from the work area. Cut away all rotten wood, make a plinth at least 1" above grade and scarf in new wood with at least an 8:1 joint using epoxy and lag bolts. Bed the foot on epoxy + glass cloth, or mastic + roofing felt to seal it. If the original post was in a hole, the new plinth needs locating pegs with corrisponding holes in the post bottom which should be strong and non-corroding. e.g. stainless or bronze allthread or thick GRP dowel. Assemble the scarf last so you can fit the new piece over the pegs onto the bedding The same will work for the other posts, but you dont need the jacking piece as you can jack against the roof beam and I'd through bolt the scarf.
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ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
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