protecting freshly cut logs
weekendwarriorben
| Posted in Construction Techniques on
One of our clients will be supporting a porch (custom Oregon ocean bluff home) with newly harvested logs (10-14″dia. hemlock). They were pulled out so that some of the main roots are still part of the log; the intend being to place them upside down so that the roots flare out basket style to receive the roof beams. We are looking for a treatment for these logs that minimizes (not prevents) checking, splitting, etc over time. I’ve heard of putting parafin or another wax-type product on the cut ends, for instance.
Should we leave the bark on as long as possible?
Replies
Nothing will prevent checking short of hollowing out the log. It is a result of the fact that logs shrink tangentially to the growth rings, but not as much radially (that is why vertical grain boards are more stable). The outer growth rings get shorter as they dry, but the diameter doesn't change enough to accommodate the shrinkage. So she splits.
I have heard of kerfing the log to make it split on a predictable path. I haven't tried it.
End checking is a different thing that happens because the end of the log dries out and shrinks before the middle part of the log. This can be prevented by coating it with any number of things (black jack roof cement works for one thing). However, you can also leave the log long until it is seasoned, and then trim it to length.
As to the bark, usually it's best to get it off or you risk sap stain, mold, etc. But that depends on the species. Again, checking is built into the structure of the log.
There are a number of commercially-available treatments for timbers to reduce checking. I'm not personally familiar with any of them, but here's one I found with Google: http://www.preservation-solutions.com/checksincheck.php
Checking out some sawmill equipment sites might lead you to others.
http://www.leevalley.com/wood/page.aspx?c=2&p=20079cat=1,190,42942
http://www.leevalley.com/wood/page.aspx?c=2&p=20080cat=1,190,42942
http://www.leevalley.com/wood/page.aspx?c=2&p=20099cat=1,190,42942
last one isn't available for shipment to US but it gives you somewhere to start. good luck. sounds like a cool project.
Those links don't work -- you've got to give the item numbers.
The mark of the immature man is that he wants to die nobly for a cause, while the mark of a mature man is that he wants to live humbly for one. --Wilhelm Stekel
Just go into a wood workers store and buy some end sealant.. lacking that coat the end with paint. Plan on trimming off about an inch of the end when dried and finally used. Wood air dries out approx. 1 inch per year so if these logs are 20 inches you've got a long wait. My 12"x12" timbers still haven't completely dired to their center and it's been more than 12 years since they were harvested..
Where are the logs going to be stored? Hemlock isn't particularly rot resistant, so if you're keeping them outdoors they should be rolled up onto some scrap lumber.
>>>Should we leave the bark on as long as possible?
I wouldn't, especially if the logs are stored outdoors. Critters love to get under the bark and you'll be left with lots of "character" from their burrows.
Don't worry about weathering once the bark is off. Some drawknife work, or oxalic acid, will have it shiny in no time.
Scott.
I worked on a house where the owner/builder used exposed Doug fir beams.
Every time he cut the end of a beam he sealed it with heated up wax.
He had a little pot on top of an electric cooker so the wax would be liquid.
It worked. All his beams were worked to the ninth degree. He had portable planer knives custom cut to put fake adz marks on the beams. Square pegs were pounded in at fake joinery.
After the beams were installed a mix of heated wax was applied that was darker.
And then they were buffed a bit. Needless to say they looked incredible.
The nice thing about the wax was it never really dried and you could always put more on. I'm pretty sure it was beeswax.
No checking. But these were kiln dried Doug fir #2 or better hand selected from the yard. West coast yard 20 years ago.
I worked on some of the more intricate beams.
With logs you will get checking. But the ends you can seal and lessen the end checking.
I'd strip everything off and seal them. Most people don't want to go through the work of treating big timbers like finished materials for so many steps.
Everybody on the job sight needs to know if you don't touch the beams. You can tell some people and they just won't hear it.
or if they are kept indoors you can simple shellac them..
If nothing else you are persistant. Not that there's anything wrong with that. ;^)
I like log cabin type furniture and finish work that has that brushed on finish.
Is that shellac? When I was a kid we would go up to a friends cabin and the whole interior was like that. All pine with the knots and the smell.
Probably not. Shellac loses it's odor quickly. If you can smell the wood it most definately isn't shellac because one of shellacs tricks is to completely cover up odor.
got a minute? <G>
That took more than a minute....now I'm off to bed and will put off till tomorrow iontroducing you to a new, exciting, (possibly/hopefully) lucrative farm/garden enterprise that could make me competitive with a Montana Chick-pea ranch.
Hey, thanks; i figured you'd be the go-to guy. I'd never heard of the borate pencils before. Learn something new every time i click on a link, i swear.... Chick-peas...thanks for reminding me! I'm slobbering all over my newly arrived Territorial Seed catalog; thanks for turning me on to that, too.
Google Impel rods and learn a lot more about how borates work to prevent the spread of wood destroying micro-organisms. Boracare is another product that is a liquid gel to mix down and spray on to get the borates on/in the wood asa surfacant.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Yeah, the principle is easy to understand, since borate is used in cellulose and foam insulation manufacture. I'd just never heard of it being put in/on logs since everyone i know uses copper solutions. I know a couple guys who work in log home manufacture here and i'll ask them if anyone around here uses these borates rods. Since they require moisture to activate, it could be we're just too dry of a climate to need them. Or...could be it's a good idea that just hasn't made it to the hinterlands, lol. I was all excited when Advantech came out...but i still haven't seen it here, years later.
Western Hemlock has both some virtues and some vices: If kept sheltered and out of wind and direct sunlight, it will check very little as it dries; it has little rot resistance but readily accepts any number of pesticide and fungicide treatments. (It's probably the most commonly used species for pressure treated wood here in the PNW.)
I do, on occasion, use logs in ways similar to what you're doing (though I usually use Doug Fir or Western Red Cedar) and prefer one of the Penofin penetrating oil stains for a sealer and finish. When the sapwood is reasonably dry it will soak up the Penofin product better than most other stains.
Hemlock, by nature, is a tree that carries a high volume of water in the living tree: Some years ago, I drove log trucks for awhile and occasionally I would deliver a load of Hemlock to a mill that cut only hemlock lumber. Many of the butt cuts (which you'll be using) were so water-laden that the log yard guys would strap 55 gallon drums to the logs before they went into the mill pond. So the drying time of your wood is going to take awhile.
So I would be sure to do one rot prevention treatment to the bottom end of your logs that I always do to mine regardless of species: Install "Impel Rods" which are Borate pencils that come in a variety of diameters and lengths; are inserted into bored holes above the base of your post (or in other places exposed to weather and likely to trap moisture).
They're manufactured by Wood Care Systems in Kirkland Washington, who can be reached at 1-800-827-3480 or http://www.Ewoodcare.com
They're available from a variety of vendors; I get mine through System Three in Seattle, but if you do a Google on Impel rods, you'll find some Oregon distributers.
I would not build any permanent exterior log structure without using them in critical areas.
And last, but not least, be sure to isolate the bottom of your posts from the base they sit on: I always seal the bottoms, place a piece of Ice and Water shield against the treated grain and make a steel post anchor with an isolation plate to keep the post off the masonry or concrete by a half-inch or more.
If you want more info, email me through the forum here.
One other option, and one I would highly recommend if your client is willing to spend a few extra bucks, is to have the logs pressure treated with the wolmanizing treatment.
I totally replaced all the log posts, beams, knee braces and drawknifed railings and balusters on a two story log home four years ago here on the Oregon coast.
While the log home walls were well protected by the large overhanging porches, the porch structure and stairways were exposed to the weather and had developed extensive decay, in large part because vulnerable notched areas and the post bases were not constructed with weather in mind.
I supplied all the primary post and beam logs and braces, while the client purchased new railing and baluster stock from the original supplier of the log home components.
The client shipped all the new log components to a treating plant in Portland, Oregon for Wolmanizing.
The nice thing about wolmanizing is that it's not only an effective treatment, but it leaves the wood with only a very light tan color
Once the porches were rebuilt, the logs were finished with a penetrating stain (I believe the customer used Sikkens) and the results were beautiful.
I did use impel rods in the bottom of the posts, in the knee brace notches and the post/beam connections.
I don't have the name of the treatment plant and the client is currently out of town, but you can google on the wolmanizing and learn about its application and effectiveness.
Ben's the quiet sort, it seems. <B>He has a Q about leaving the bark on, i suspect to slow transpiration and consequent checking. My instinct would say that the bark should come off to prevent bacteria/bugs/etc. starting to work. What do you suggest?
I didn't address that because others had, but I will say that, to leave the bark on, at the very least, in this climate (OR coast), the logs will become infested with powder post beetles and probably some fungal growth.Western Hemlock, as I said, has some great virtues, but resistance to decay and insects is NOT one of them.Let me set up a "Frenchy Test": Take a freshly cut Western Hemlock log and a Lodgepole Pine log of equal size with the bark on and leave them in the ambient air (even under cover in an open building) and the bugs will find them in no time. Unless you know what to look for, you won't know they're there, but the eggs have been layed and they will hatch and get right to work.And that's just one kind of bug. In a few weeks or months, the cambium layer under the bark will look like a Forest Service logging road map.
I sure appreciate your and all the other folk's input. While I suspected what some of the answers would be, this does give us some stuff to contemplate with the client, once we get past the holiday season.
Ben
I see some folks put up LP fence rails around here without peeling. The bark seems to eventually fall off with no damage to the underlying wood, but i guess that's just a function of our very dry climate and probably also the time of year when they put up the rails. A client up at Apgar, in Glacier Park, invited me to "listen" to her firewood pile; you could put your ear near the wood and actually hear the bugs munching. She kept the pile a distance from the house... <G>
I lived in Eastern, Oregon for awhile...climate similar to yours. Some of the newer LP rail fences were being built with poles salvaged from Pine Beetle kill tracts.The pine beetle larvae kill the trees but don't leave much more than a small hole where they exit into their beetle life.I would agree the drier climate probably limits the predation by bugs.Here on the coast, where the OP is going to do the project, there are a number of wood-infesting bugs that are drawn to the smells of down timber. Fall a Doug Fir tree and Spring, Summer or Fall, and Ambrosia Beetles will be all over it, along with powder posts, termites and others. Some of the larvae really go to town living and thriving on the sugar-laden cambium lay and leave major trails.Ever see one of those Root borer, Pine Sawyer or Douglas Fir borer beetles? They can get up to 3" long; and their larvae are even larger....enough for a meal. (I did eat one once for $5 bucks while working on a logging crew; at the time is was equal to more than an hours wages before taxes).That's one reason timber killed in a forest fire, while salvageable, loses a lot of its value if not harvested timely.The local Indian Casino, when they first converted the old plywood mill to money funnel, used large Port-Orford-Cedar and Sitka Spruce logs in a post and beam log entryway for Valet parking and the Casino entrance. They left the bark on.This last year, during a remodel and the construction of a seven-story hotel, they removed those bug-infested logs, but did a larger, expanded entry using peeled logs. Should hold up better.
I was thinking when i wrote my last post that you could probably get away with leaving the bark on on cedars, but i would have been wrong. I've never seen anything 3" long, but our firewood was full of what i guess are carpenter ants: black-bodied, segmented things that burrowed through the cambium layer. When i was a little kids and my folks perched me on firewood logs for extra weight while they whip-sawed them into blocks that those bugs were 3" long and fire-breathing, but they seem smaller now.<<they first converted the old plywood mill to money funnel>> Hey, with lines like that, you could probably write for a living! <G>
After all that's been said, there have been structures built with the bark left on.In 1905, an exhibition center was built in Portland, Oregon entirely of wood. (and bolts, nuts and spikes, not screws).The main supports were pillars of Old Growth Douglas Fir logs with the bark left on.Of course the bark on large trees like the ones in the attached photos was probably six inches thick or more and probably spiked to the tree so as to not fall off and crush visitors.My Dad took me to this landmark building when I was probably six years old....my memory of it is just the visual immensity of the wood members.Sadly, the structure burned to the ground in 1964.
I was trying to recall where i'd seen a cedar log building with the bark left on, when your picture reminded me. It's a lot more prosaic setting than that exhibition center, though it held a few exhibitions of its own, LOL. Back in the 70s, friends and i would pack up into a truck and head out of town about 40 miles to practice our jitterbuggin' here: http://www.montanapictures.net/the_lumberjack_bar_montana.htmI'm not sure what they did to stabilize it...maybe it's all the alcohol fumes and cigarette smoke preserving it. <G>
I love those kind of places. And that country reminds me of some places in the Sierras I used to hang out in. Used to be a mountain roadhouse like that in Eastern Oregon, but I think it burned down.I'm attaching some photos of a bark-covered structure that's one of my favorite get-away spots....The Chateau Lodge at Oregon Caves National Monument. The lodge is built in a ravine right below the caves,and has a creek running through the Dining room on the ground floor.The internal frame of the building is built of exposed old-growth Port-Orford Cedar logs, in a post and beam configuration. Massive marble stone fireplace in the lobby. (The caves are one of the few marble caves in the US).There is no TV, no cell phone reception, lots of nice trails, plus the caves, which are small, but extraordinary.Anyway, the lodge exterior is covered, all five stories, with old-growth Port-Orford Cedar bark.We were last there a couple of years ago and the park maintenance people had a section of an exterior wall stripped for some kind of mechanical work.I was able to see that the bark was actually nailed to plank sheathing that appeared to have been painted with some kind of dark sealer....not a petroleum emulsion, but a paint of some kind. No sign of decay...The Caves site is at an elev. of something like 4500 ft. so it's snowed or iced in in the late Fall and winter.The lodge was built around the beginning of the last century, has survived some fires and a flash flood from a broken ice dam years ago.But the bark siding material is in great shape and quite eye-catching.The Oregon Caves are between Crescent City, CA and Grants Pass, OR and one of the benefits of a trip there is some strolls through the nearby Redwoods....
Getting to this late, but many thanks for that. I have a new "must see" place on my next journey out there.