Faux Roof for Red Box
Covering another shipping container
Here at Windward, we delight in reusing shipping containers to address all sorts of sustainability needs. For example, we have two 40' shipping containers on the landing that are set parallel and twenty feet apart. The space in the middle is covered with standard twenty foot greenhouse arches, thereby creating a 20'x40' sheltered area in between the containers, the sort of place where we can do serious maintenance work on equipment like our backhoe during the snowy parts of the year. The concept worked, sort of in that the plastic roof kept the rain and snow off of the main area, but water just ran down the walls of the shipping containers creating a small pond in the center of the work area.
Shipping containers have a flat roof, so when they're set level, the indentations in the roof create little ponds which eventually rust out the roof. One solution is to build a false roof over the container with enough slope that the rain doesn't collect on the roof. We finished the first of the faux roofs this spring; for information on that work, Click Here.
One of the not-so-obvious rules of sustainable energy systems is that you need water to generate energy, just as you need energy to use water. For example, you wouldn't think that photovoltaic systems need a lot of water, but actually they do in that even a small amount of dust and grime can significantly reduce the amount of power they generate. In order to key an array at maximum productivity, it has to have regular washings with distilled water during the dry season. In our case, we'll need distilled water to feed our solar boiler since the salts dissolved in ground water would quickly foul our boiler if we use well water to operate the steam engine.
Fortunately, we have a large supply of distilled water available in the form of rain--all we have to do is collect and store it, and we're ready to generate steam. By installing the two faux roofs over the containers, along with the UV stabilized plastic over the center area, we'll be able to collect better than twenty thousand gallons of rain water each winter. In addition, we get a large, dry place in which to work on equipment during the wet season, and the insulated faux roofs will go a long way towards converting the containers from ovens into comfortable workspaces on those hot, summer afternoons.
The first step was to cut down one a tall Ponderosa pine that died two winter back, buck it into ten foot lengths, and haul it down to the sawmill. Sarah's become quite proficient with the mill and quickly cut the logs into the boards we'll need to make the forty-foot long gluelam that will hold up the inside edge of the faux roof.
Sarah "flying" the saw blade through the log
When you buy boards at the lumber store, you quickly learn that a 2x10 isn't two inches thick and ten inches wide. Those numbers refer to the rough sawn dimensions as boards are cut from the cant. After cutting, they're usually stacked to dry, and only later are they run through a planer that creates the smooth surface you see when you buy lumber at the hardware store. The planer trues up the edges, but it does so by cutting away material to the point where what was originally a two inch thick board is only about one and a five-eighth's in thickness. In our case, we'll use the rough sawn timber as it comes from the sawmill, saving time, energy and actually producing a stronger component. We won't need to set the lumber to dry because we're cutting from a tree that was already dead and dry.
taking another slice off the cant
The next step was to create a forty foot long beam by nailing and gluing the 2x10's together, staggering the joints. This technique allows us to create a strong, stable beam that's as long as we need to do the job.
starting the gluelam
One trick is to have someone stand on the two boards as they're nailed together.
getting near the end
It took a while to mill out the rafters since as we worked our way up the trunk, each ten-foot long section yielded one less 2x10, and we needed 21 of them in order to place a rafter every two feet. While our primary goal was to get as many 2x10's as we could from each log, we also were careful to use the rest of the log to produce the 3/4"x6 inch planks that would form the deck. We also milled out some 1x6 inch planks to nail to the end of the rafters to hold up the gutters that will be used to collect the run-off. The collected rain water will be stored for later use in our steam engine.
The intermittent fall rains have been holding up work on Red Box's faux roof, but a couple of hours now and then between the rain squalls is adding up. Once the decking was laid down using the ring shank nails that were developed after Hurricane Andrew--it's best to place the nail where you truly want it because they don't come out--the faux roof started feeling nice and solid underfoot. Six inches of fiberglass batting was laid down on the top of the container, and then it was time to start screwing on the metal roofing.
While other places have to build with earthquakes or hurricanes in mind, about the primary natural disaster we have to keep in mind is forest fire. One of the key advantages of sheet metal roofing lies in its ability to shed glowing embers as though they were drops of rain. When one of our neighbors lost their home to fire, you could see the embers raining out of the sky and dripping off their barn's metal roof, a sight which left no doubt that had the barn's roof been made out of shakes or asphalt shingles, that building would have been lost too.
Andrew and Oana take joy in seeing
this project near completion
Since Red Box's roof won't be very visible, we're taking this opportunity to use up the bits of roofing left over from other projects. The roofing is available around here in two shades of brown, and over the years we've used both, so when we looked at our remainder pile and saw that there was a considerable amount of both shades, we decided to go with this alternating "color scheme." A key element in any sustainable program is thriftiness, so we're pleased to be able to use up our roofing scraps in this way.
With Red's new roof, as with most of our capital projects, we put in a couple of hours a day--weather permitting--with the result that progress sort of "happens" without the sense of always being rushed. That's not to say that nature's inevitable timetable doesn't rule, because whether it comes early or late, serious winter is coming, but after having lived on the edge of the Cascades for two decades, we're pretty familiar with what needs doing and when. For example, a good deal of our community work time is currently involved in doing the fall butchering, but by balancing the recurring projects with work such as putting this secondary roof on Red Box, we get to enjoy both a sense of continuity and the pride of making tangible progress towards our goals.
For me, it's that blend of continuity and progress that makes this life worth the challenges.
our scheme of alternating tan and dark brown worked out nicely
Two days back, we hauled another log down to the saw and milled out a selection of 1x6s. Yesterday, we hauled them up onto RedBox's new roof and used them to make a 2x6" glue-lam. We were careful to not sink any nails in the middle two inches of the glue-lam.
Today, we set the worm-drive skill saw's blade to 45° and cut the glue-lam in half the long way. The two resulting glue-lams will be used to secure the plastic roofing that will be stretched over the hoops between the two containers.
Katie uses the skil-saw to cut the glue-lam in half
Today, we set the worm-drive skill saw's blade to 45° and cut the glue-lam in half the long way.
One of the glue-lams remained on the top of RedBox while the other was moved over to the top of GreyBox.
The past few days have brought overcast days with intermittent rain, conditions which make working on a sloping metal roof more "exciting" that we care for, so work is proceeding during the intervals when the sun breaks through and the metal dries off. No real impediment, since there's plenty else to do, but we have hopes of getting this project wrapped up before the snow comes.
Andrew drilling holes in the hoops
The next step was to nail a run of 6" wide aluminum to what would become the underside of the glue-lam. This would assure that the rain coming off of the plastic covering the "bridge," the 20'x40' section spanned by the metal hoops, would be conveyed to the metal roof so that it would run down and collect in the gutters. The problem we had the first time we put plastic on the bridge is that much of the water collected ran down the inside walls of the containers, turning the 20'x40' area into a pond.
With the flashing attached, the next step was to drill 1/4" hole into the hoops so that we could use lag bolts to secure the glue-lam to the greenhouse hoops. With the glue-lams secured on both sides, the construction part of this project is finished.
The county road crew recently when along the county road that forms Windward's eastern boundary taking down trees that had died due to beetle kill and which would eventually be blown down by a heavy wind or pulled down by a heavy snow. Better to take them out now while the weather's good than have to deal with them when it's not.
Some of the Ponderosa pines had fallen victim to this year's dry summer, and were in excellent shape for milling into lumber of various sorts, including the 1x2" and 3/4x2" battens we needed in order to secure the plastic cover to the bridge. For projects like Vermadise where we remove the plastic cover each spring and replace it with shade cloth, and then do the reverse in the fall, we use a metal track shaped like a capital letter C and "wiggle wire" to secure the material in a way that allows us to remove it easily. Untreated plastic will only last one summer before the ultraviolet rays degrade it to the point where it loses its strength, but for this application we used plastic formulated to resist that sort of deterioration. The covering is rated for three years, but we've gotten as many as five years of use out of it before.
Andrew gives scale to the bridge
We used the more rigid 1x2" battens and duplex nails for the long, straight sides, and a more flexible 3/4x2" batten and heavy constructions screws to secure the plastic to the arches.
We're very pleased to see this project reach this level of completion. There's still plenty more work to do since we eventually want this area to become greenhouse space that's heated by waste heat from the steam engine, but for now we're delighted to have a huge, dry area in which we can do maintenance or work on large structures such as the parabolic solar trough reflectors without regard to the weather.
A special thanks goes out to Annie, Oana, Andrew, Katie, Kerst, Sarah, Opalyn and Nathaniel for the important work they did in moving this project forward!
This fall, winter seemed to be on hold as we worked to finish the last details on installing the Bridge's 6 mil poly roof, but in retrospect it appears that winter was marshalling its resources in order to make this a winter to remember. Already, we've had more than two feet of snow, and overnight temps as low as 2°F. One can only wonder at what winter--which has a good two months yet to run--has in store for us this time around.
a view from the south entrance
The goal is to use the Bridge to provide a winter-ready place where we can do maintenance on our larger pieces of equipment such as the backhoe. We weren't able to get the space cleared and work-ready before snowfall, but we got close. In a month or so, the snow will melt and we'll be able to use the space as intended--assuming that the melt doesn't take the Bridge down.
If we're lucky, the snow will melt slowly and soak into the ground--the fortunate key there being that we had a blanketing snowfall before the cold temps set in so the ground under the snow isn't frozen. The worst condition is when a heavy snow such as this is followed by a warm, steady rain which the snow sucks up like a sponge getting heavier and heavier. Eventually the snow turns to mush and runs off downhill across the frozen ground, often taking the Klickitat river to flood stage.
The last time that happened, a quarter of the road between here and the Columbia was washed away. The county used Federal disaster funding to rebuild the road higher and with larger culverts, so the road bed is less likely to fail so badly, but nature always bats last.
The hope is that the steel hoops that form the bridge are buttressed strongly enough by the faux roofs we created on top of Gray and Red box that either the combined structure will hold the weight as the snow melts, or that the 6 mil plastic will fail before the hoops. We'll let you know how things turn out.
The weather has been slowly warming and last night brought the rain which usually signals the end of any given snow event--as well as raising the question of whether the Bridge would be able to hold both the weight of the snow and the rain that it would initially accumulate.
As you can see, the rain was able to melt away much of the accumulated snow without its weight buckling the steel arches that formed the Bridge. That's what we had expected, but it's never the sort of thing one takes for granted since we have lost hoop structures in past winters. For example, back in the spring of '96, we lost a 20'x60' hoop greenhouse that we were using as a milking room. Here's a pic of what that looked like when the snow eventually melted.
Notes From Windward - Index - Vol. 68