How to Build a Shadehouse

Issue #2

June 1995

This converted backyard shed is now a shadehouse
that can grow thousands of tree seedlings per year

The mission of (established online May 1995), most simply put, is to double the timber volume of the world in 50 years.

In the urban forests of the world, this same goal applies. That is, we’ve got until May 2045 in which to double the timber mass of the urban forests throughout the world. This task however, should be the easy one compared to growing the forests of the vast natural forest regions on planet earth. Moreover, what we learn about growing trees when we double the number of trees in each major world city will be valuable knowledge to take with us into the back country, where the great natural forests grow.

Do you want to grow the great trees of the world? Would you like to plant these trees in your urban forest? All you need is a small greenhouse, and you can propagate thousands of these trees each year. A goal of EcoWorld’s web site is to create a database where you can learn what great trees, “flagship” trees, will do well in your local climate and soil. Our goal as well, pursued in this article, is to show you exactly how to grow these trees. It’s not really that hard to grow these trees, it´s lots of fun, and it’s relatively inexpensive.

This article will show you how to build an inexpensive shade house using a converted backyard storage shed. Of course this means you’ll have to empty the storage shed, since now it will be for trees instead of old stuff. But if you really try, this won’t be so hard. Go to the goodwill. Have a garage sale. Put some flooring in your attic or garage rafters and create a new storage area. You have options.

Most readers probably are familiar with the the common homeowners sheet metal storage shed. They vary in size, but the type that I have modified into a shade house (soon to be a greenhouse) is fairly typical. It stands around 6´ 9″ at the peak, with a shallow roof pitch leading to 6´ sides. The floor dimensions are 8´ deep and 10´ wide.

Hidden underneat the sheet metal skin of most backyard sheds is a wood frame that can form the nucleus of a very inexpensive greenhouse.

The first step is to remove the sheet metal, starting with the roof. The sheets can usually be unscrewed in a short time using a portable electric screwdriver. As you take each wall off, nail 30/60 or 45 degree cross supports into the horizontal wood framing. Be careful as you perform these modifications, of course.

The next step is to remove the wood floor. Pry the nails out with a claw hammer and screwdriver, then saw through the wood along the with a skill saw that only goes as deep as the thickness of the plywood. This way you will be able to save the floor joists that are underneath the plywood and use the to reinforce the frame. If you’re lucky, underneath the floor joists will be a nice concrete slab.

Now you are ready for the hard part, but also the most fun. Using 1×2 8´ stakes, build three “gambrel” roof arches. Cut the stakes into 3´ sections, and use four sections per arch. The outline of this new roof is like a classic barn roof, with angles the same as those on half of an octagon.

To connect the roof arches use 9´ long 1×4 rafters, which need not be precision milled and can be obtained for around USD$3.00 apiece at a good lumber yard. The reclaimed floor joists can be used to reinforce the roof and to buttress the corner posts, as well as a post on the mid-point of each side beneath the points where the middle arch sits.

Right now we are just making a shade house, so at this point you are pretty much done. Put the door back on, then it’s a good idea to either seal or stain the wood. You will need one gallon of sealer or stain, and be sure to use a 3″ roller. Using a brush will take many, many hours more than a roller. When you add pieces later to either provide additional reinforcement to the frame or to create shelving inside, it’s best to seal or stain the pieces before affixing them to the structure.

Last of all drape shade cloth over the entire frame. The best way to do this is to use just one piece to go over one side, up and over the roof, and down the other side. Such a piece would measure 8´ by 18´ to go halfway down each side, or 8´ by 24´ if you want the shade cloth to reach the ground on each side. Shade cloth like this can be ordered pre-cut from any reputable nursery supply company with hems and grommets every few feet. The grommets allow you to tie the entire piece to the greenhouse frame with a few lengths of stout twine. A shade cloth this size yielding 50% filtration costs only around $35.00. Your best bet for the front and back is shade cloth cut to the dimensions of the front and back and stapled onto the frame securely with a staple gun (greenhouse makers: follow all above directions but use sheets of clear plastic instead of shadecloth – be sure your structure can withstand the wind in your area).

Imagine how many trees can be spawned in such a shadehouse. The average starter tube tray holds 50 tubes per square foot. A greenhouse with floor dimensions of 8´ by 10´ can support 60 square feet of starter tables, or 3,000 tubes. Allowing for some spoilage, you can figure it is possible to start 2,500 trees per year in this converted backyard storage shed. The entire cost of this system, including a sprinkler system, is under $200.00.

To put this in perspective, Northern California’s Santa Clara Valley is estimated to have around one million large, canopy trees. One million “flagship” trees that clean the air, retain moisture, increase rainfall, and moderate the temperature. These trees have an average lifespan of 100 years. Only four of these little backyard greenhouses could actually maintain an urban canopy of one million trees. Putting it another way, if you had a big yard and built a greenhouse a mere 48´ x 20´, producing 30,000 trees per year, you would not only maintain the urban forest of a million trees serving a metropolitan area of 1.5 million persons, but you would increase the size of that urban forest from one million “flagship” trees to an urban forest of two million such trees within the 50 year deadline.

Clearly reforesting the urban regions of the world is not as tough as it may seem when first contemplated. Our first EcoWorld nursery should be able to turn out 2,500 trees per year, and many of them will be grown to be much larger than seedlings. Thousands of Sycamores, Cottonwoods, Oaks, Redwoods and other types of trees are already beginning to march forth from this first greenhouse and nursery and into the earth.


—–Original Message—–

From: Cheryl Lynch

Sent: Monday, February 17, 2003 1:36 PM


Subject: Gambrel roof

Could you please help me? My husband and I are building a workshop and we want a gambrel roof to house various woodworking and craft projects. I have looked on the web to find the angels needed to construct the roof and came closest to understanding what is needed by your article. Could you please give us the dimensions so we can draw up the plans?

Thank you for any help you may be able to give.

Cheryl Lynch

When designing a gambrel roof first develop the view of the structure from the end. To design this view, the main thing you should to know is the angle of the roof rafters that form the cross-sections of a gambrel roof. Think of a gambrel roof (viewed from the end) as half of an octogon, that is, half of a stop sign, where two of the points intersect the ceiling line. This will help you visualize the gambrel shape. Make an octogon and draw a line through two of the points to cut the octogon in half. When designing the cross sections, the angle of the top beam and the two beams to the right and left all need to be exactly 135 degrees. All four pieces of each roof cross section need to be equal in length. I hope this helps.

Ed Ring



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