Project of the Month: Tree of life

In July 2008, The Creative Landscaping Co. was asked to design and construct a special treehouse garden structure for 2- to 5-year-olds. It was not to be built on posts, and there was a short list of inclusions:

• hidden trapdoor entry;
• Dutch door with a magnetic chalkboard;
• a fireman's pole;
• rope balusters; and
• to utilize, at least some of, the bamwood found in the family's farm barns.

Those initial requests quickly grew to include a 250-sq.-ft. play platform at a lower level, 11 ft. above ground level. This addition pushed the treehouse an additional 5 ft. above the platform, for a total height of 23 ft.

With the initial request, Harper was emailed a picture of "The Tree" (pictured at left, pre-house): a 68-in. Cal maple, which he describes as "in excellent condition and whose shape was just ready-made for a treehouse."
After checking with the National Arborists Association, it was determined that the health of tree would not be compromised with the minimal attachments the design was going to make, as long as "sliding joints" and cables were used. Harper was required to not "stack" lag bolts, such as with a ladder straight up the side of the tree. Because of the size and health of the tree, cabling was not deemed necessary.

The initial mock-up of the house was accomplished at Creative Landscaping's shop. "We have been constantly asked how we achieved the designed curved shape of the roof and sides of the house," Harper says. "We simply used 1 in. x 10 ft. material to determine the shapes — by trial and error — and when the shape was acceptable to me, we cut the final (treated-lumber) framing pieces out of 2 in. x 10 ft. material."

All exterior surfaces of the structure are western red cedar and redwood. Nearly all fitments are stainless steel, except for the construction framing hardware, which is galvanized. To avoid the "built-on-posts" look, the team used 7000# cables, fabricated by a local mining supplier, slide joints and a knee brace — although one supporting post is in place. All attachments to the tree were made with 3/4 x 10 in. and/or 12 in. SS lag bolts.

The rope balusters were accomplished with nearly 600 ft. of marine-quality rope, wrapped twice at the top and once on the lower rail. Rope was wrapped around, not through, to delay any premature breakdown.

Because the house was constructed almost entirely on the ground, a crane was used to place the structure on the pre-constructed base, 16 ft. in the tree. "We had a very good operator who placed the structure in less than 15 minutes, and barely a leaf was disturbed," Harper reports. Final details were accomplished with the house in place.

The first weekend the project was completed, the "homeowners" had 30 mini- and full-sized visitors. The tree and the structure have since survived the winds of Hurricane Ike, two winters of snows, ice and winds, other gatherings and parties — and are still fully intact. "After 35 years, it was marvelous to have two clients — albeit only 5 years old — who absolutely loved the project and everything we did for them. Everything. Life was good," Harper says.