The Second Storey

After finalizing the method I would use to attach the rafters to the second floor joists, I calculated the required length using the trig calculater a few posts previous. Rudi and I carefully climbed up to the second floor, where he helped me install the first pair, more as a test to see if it could be done readily, and if the attachment seamed suitably designed. Bear in mind for weight, simplicity and style considerations, a fascia board and standard rafters with associated birdsmouth cuts was not in consideration.

The second picture shows the means of attachment I designed, using a basic hurricane bracket bent to the appropriate rafter angle, screwed down, and then the rafter glued with PL Premium adhesive, screwed from the sides, and also screwed vertically from the bottom through the joist into the rafter. Theres nothing moving here!

Making Curved Lumber

The main cantilevered deck of the treehouse is designed with a broad sweeping curve at the front, so the outmost deck joist will have to be curved to match. How to make curved lumber, in this case a curved 2 x 6? Fairly easily, if you start with decent sized scrap plywood, best thickness around 1/4" to 3/8" or so. Set up a table saw with the rip fence set at the width of the lumber you are trying to match, in this case 5-1/2 inches for the nominal 6" lumber. After ripping, this is what you end up with. The length really is not critical, as long as about half are at least six to eight feet or longer.

Back to Grade 11 Math!

With the main floor framed, the second floor joists installed, and much of the subfloor above complete, I have to now calculate the length of the roof rafters. To keep things simple I cut all my joists at the desired roof pitch of 55 degrees, and will simply intall a 2" x 3" 'fascia stop' across the bottom end of all the joists, and then butt the rafter bottoms against this stop. This means no birdsmouth cuts, just a corresponding 55 degree cut at the rafter top to mate with the ridge.

Seeing that I couldnt recall whether 'soh cah toa' (or is it toh sah coa?) was correct, and whether angles had to be in degrees or radians, I chose the most efficient option. I just googled "trigenometry calculator" and got this incredibly simple online calculator. Input two of the values you know, and the other 3 are calculated for you!

Carbide Depot trigenometry calculator

Wall Framing, Second Floor Joists

Rudi and I continued with more wall framing and second floor joists, as well as some OSB sub floor on the second (or attic) floor. Rain was forecast, so I wanted to get a rubber tarp over the second floor to protect it and the shed pine laid as the finish floor below. Some clear garbage bags offer a bit of additional rain protection

Wall Framing (Cont'd)

We continued working on the wall framing, as well as laying the finish floor on top of the OSB sub floor, immediately prior to fastening the base plate down. I decided to use a double top plate instead of a single for the long walls, and locate the joists directly above the studs on 16" centres.

A Brace of Braces

For the past five weeks or so I have been putting in a lot of work helping Jeff out at H2O Composites building canoes. I was working roughly 4 or 5 days a week 9 to 3, then at least 2 or 3 evenings 7 til midnite or so. So finally this weekend I got the second support brace installed, and pulled away the temporary support holding the main platform up. These two braces were fairly fussy, as I had to cut a couple of compound cuts by hand with the chainsaw to fit them in place properly. I still have to trim them slightly to improve their fit to the angled beam holding up the four floor beams, and after that I plan to install an additional cabling system for support. It is nice to see the treehouse up and supported the way it is meant to be. If you take a look at this photo and compare to one in the previous post, you should notice quite a difference with the temporary support removed.

Deck Foundation

As most of the deck of the treehouse will be hanging out to one side of the main support tree, I had to figure out a way to support it using the tree itself somehow, and not resorting to additional support posts. The simplest and most evident manner appeared to be using a single main 'outrigger' beam to provide support for the four floor beams away from the tree. This beam would then be supported by two angled brace posts which would then be attached to the trunk of the tree very clost to the base. I decided that this support should be angled in the same direction as the support posts, pretty much 45 degrees from vertical. I constructed four small angle blocks to support this beam (one block for each floor beam supported by it). In addition, I cut a small 1-1/2 inch notch in each floor beam to accommodate a very secure attachment of the main beam to each of these floor beams. Check out the pictures, which shows the detail very well!

Uncle John's Tree House

While we were up at the cottage on March Break, John decided to repair the tree platform he had built for his children about ten years ago. It was a great time to get together for a beer, do something fun and useful, and let Rudi play with his cousin Natalie for a while. The platform was robustly built off of two white spruces, with a step ladder up, railings around, and a slide off the side. Although it was very well built, It was not designed with a foundation system that would accommodate the growth of the trees, and of course these two little trees packed on quite a bit of girth over the course of their lives. His goal was to rebuild the foundation in a manner that would accommodate all future growth of the trees without causing any futher damage to either the platform, or the trees.

The original foundation was incorporated into the floor joist framework, and consisted of a rectangular box built around the two trees. Over the years, the trunks grew outward into the box, and eventually pulled the box apart. The new foundation consists of two 2x8 beams that are lag bolted into the trunks, one at the front and one at the back of the trees. The joist framework that supports the floor deck now simply rests on these beams, and the beams are free to slide under the joists as the trees grow. The first and second pictures show the right hand tree, along with one of the old floor joists, as well as the two new main beams underneath. Notice on the trunk the depression left by one of the (now removed) 2x6 joists making up a portion of the foundation. The third picture shows both main trunks, as well as the front main beam, two existing floor joists on each side of a new 2x6 floor joist we installed.

Dog Days of November

We had a beautiful nearly full week of weather here, Monday was wet and warming up, but Tuesday, Wednesday and Thursday (today) were glorious, highs of about 20 degrees each day, with sunny skies.

I finally cut and installed a 2x8 end beam which attaches to three of the four main deck beams (It doesn't span the four as I am leaving space for a suspension bridge to a third tree. Yes I am a bit crazy!) This end beam provides strength, alignment and proper spacing for the three deck beams. I decided that the deck of the treehouse would be irregular in shape, so this end beam is set at about a 65 degree angle to the deck beams, which made for an interesting couple of hours measuring, cutting, and installing. A bit of ingeneuity was required to singlehandedly install a 14ft long 2x8 (weighing about 40 lbs) seven feet above ground with no support!

More of the 2x6 floor joists have been raised and installed, and some brackets to prevent unwanted flex or movement have also been installed where necessary. The two steel sliders for the main support beams over the wooden bracket on the small tree have also been painted, drilled, and installed. It seems the weather is going to turn to more wintry conditions, so I am looking to finish the floor joists, and hopefully the main support for the platform on the smaller tree before the end of November.