Saturday, May 22, 2021

Chinking 101

First step in the process was setting up the mixing station. As there is no running water at the cabin I would need to bring in my own supply. This would be done by filling a 30 gallon garbage can in the truck then using a fountain pump to transfer the water to the two milk cans. The mighty mixer was a labor saver that would mix the batches of premixed mortar. About half a bag at a time. All I had to do was add water and turn it on! Not knowing how many 80 pound bags of mortar I would need I ordered a full "cube" 40 bags! Yikes that was 3,200 pounds for a 1/2 ton truck.

Some of the gaps between logs were pretty wide and required the placement of a strip of wire lath to be inserted to hold the first coarse of mortar as shown here. 

This had to be done on about 3/4's of all the logs, inside and out! Note: 12 by 14 cabin = 52 foot perimeter times 12 logs high = 624 linear feet x 2 (inside and out) = 1,248 feet. So that's about 1,000 feet of first coarse filler mortar and then another 1,200 feet for the finish coat of mortar.

I decided to practice on back side of the cabin to get the hang of it first. The design of the mortar joint is such that the top edge of the mortar is pressed back at the top and then brought out to the edge of of the log below it. Doing this forms a drip edge at the top and a slope that sheds the water off the log below. This is super important for the life of the logs and cabin. 

So this is what it looks like after it is cleaned up with a scraper and wire brush to remove any excess mortar from the log surfaces. You can see the sloping detail of each joint at the edge of the window frame.
Almost done with 1/8 th of the cabin.

The final step for the outside is to give the logs and mortar one last coat of the Honey Gold finish.

The inside joint is cut in a bit and held back from the face of the logs. I did this to bring out the log work more. After scraping and wire brushing off any excess mortar a nice coat of gloss polyutherane finish was applied. So it looks like 30 bags of mortar will do the job and should finish the other walls next week.

Then, while the cabin is drying it will be time to get back to work on the Treehouse Project. Here is the electrical service that I ran out from the cabin to the tree.

Friday, May 14, 2021

Phase IV Treehouse Support Structure Complete


Just as the foundation is one of the most important parts of building a house so is the supporting structure for a Treehouse. Fortunately this Oak tree is dead so I did not have to keep the health of a living tree in mind when I attached the supporting beams to the tree. 

Beam material would be 2 by 8 rough sawn Oak plank. Since the pieces I had were not 10 feet long I needed to lap and screw two pieces together. This would not be a problem as each beam was going to be supported in two places about 2 feet from their center point by the 1 foot diameter tree limbs in the crotch of the tree.

Doing all this from 30 feet in the air was not going to be for the faint of heart. But a good learning experience and some "serious fun".

I choose 2" square box tubing and 3/16 by 2" flat stock to fabricate the braces that would help carry the load of the 1675 pound Treehouse. You can see the braces on the model. A change in the elevator design shortened the length of the beam shown on the model by about 3 feet so it will not be sticking out that far to the left.

OK, the first two main beams, shown running from left to right were notched into the tree. The notch gave the beam a positive support point that would carry the load and would only need screws to hold them in place. Rubber roof membrane was placed over the exposed end grain of each notch to keep out any water. Although I don't see this as being much of a problem as the finished Treehouse will be covering this area.

You can see the ladder has been extended by clamping a section of aluminum ladder to my 24 foot fiberglass extension ladder. This got me right to the crotch of the tree and eliminated the need to climb the 2x4 steps screwed to the tree. It also brought visions of a poster I saw in a local business showing various jury rigged things like this and was titled, "Why Women Live Longer Than Men!"

With the first two main beams in place a center mast was installed that provided two attachment points. One for the rope and pulley to bring up tools and materials until the elevator is in operation and a second point for a safety harness line. This point was offset and can swivel so I can work around the perimeter of the Treehouse and not get wrapped up like a dog on a chain.

You can also see the first of the four diagonal braces hanging from a second level support beam.

Things are moving right along now. With the first set of diagonal braces hanging down and ready to be attached to the tree trunk. 

Strength, load path and tying everything together is always my main concern. I know the tree trunk could stand it because it survived the wind storm that tore away the massive tree top several years ago. I needed to make sure those forces, should they occur again not knock out the Treehouse and send it crashing to the ground. Or worse land on Cabin #6! To accomplish this each of the second level beams, crossing at right angles to the main beams were tied together with ready bolts and plates like this.

So all this might look easy but I can tell you a project like this keeps you on your feet and there are plenty of things to consider if the outcome you want is to be square and level like this. In a tree. Thirty feet in the air no less.

Oh wow, went as planned, so far so good.

Imagine the view in the fall and winter. All 360 degrees of it.

Next up, Phase V Disassembly of the Treehouse and Placing the Floor.

Saturday, May 8, 2021

Phase IV on the Treehouse Project


Phase IV involves the building of the supporting structure in the top of the tree that the Treehouse will be attached to.  Pictured is the model of the structure that I am talking about. This will be tricky in the beginning as there will be little to secure safety ropes to and the ropes will also be below the level of work I am doing for the start.  

OK, three hours later the first board is up and secured in place. In preparation for this the extension ladder was placed and tied off at the top to the tree. Then the lad slide rope was attached, as high as I could reach, to the limb on the right with the climbing steps. With the climbing harness on this allowed me to safely go up and down the rope to this point. Now the picture doesn't show it but the climbing steps lean a few degrees out from vertical. This causes a bit of anxiety. I then taused two more rope slings through the crotch at the top and secured them. This gave two more points to attach my safety harness leads as I moved up. Being cautious always to be secured by three points as I climbed.

One of the main concerns in this project is how the 1675 pounds of Treehouse dead weight will be distributed. This first support is a 2.5" by 8" piece of rough sawn Oak. The tree trunk was notched to form a flat support for each end and the piece was secured to the tree with four 1/4 by 6" GRK screws. Also as an extra precaution against rotting a piece of rubber menbrane material was placed one the end grain of the notch area on the tree. 

So now the safety rope for the lad slide is secured to the top of the highest point on the left limb and I will get to work on the putting up the second main support piece in the same fashion. In the mean time...

It has been a year now for Cabin #6 and it is time to also get back to work on that. The process of chinking has begun. This required a work station for mixing the mortar that will be used for the job. As there is no running water at the cabin and the mortar will be stored outside this all had to be planned for as the chinking process will take several weeks.

Fired up my trusty new mixer and it is perfect for the job. Making a 5 gallon bucket full of mortar mix per batch is just right. The mortar is a colored pre-mix having all the sand, lime and mortar in it. All I need to do is add water and mix.

Chinking, first go at it. Will practice on the back and outside of the cabin to get the hang of it. Some of the larger gaps have wire lath in them but either way it is going to take at least two layers of mortar to fill in the gaps in most places. On the outside it is important to run the mortar so that the top edge is under the edge of the top log by about 1/2 inch and then runs out to the very edge of the bottom log. This make the top log a drip edge and prevents the water running down the wall from being able to get behind the mortar joint to rot the logs. This is an important detail in the chinking process!

So after a couple of hours and 2.5 bags of mortar the back outside wall has the first layer of mortar in it.



Saturday, May 1, 2021

Window and Parts Delivery System


Would a window for the treehouse even fit through the opening? Well using a copy of the windows cross section profile, nailing flange and all it looks like it will just clear ("Just the way I planned it!").

So I designed a temporary platform with some 2x4's and scrap flooring that will serve as the base to place parts and windows on to be lifted up to the treehouse for assembly.

Successful test of the system with the a window.

So windows will be brought up then layed on the floor and tipped up from the inside and mounted. This method works like a charm and only the bottom nailing flange needs to be done on the outside with the window slid open.

 Last but not least would be fitting the roof membrane. I had ordered a 15' by 25' piece and wanted to make double dog sure that I could make it cover. A 1/8 scale model was made of the roof and membrane material. 

After thinking about it for a bit I realized that the distance from Side to Side of the hexagon was 14'. this would allow the required amount to cover the roof and fascia (again just as I planned). Measuring from Point to Point of the hexagon was around 18' because of the diagonal of the right triangle roof pieces. So the direction to run the roof material and which edge to start with was determined. The area of the roof hatch would be where the gathering of the 100 pound membrane piece would take place.  

OK. The piece fit and the overhang would be trimmed back a bit to make the final adjustments. A small piece would be required to cover the edge in front of the hatch. There would be plenty of material left to cover the hatch.

Since this is a pre-assembly step the edges of the membrane were left long and are only tacked in with 1/2" staples on the underside of the roof. This way I will have plenty of material to work with when I do the actual job when the treehouse is 30 foot in the air!