RAISING DAY

We have set the day of the frame raising. It will be September 2, 2007. I'm inviting people I know so that they may be involved and to help with the raising. It is my intention to have everything ready so that the raising will go smoothly. I have never raised a timber frame, and I'm trying to anticipate everything. If the raising takes longer than one day, we'll continue as able on September 3. That's Labor Day weekend.

If you want to be involved and help, send me a message.

Building the first bent

On Thursday of last week (7/26), Mark and I laid out the rafter set for the fourth bent and fit it together. We took our time, making sure that the mortises and tenons were properly sized and drilling holes for the pegs. We also needed to chisel the mortises on the tie beam for the rafter posts and the brace. I also needed to cut the birds mouth for the rafter foot on the front of the tie beam (I forgot to cut these when I completed the tie beams nearly 2.5 years ago). I didn't take any pictures, unfortunately.

Since my previous post in which I shared my raising ideas, I've changed my mind. We will not be raising the bents completely assembled to the rafters. I thought it would be simpler and safer to raise each bent completed to the tie beam. Then, after they are raised and attached together with connecting girts and braces, we can assemble and raise the rafter sets on top. I'll still use a gin pole, just not a 30' one. The raising may take longer, but safer and simpler is better.

On Friday morning (7/27), we began assembling the first bent. We laid out the three posts with their feet on the piers and the other ends supported on blocks (scraps from cutting the timbers to size). Things went pretty well. We made sure the mortises and tenons were properly sized. I've been amazed at how the mortises have shrunk over time. I expected they would enlarge.

I've been intending to draw bore all of the joints, but not all are to be done that way. We used a come-along to pull together the posts and some of the beams and then pegged. I decided to do it that way because of how tightly some of the joints fit together, and I didn't relish pulling it apart to drill the tenon. This photo is of the first pegs I've ever driven into a timber frame.

After the bottom beams were pegged, the front post had a pretty good twist visible at the top. It straightened out when we pulled the tie beam onto the tenon at the top of the post. It was pretty neat to watch it straighten out. The other end of the scarfed tie beam over the back post was twisted. It wouldn't straighten out. So, there's a bit of a gap between it and the post on one side. I don't think it'll matter any though.

Here are some photos of the assembled bent.

It was neat to see this piece of the house come together. We'll tackle the next bent tomorrow morning.

The Garden

This isn't really about the house project, but I wanted to share some photos of some produce from our garden. We have a fairly large garden (about 200' x 70' plus another plot about 120' x 70' where we're growing squash, pumpkins, and melons). This morning's harvest just looked so nice that I had to take some pictures. The one bucket is completely full of cucumbers. The other bucket is nearly full of green beans. The small bucket has some blackberries from our thornless canes. We've already picked several gallons of wild blackberries this year. Food from the garden tastes better than anything you can buy!

Update and thoughts on raising the frame

On Thursday of last week (7/12/07), I was able to fit up the back wall of the frame. Mark the Intern helped. This involved fitting together 4 posts, 6 girts, and 6 braces and drilling the holes for the pegs. It went together quite well. However, I forgot to take the camera, so no pictures. It looked a lot like the pictures from earlier, though. It's really neat to see what I've been working on for over two years actually begin to take shape.

I'm contemplating raising the frame. Basically, I'm trying to get it straight in my head how it'll be done. I'm not planning on renting a crane to do the job. Yeah, a crane would probably make things easier, but it would also create its own challenges. I think that with enough help and a gin pole, we can get the job done safely and relatively easily. I've never done this before, so I might be wrong.

One of my intentions at this point is to raise each bent completely finished, including the rafters. Because of the design of the bent, the weakest point will be where the rafter and two posts attach to the tie beam. The only thing holding them will be 2"x4" mortise/tenon joints. My idea is to securely clamp three 6"x6"s or 6"x8"s on the back of the bent. These will be long enough to be attached to the lower beams, the tie beam, and the rafters. Then, when raising the bent, I will pull on these braces, not the bent itself. They will hold the bent rigid while they take the stress of the raising.

The gin pole I have in mind is what is called a pair of 'shear legs.' It's basically an A-frame of two poles. I 'borrowed' the picture at the right from The Mountain School. I'll probably use a couple of cedar trees since I have a lot of those here, and they'll be relatively straight and long enough. Long enough for my uses will be 25-30 feet. I won't have to lift more than 22 feet. The shear legs feet are securely anchored so they won't move. I'll probably set them in a couple of holes and chain them to a couple of my foundation piers. It'll also be secured by lines to anchors or trees toward the back. In barn raising from this photo, they used a block and tackle rigging and raised their bents with human power. I'm planning on using a tractor to supply the power to raise the bents.

I'll continue pondering on the raising. I want it to go well, smoothly, and relatively quickly. It'll be an exciting day, I'm sure. I don't know when it'll be yet, but I'll be sure to announce it and invite lots of help!

Cutting a Tenon

I had a few beams to redo the joinery on because of warpage. As I was working on these, I decided to share the process for cutting a tenon. The beam upon which this tenon was cut was a girt along the front wall of the house. It is a 12' long 6"x8" oak beam. It's simple in that it has a 1-1/2" tenon on either end. Because of its location in the frame, I didn't need to cut mortises for braces. Additionally, I needed to make sure that the tenons were the proper height since the original timbers from which the girt was cut was not a true 6"x8". I had notes on the correct height, so matching that isn't a problem. Since this girt will help support the floor, it is important that the top of it is on a level plane with the floor; the bottom level doesn't matter. This post details the process of cutting one tenon. The tenon on the other end was cut the same way.

The first thing to do is to sight down the timber to determine the crown. That is the edge that bows upward (hopefully only slightly if at all). The crown side should be on the top when the beam is in the frame.

The second step is to square one end of the beam. I measured to make sure of the length and if there were any imperfections (knots, primarily) in the timber that would be good to work around or avoid. Then, using the framing square, I mark a square line all the way around the beam near the end. This line is the guide for cutting the beam square.



Then, using my circular saw, I cut along the line on the waste side of it. This saw doesn't complete the cut because it can only cut about 2-3/8" deep. So, I widened the kerf on one side by running the saw a second time. This allows my cross cut saw to fit into the kerf easily. I use this hand saw to complete the cut. This yields a squared end on the beam.

The tenon is to be 4" long. Because this girt is along the outside edge of the house, the tenon is set 2" from the outside. So, using the framing square, I lay out the location of the tenon, marking it clearly with a pencil.

Once it's laid out, it is time to begin making the necessary cuts to create the tenon. I use the circular saw and cut along each of the lines. It is only on the 2" deep cut along the outside edge that I need to adjust the depth of the saw's cut.

Once I've cut along all of the lines, it's generally easy to remove the chunk of wood on either side of the tenon. Sometimes, there is a knot hiding inside that makes this process more difficult, but when the grain is straight, it doesn't take but a couple of blows with the mallet on the end of the chisel to pop off the unneeded piece of the beam.

At that point, I'm left with the tenon with some areas that need to be cleaned up with the chisel. It doesn't take long to pare off the excess wood, leaving a smooth side on the tenon. I then need to check the thickness of the tenon to assure that it will fit in the 1.5" mortise that's already been cut in the post. I used the width of my 1.5" chisel to feel if the edges of the tenon are the right thickness. I also use a straight edge (like the edge of the chisel) to check for high or low spots along the sides of the tenon that need to be corrected.



Because the mortises are already cut for the girt that I'm replacing, I needed to make the tenons on the replacement the right size to correspond with the mortises. Generally, they need to be made smaller. I simply take the necessary amount, whether 1/2" or 3/4", off of the bottom of the tenon. This allows the tenon to fit while leaving the top of the girt on the same plane as the other beams/girts that support the floor.

Figuring out how to cut a dove tail tenon for the floor joists

As I worked on the braces, I gave some thought to one of the next steps in the project: cutting the dove tailed tenons on the ends of the floor joists and purlins. Cutting the mortises for these tenons wasn't too difficult, but I hadn't given much thought to how to cut the tenons. I just knew that I would do so at some point.

The floor joists and the purlins will all be 4"x6" oak. One of the features I want to incorporate is an arc from the tenon into and toward the bottom of the joist/purlin. It will provide a nice aesthetic touch and should help mitigate some of the potential weakening caused by checking as the wood dries. As I considered my intentions, it became clear that I didn't have the right tools for this job. It seemed that a band saw would be a good choice, but a stationary one would present some challenges when working with 12 foot long pieces of oak that weigh 100 pounds or more (depending on how much they've dried while in storage).

Several companies make a portable band saw. Generally, these are used for cutting metal. Apparently, they do a pretty good job of that when equipped with the right band saw blade. I thought that if I had the right blade, this would be a good tool for my purposes. So, I searched on Ebay for one. I didn't want to spend the $260 or more that a new one costs. I eventually won an auction for a used Porter Cable portable band saw. I ordered some 6 tooth per inch blades from MK Morse. After receiving the saw and the blades, I had to try it out.

I marked the dovetail and a shallow arc on the end of a short piece of 4"x6" oak that I had in the shop. I then tried to cut it out. When I was done, there was a dove tail tenon on the end of the timber, but the cuts were a bit crooked and wavy. I marked the other end and tried again. Then, I chopped off the first end and tried a third time. By paying careful attention to the orientation of the saw and making sure I stay on the lines on both sides, I was able to cut out a decent dove tail tenon. I'll practice a bit more before I begin on the 100 joists and purlins that I'll need for the frame. But, at least it looks like my idea will work.

Note-taking during the project

Building a house is a big project. I've tackled the job from conception to finish, and because of finances, I'm not paying someone else to do my thinking and planning for me. Just the timber framing aspect is a large undertaking, as I designed the frame and am completing all the joinery on my own. I'll also be directing the raising of the frame. In light of the immensity of the project, I knew that I needed to keep some notes as things progressed. There are a lot of things that I could potentially forget. So, I have a framing notebook in which to keep my notes all in one place. It may not be the best organized notebook, but it seems to serve my purposes.

When I first began the joinery, I didn't have the notion or the space to lay out all of the timbers I bought to determine where they each would go. I could've chosen which post timbers were to be which post, which beam timbers were to be which beam, etc. But, I didn't. I didn't even think about doing that. I began with the timber on the top of the pile and called it whatever I had in mind to work on next. I did have a method, completing the beams first, then the girts, then the posts, the rafters, the braces, and then floor joists and purlins. I kept notes on the timbers as I progressed.

I also made an assumption that I didn't realize until later wasn't true. I assumed that the timbers I had ordered to be 8"x8" were actually 8"x8" and that the timbers I ordered to be 6"x8" were actually that, 6"x8". they were close, usually, but few were actually as I had assumed. There were timbers that were 7-3/4" at one end and 7-1/2" at the other, or ones that were 8" at one end and 7-1/2" at the other. There were some that were consistent from one end to the other, and some that were truly the dimensions I assumed they would be.

When I realized that my timbers were only nominally sized, I knew that I needed to clearly record their measurements to help assure some degree of levelness for my floors. There are different approaches to timber framing, like scribe rule and square rule. I've worked with a modified square rule approach, meaning I've done what made sense to me. If I had known that the timbers were not truly sized, I would've done some things differently. But, I didn't, so I didn't. I cut the tenons on the ends of the beams and girts to the full depth of the timbers, whatever they were. I then noted the depth for each end for each timber. This allowed me to make sure the mortises on the posts were the right size and placed so that the floors would be level, not varying by up to 3/4" from one post to another. My reference point for each mortise was the side of the beam or girt that mattered, generally the floor side.

I've kept notes of other things, like spacing and location for floor joists and roof purlins. I've also noted the size, shape, and location of tenons and mortises. This has been important since the beams, girts, and posts have been completed with varying amounts of time in between, literally months or over a year for some of them. We'll see how well it all goes together. I suppose that will be the real test of my note taking.