Frame raising event in South NH follow up part two

Jim_Rogers · September 27, 2017, 05:39:48 PM

When I do a frame fit up before the raising day, I test fit every tenon into every mortise.

After fitting each tenon into each mortise, and measuring everything to ensure we have everything right, I label the tenon and its mortise. Somewhere where it won't show, but where we can still see it and use it to find the right piece and make sure it goes into the right mortise.

Like this:

Above you can see the label "9E" on both the shoulder of the housing and the tenon on the brace.

During the recent raising some braces were marked such as this "9E" which stood for post #9 east side.

Three of the four bents in this frame had three posts. Two wall posts and one center post. And one bent #3 had only two posts as it was a hammer beam bent. Thus there were 11 posts in this frame.
The posts were numbered on the plan. But they were not numbered on the post, the deck, the shoulders, the bottoms or anywhere. I didn't draw this frame, and I didn't study the plan to understand where each post was by number. Maybe that was my fault.

During the raising, as I was crew leader, I'd call for a brace to go between a post and a connecting girt and was a handed one with a label on it on the outside that wouldn't show after siding was put on. But as there was no label on the mortise. We weren't ever sure if this was the right brace or not.

Now some will say that all braces should fit in any location if everything is done right and everything is standard. And that is true to some degree.
However in bay "B" the middle bay there was a larger connector girt as it had to hold up a timber, that he called a "Summer beam". Thus the braces in the bay were shorter by two inches or so. That meant that there were 8 braces of one length and 4 braces of another. It was very easy for a "rookie helper" to grab the wrong length brace and put it in the wrong spot because the brace pocket and tenon did not have matching labels.

Also, all the connecting girts from bent to bent were not labeled on both the girt and the post.

This was very frustrating to me as I was never sure if the right piece was going back into the right mortise where we had test fit it some weeks before.

One girt tenon had to be trimmed after the bent was raised. More than one brace was very tight in the mortises, as it was placed into a different set of mortises then during fit up.

This all adds up in time. Time to trim a tenon a bit; to make sure the piece would fit. Time it took for the host/owner to run over to the cutting shed and verify the piece location with his printed plans. We had to stand there and wait for him to tell us that the piece we had was the right one or not.

I prefer to have everything labeled so that there is no question as to where it goes.

This frame was laid out and cut using the "mile rule" method, as all timbers were planed on all four sides with true 90° corner. Which was nice, the smooth timber part.
Mill rule means usually centered braces on post to tie beam. And no housings at post to connecting girts, just a mortise:

None of the post to brace and brace to connecting girt mortises had peg holes bored. Only interior braces were pegged. Exterior braces and connecting girts were all held in place with screws. That meant that each connection had to have a screw driven into it from the outside of the frame, so it wouldn't show inside. That meant each joint had to be accessed by a ladder outside the deck from the ground. We were constantly moving ladders and every time someone went up a ladder the ladder was "footed" by someone else to ensure that the ladder didn't slide off or fall over with a man on it. Safety first.

The end of each of these connecting girts only went into the post 1". No long tenon. So to secure the girt to the post we had to drive a 10" long timberlok screw into the girt and post from above where it wouldn't show after the second floor deck as added.
Upon doing this to the first connecting girt, the host/owner drill driver didn't have enough power to drive the 10" timberlok screw all the way in. And he only had that one.
Luckily, a helper volunteer had one in his truck and we used that most of the day. After a while someone got a power drill and then we had to deal with extension cords going to each ladder position every time. Another head ache, worring about tripping over cords.

Having the proper power tools for the job is a must.

Gin pole. The customer asked me to help him determine the location on the hammer beam bent for attaching the rigging to lift it. To lift a bent you have to attach to it above the center of gravity so that the top goes up and the bottom stays down. In order to locate the center of gravity, I drew the bent in my computer timber frame drawing program and it will locate the center of gravity of the assembly. Which I did.
We knew where the "pick points" were. And we attached our rigging above the center of gravity by several inches or a foot just to make sure we were high enough.

The host/owner determined the height of the gin pole. And he cut one and had it ready.
Probably my fault that I didn't verify that the gin pole was tall enough. In hindsight it should have been taller. Due to the lenght of the connecting straps and the lower height of the gin pole we ended up butting the lifting block against the stantionary block before the bent was fully plumb. It wasn't out much, and we managed to pull it in by using the ratchet strap on the back line to move the gin pole back. But we had to loosen the four line (known as the safety line) so that the gin pole had enough movement. The bent couldn't fall over and it was pulled up enough to engage all the connecting girts and their braces, just fine.
The lesson here is to make sure your gin pole is tall enough.

I just wanted to pass all this stuff on to all of you so you'd know what can or could happen. And how to prevent it so that you don't run into these issues.

Jim Rogers

Flathill · October 03, 2017, 02:52:18 PM

The Gin Pole set up took some real thought and required a lot of rope and pulley set up. Not sure if we could of been successful without having trees to tie off to.
A lot of people power to set up this frame ! Seeing most of the frame up and in place made it a really worth while day.

canopy · October 03, 2017, 08:27:38 PM

1, 2, or 3 poles tied together can be used to raise a frame known as a gin pole, shear, and tripod respectively. The gin pole seems the most common traditionally and is still popular. I've never used the gin pole, but I like the tripod method a lot. It's self supporting needing no guy wires and can be positioned precisely by one person with a simple slide of one of the legs while watching the line hanging down as a plumb bob.