rafter design?

[lazy-river]

HI Folks,
Great forum, first time post.  I am in the process of working on my first timber frame. 12 x16 two story outbuilding with a 6/12 roof pitch. The principle posts go about 14ft.  All three bents are together and lined up on the ground ready to go.  The sill plate is also ready to recieve the bents and all appropriate ties are cut out and also ready to go.  I am using recycled rafters which will actually be their third time used.  Rafters are 8 ft long and they are about 4x5's.  I would like to just lap and pin the rafters so I can stand in the second floor, but with a 6/12 pitch(22.5 degrees?), do I run the risk of a weak joint at my peak?  Again, this is my first timber frame.   Any thoughts?  No pics as of yet, but I can provide in a week or so.

Also, we tried to lift the first bent with seven people and had some trouble.  I am going to explore using a few come-alongs and a few more people, or rounding up some heavy equipment?  Again, any thoughts?

I am located in central pa.

Thank you again for the great forum.

take care.

Andy

[Tony_T]

Also, we tried to lift the first bent with seven people and had some trouble.  I am going to explore using a few come-alongs and a few more people, or rounding up some heavy equipment?  Again, any thoughts?

I am located in central pa.

Thank you again for the great forum.

take care.

Andy

Hi Andy,

Might want to construct a gin pole to raise your bents.  A good stout oak or ash tree with a strong limb a little taller than what you are lifting (to secure a block and tackle), block and tackle, ropes, and pulleys are needed.  You can set things up so there is no danger of the bents coming back down on anyone using the gin pole (e.g. no one lifting underneath the bent).

[ohsoloco]

Welcome to the forum, lazy-river 

Where abouts in central PA are you located?  I'd love to go to a raising.

[lazy-river]

thanks ohsoloco,
Just over the mountain.  Follow route 26 south out of state college toward Huntingdon.  In the town of McAlevy's Fort, route 26 makes a hard right.  Just beyond the Fort, you will cross over Standing Stone Creek into the village of Ennisville.  The first place past the bridge on the left is it.  You can't miss the hewn log frame that is naked as ever.  If you come to a split in the road, you went too far.  I will be there all day tomorrow working.  I will also add my e-mail to my profile.  Not quite sure when this thing will go up, but perhaps this weekend.

thanks

[ohsoloco]

Cool, it's nice over there.  I was over that way back in the spring to pick up some logs.  Now, I've led some parades over mountains before in second gear pulling the trailer, but I actually had to downshift into FIRST gear to get up that mountain heading back towards Pine Grove Mills  :D

I'll be at work during the day tomorrow, so I wouldn't get over there much before dark.  Lemme know about this weekend, though.  Hoping to spend some time in the woods and at the mill, but it'll be a long weekend for a change  ;D

Oh, and about your question...I don't think the joint at the top would be a problem, but perhaps some collar ties should be added since the rafters would want to spread the outside walls apart.  Jim Rogers or someone with a lot more knowledge about the subject will chime in soon  ;)

[Jim_Rogers]

There are three ways or more to joint the rafters at the peak.
here are some of the ways:



One is to join them by just butting them and nailing them together. Not the best at all.
One way is to half lap them. Ok but still not the best.
One way is to create a open mortise and a tenon, called the tongue and fork joint.
Used most often.

Good luck.

Collar beams will help with outward thrust of the rafter feet on the plate, as mentioned.

Jim Rogers

[mark davidson]

In my area butting and nailing are most common, by far. I've rarely seen them fail unless the rest of the frame is falling apart.
Maybe that's the canadian climate? or just laziness....