I am in the process of converting a small barn (25x32) into a workshop. The structure was built around 1870 and is mostly pine and hemlock with most upper level timber being 6x6. As part of a connected structure we could not jack it back to level without major issues with adjoining buildings so we took up the floor and mounted sistered dimensional plates and joists in a level plane.

Problem is that the (overhead)tie beam and a collection of iron rods that were just above head height before are now threatening to become even more annoying...

A word of explanation. The rafter plates are 6x6 with simple half lap pegged scarf joints. At some point a previous owner added several iron rods and turnbuckles in the center bay to prevent the frame from spreading. There is a rod (quite loose) from the tie beam to the ridge. They also added plates and yard-long eyebolts to reinforce the 6x6 tie beams. The tie beams enter the posts 8" below the rafter plate (leaving 2" of clear post before the tenon in plate direction). We have repaired posts and plates and provided real footings and support so that the structure is on solid ground and not likely to go anywhere.

I would propose to raise one tie beam to rafter plate height and use something like a Simpson MSTC strap tie on the top of the tie beam (and across the rafter plate and down onto the post) to provide a good tension connection and support the tie beam with a bolster or perhaps a ship's knee if I can find the material. I am concernd about a joinery connection at the post top/rafter plate as there is not much wood there as it is. It would be preferrable not to have to remove the roof (there is just room to accomplish this plan). The other 3 tie beams in the structure are or will be parts of wall structures and will be dealt with differently. As well, we will be augmenting the current roof framing (2x6 on 24" centers - and not at all plumb to boot )and providing a collar tie/ceiling member about half way up the roof.

What say you all? Does this sound reasonable or be there dragons about?

Andy,
You have provided your fix in the last para of your discussion. If there are tenons on the ends of the raised tie they must be removed to avoid cutting into the plate/post connection. I suggest you leave them in place by cutting them off with a recip saw prepatory to raising the tie to it's new altitude. The strap and bolster/ships knee support for the ends of the raised tie bring it all together. How do you propose to fasten the raised tie end support elements to the post ?

You didn't mention any braces in this tie. If they exist will new longer braces be able to use existing pockets in the tie/post ?

work safe, have fun

deralte

Emmet:

You are correct in assuming that the tenon will need to be cut. That would be singular becuase the north end is just a butt end seated in a housing on a 6x9 repair post and held in with more masses of iron rod. The ends will be supported by a mechanicaly fastened (with wooden plugs to cover offending hardware) bolster or ship's knee if I can come up with one. Should I need to use the bolster I will make up new braces at new angles and retrofit with wedged hardwood to foot the braces. Admittedly I am hoping to find some knee stock as that would be much nicer in the shop environment (and a lot more interesting).

As for the other tie beams, my plan is to use an idea I got from Herr Brungraber - Simpson Tension Ties on blocking that would get them to the appropriate heihgt. Fortunately they will then dissapear as the walls go up. I don't like all this metal stuff - wood is nicer - but sometimes you have to adapt to the situation at hand.