|
|
Replacing Post and Beam sills
Good Morning,
I'm replacing the sills on a small P&B barn. The barn has to be leveled and some new foundation work done.
Currently the structure sits on the original plinth stones which over time have settled into the earth. One corner of the barn has rotted down 5 inches past the 8 inch sill for a total of 13 inches down.
My questions are as follows:
1) What is the best proceedure here? My gut is to jack and level to 2 inches above final grade and then put in the foundation pilings followed by the sills.
2) How do I keep this building from racking out of square while jacking. Not to infer that it's square now but I hope to square it in the process.
Thanks for your help in advance,
Chris
|
|
Add Photo
Bookmarks: |
|
|
|
Replacing Post and Beam sills
If I was doing it, I would put in a secondary beam to carry the load from the sill inside of the existing sill. Then I would remove a post and do the foundation work. After the foundation was done, I would fit a new post followed by a new sill and then move on down the building. I am assuming that you want a new concrete footing under each post similar to the stone footing that you have now.
As you say, the building is not square now and leveling it out should not be a problem on the structure. I don't exactly understand jacking to 2" above grade. I would put in the sill a section at a time and splice it as necessary. In that way, you only need enough room to slide it into place. (less than 1/2 inch) Attachment can be done with modern hardare to make things easier.
|
|
Add Photo
Bookmarks: |
|
|
|
Replacing Post and Beam sills
Thanks for the input,
The 2 inches above grade is this....
The building is small 14 X 16 and the sills are all 1 piece.
All the upright posts are good except for 1 corner so I'm not replacing all the posts. Each horizontal sill beam 8x8 needs to be replaced as 1 unit. I think I'll need more room than 1/2 inch to get these into place.
I'm not going to rehang a floor in this building again. It's on a small slope and I'll fill it with 1/2 inch stone and pour a slap inside. I'll be using pressure treated for the sills.
I do plan to put concrete footings under each beam and restack the plinth stones under the rest of the sill.
Regards,
Chris
|
|
Add Photo
Bookmarks: |
|
|
|
Replacing Post and Beam sills
I guess that I had envisioned a larger structure. I agree that it might be difficult to slip in a 16' 8X8 with a half inch of clearance. I think that you should be able to lift the side of the building with three or four jacks and a good beam.
I do wonder if you could build the sill up out of 2X8s or a group of 2X6s and a 2X8 cap. You could then stagger the ends of the shorter pieces of lumber and have a joint.
Good Luck.
|
|
Add Photo
Bookmarks: |
|
|
|
Replacing Post and Beam sills
Just some thoughts, no real expertise here: I was happy to find some heavy turnbuckles in stock when I installed cable anchors for our construction trailer. The hardware-store owner said he kept them around because farmers used them to pull barns back to square. I really don't know if there'd be a use for that sort of idea here.
I have a new 10'x10' P&B where the sills are 2' above grade. If I had to get the weight off the sills, I'd try to get a trailer or steel frame from something under it and then jack up the frame but I have ground clearance.
I suspect that a building that's used to sitting that much out of level could use some remedial work on the wall stiffness etc. as well. Sounds like the posts plus stone didn't do the job over the long haul. I guess the original posts aren't on footings and the addition of footings should do the trick. It also sounds like the sills aren't going support the floor load when a slab is poured so maybe the original construction would be adequate. I don't know if there'd be any complications from a floating slab on stone on a slope that's inside the posts (if I have the idea right). It would prevent the use of cross braces on the posts, which you sometimes see in P&B structures on slopes.
|
|
Add Photo
Bookmarks: |
|
|
|
Replacing Post and Beam sills
Thanks Tom,
As far as having held up for the long haul... I guess it's hard to complain as the structure is around 150 years old. I had planned to use cables and turnbuckles to resquare the structure.
My approach to jacking is bolting 4x8x 24' across all side to tie the structure togehter and give me jacking points.
Regards,
Chris
|
|
Add Photo
Bookmarks: |
|
|
|
Replacing Post and Beam sills
Sounds like the project idea is well in hand. I'm just rambling on now. Most structures around here that are that old are log buildings built on top of logs that just lay on the ground. The just float on the frost and of course the floors aren't real level, but they do last longer than more modern structures built under code. Frost is a killer of foundations in unheated buildings. Piers or Alaska slab on grade is better but codes get in the way. The log on log idea won't work for a very tall building though.
I guess that when it's time to replace rotted logs it's done when the log will still support the building. Just jack up each end of a log, push a new one in beside a rotted one and push the old one out. I used to rent 40-acres of cedar bush down south that had an old cabin on it about the size of your barn. It was logs on logs construction and about 70-years old. It could have used some new logs though and I had to plane the bottom off the door to get in one spring. It's probably still standing. I guess it could be leveled by choosing logs of the right diameter and taper.
|
|
Add Photo
Bookmarks: |
|
|
|