Mother Nature really has nothing better to do. Gravity always pulls things down, wind likes to knock things over, and water tends to get everywhere we try to keep it out of...

Some interesting reading I just picked up: The World Without Us

And a cute little video based on the book:
YouTube Video Link

Gents,

I am 1/2 way across the state on another job right now. I'll endeavor to get your requested pics and additional measurements asap. I appreciate your input.

My original post did reference these two barns with their specific structural issues in mind but I am also trying to gather ideas in general about dealing with outward thrust when the joinery is already in place. Your posts thus far have given me some great ideas and have helped me expand the brainstorming that I do before getting down to the engineering.

Working alone, as I do in SW Michigan, it is wonderful to have this space to share ideas.

Thanks,

Shawn

Hey Shawn:

Glad to know we're providing some insights. And glad to hear we haven't scared you off!

I also like having this space to share ideas. It's interesting to explore what's happening w/ these old structures as the decades and centuries go by. Reports like yours help broaden everyone's knowledge base. In this way, the Forum can enlist a growing number of "scouts" that can be drawn upon for historic / regional TF discussions before more of these buildings are lost to disrepair and the real estate cycle.

In your case, I think Tim's roofing suggestions are good elements to consider. If only owning a barn (re-roofing) wasn't so expensive they'd all be fairing better...

Looking forward to seeing more of these barns.

And don't take any of our advice too seriously, OK?!

I like Will's idea of steel straps. Pull it all together and button it up. Might almost be worth investing in a truck mounted drill press and small forge to bend the puppy into a nice outside post/ plate to tie beam unit on site. If only to omit lags/ threw bolts and use wood pegs. Cancel that order. ha!

Shawn -

Are you familiar with the Michigan Barn Preservation Network?

Might not be timber frame specific information on there... but could be a good resource.

I posted to a similar list when I lived in Ohio - the Ohio State Ag extension (if I remember correctly) had a similar sounding group.

-Mike

Yep, I have read up on MBPN and have met Steve Stier who is a wonderful man, a talented TF preservationist, involved in the organization of MBPN, and the man who started the Michigan Barn Survey.

I plotted a map showing all the folks listed by MBPN as involved in restoration. It can be found at http://maps.google.com/maps/ms?ie=UTF8&hl=en&msa=0&ll=44.079693,-84.847412&spn=3.993443,8.481445&t=h&z=7&msid=116553168999666214092.00046c3c8e63586d6336b

OK, back to the barns I mentioned earlier. Today, I'll post photos from BARN 1. BARN 2 later.

Posts and ties are 8x8 mixed hardwood
Tie is dropped about 20-21 inches from the bottom of the plate
Barn is 24'x40' with bents spaced approximately 10' apart
Two layers of roofing (wood shingles covered with corrugated steel) - the farmer is firmly against removing the roof and replacing it.
Foundation is 20 years old at the most. The, presumably, rotten posts and sills were removed and replaced with hollow concrete block perimeter and a monolithic slab floor. The perimeter posts are now 24-30 inches shorter than the posts in the center of bents 2 and 3. I say presumably because the current owner does not have the history though she does know that the previous owner, who replaced the sills with concrete, housed hogs in the barn.
Clearly the last 7 feet or so of the tie shown in close up needs replaced. When I knocked on it it alternatively sounded wet or hollow. The rest of the timbers seem to be without this kind of significant rot.

[img]http://picasaweb.google.com/lh/photo/Jo4AJja7gD1Dbnu3zkG1ow?feat=directlink[/img]


[img]http://picasaweb.google.com/lh/photo/ibSdtEjD1rKOGYth7V0-hQ?feat=directlink[/img]


[img]http://picasaweb.google.com/lh/photo/mhvIz62o5vVahWpmqQ6tPw?feat=directlink[/img]

Hope these links/images work. I am using Google's Picasa. Anyone else have experience with Picasa and the TFG Forums?

Ok, so now with images and more structural details, any more suggestions about limiting the outward thrust at bents 2 and 3?

-Shawn

to use picassa and the forum, go to your picassa image and look for the 'link to this photo' option on the right. select the resolution and be sure to check the boxes to hide the album link or whatever. then select and copy the text in the box, come back to the forum, press the image button and paste in the text.

Slick, thanks for the tip Mike! I imagine there is a similar way to drop in that google custom map too.


One of you gentlemen suggested a wooden solution might be to support the ridge with an additional post. Given that the barn has posts through its centerline that seems a wise potential solution. This barn is not utilizing the "loft"space and so such a solution would not be obstructive.


This is actually a corner post without pegs that seems to be withdrawing as well. In fact none of the braces have pegs in this barn either (nor peg holes). New pegs in all the empty holes would also help. When I examined this barn I did not find any evidence of a wedged dovetail or wedge of any kind. I did, however, stick my fingers in all the empty peg holes to feel for tenon relish and found solid wood throughout.


This section will need a scarfed replacement. The water damage was from a leak in the original roof that has been since covered by the steel roof.


I have plenty of truck straps to take up some of the thrust while working on the structure and a few bottle jacks to lift the ridge (potentially). I think replacing the existing steel cable with a new one without rust could be worked into the budget. It seems to me that placing the cable up at the plate instead of the post would provide more thrust resistance where it is needed. Any suggestions on how to keep the wood from getting crushed/marred/strangled by the cable?

Shawn, you seem to have left out in previous descriptions the canted queens, I may have missed it though. Are the rafters one piece or two, breaking on the purlin? At only 24' I am guessing full length. They are reduced at the purlin. If there is a break/segmented rafter has the rafter pulled apart at the break, right over the purlin? Just something that may be noteworthy.

The queen system should be assisting with holding back the thrust of the rafters, there is the strut backing the queen post up, but if the ends of the ties are compromised, like the one in the bottom picture, the strut has no base and I can see it drifting. How many ties have rotted, just the one? Do the others show withdrawal of the tenon, other than the one with the missing pegs? It would be my suspicion that the repair of 20 years ago only sured up the building, leaving it distorted, did they correct the foundation in a way that brought the building true again? Check all the lower wall girts to see that they are all in the same plane, a bench mark, using a water level or laser transit.

Once back together that corner post with the missing pegs, begs for 3 new pegs.

Tim

do you have any details of the history?

it is interesting that there is a mix of sawn and hewn pieces... i've seen this before - but usually the smaller sticks would be sawn - braces, struts, maybe rafters, etc... but this looks like that corner post is sawn. has that been replaced previosly? are the center posts sawn or hewn?