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bwalak
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# Posted: 28 Feb 2014 19:21
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Hello I recently looked at a small cabin (12'x28') in Maine. The cabin was built in the '60s and uses telephone poles as a pier foundation (10 total). The cabin is built on a hill lengthwise (longest part is extending down over the hill). One end of the cabin was built on the ground and the other is about 3'-4' up on the piers.
The problem is that the end with the long piers has shifted over time and the piers at leaning slightly down hill (3"-4") the cabin is still level and the floor joists and frame are still solid. What is the easiest way to fix something like this??
Thanks!
Bill
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bldginsp
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# Posted: 28 Feb 2014 19:35
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You might be better off just stabilizing it as is, rather than trying to straighten out the poles. If you try to straighten them, you might do additional damage to the building. I'd think about digging around the base of the poles and pouring a substantial amount of concrete around them. The more the better, cause what you want to do is distribute the force of the pole as it tries to lean, onto as much dirt as you can.
Other than that I'd check the connections at the tops of the piers and improve as necessary or possible.
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turkeyhunter
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# Posted: 28 Feb 2014 19:58
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lots of places in Maine level camps.... they jack it up. Just to take pressure off of supports...put in these concrete lily pads.. ( that's what the locals call them...then use 6"x 6" PT wood posts on top of that...and then put the pressure/weight back on the wooden 6" x 6"'s.... on the high ends...they would put a another post/support near the existing one. Just get with a local and find a company and get a price. I looked at camp several years for sale...and it needed leveling, I got a estimate on having it done...it was $2000
BTW-what part of Maine??...I have one in the north Maine woods ...beautiful country up there!!!
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bwalak
Member
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# Posted: 28 Feb 2014 20:36
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Thanks guys this is really helpful! The camp is in the western mtns near rangeley
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turkeyhunter
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# Posted: 28 Feb 2014 21:13 - Edited by: turkeyhunter
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Quoting: bwalak Thanks guys this is really helpful! The camp is in the western mtns near rangeley
your welcome....was up in Rangeley last summer...very nice country...I am a click or 2 to the north and east of ya!!! Good luck with ya camp!!!!
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Truecabin
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# Posted: 1 Mar 2014 19:00
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id look it over real good make sure its not moving!
maybe add crossbraces to stop the movement
then trim and wrap the round poles with vertical boards that make it look like square poles so it doesnt look like its falling down
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MtnDon
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# Posted: 1 Mar 2014 23:53
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Quoting: bwalak The problem is that the end with the long piers has shifted over time
Do we know for sure that the piers were plumb to begin with?
What about trees close by on the slope. Are they straight plumb or are there curved butts like happens when the hillside is moving very slowly and the trees are compensating? Called pistol butt. I'd stay away from that.
Actually I'd stay completely away from that cabin unless you got an favorable engineers report that there is no problem or an estimate you can live with on the cost to correct. Correcting foundation problems can be hazardous to your well being.
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MtnDon
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# Posted: 2 Mar 2014 00:01 - Edited by: MtnDon
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Quoting: turkeyhunter lots of places in Maine level camps....
The fact that there are lots of contractors specializing in correcting pier foundation is maybe a hint that piers are not the best foundation to be used. Just a thought.
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bldginsp
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# Posted: 2 Mar 2014 07:44
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Or it is a commentary on the methods used to implement them.
What it always boils down to is, more square footage for the dollar, rather than more dollars per square foot. Can't blame people, but then you see the cost of the consequences.
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turkeyhunter
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# Posted: 2 Mar 2014 08:34 - Edited by: turkeyhunter
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Quoting: MtnDon The fact that there are lots of contractors specializing in correcting pier foundation is maybe a hint that piers are not the best foundation to be used. Just a thought
AND THE REASON FOR THIS IS
there are thousands of old camps built in Maine...hunting camps...lake camps...river camps....most built with what they HAD on site or what they could put there hands on at the time!!!! ...and quess what...they have stood up over a 100 years...WOW!!! how did they do that with a engineer's report...approval etc...just wow ...I been to lots of old hunting camp where the piers were a flack rock and a piece of hemlock firewood stood on it in and they built on it...quess what ~~~still standing....
BUT when ya get a lot of flatlanders MASS/CONN/NY/RI /ETC..lol
who BUY camps and they want to correct the piers because it does not look safe..or good to the eye...LOT OF PLACES....will be glad to do that work for ya..the locals need the $$$...and they make it look better...and who knows it could stayed like that ~~ say another 100 years with no problem...so that's your answer!!!!!!!!!!!!!!!!!!!!!!!!
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Don_P
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# Posted: 2 Mar 2014 10:02
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Agreed, since there aren't prescriptive pier codes individuals are left to their own devices some folks have a better understanding of the forces or potential forces at work than others. Back in my older codebooks we did have some prescriptions for bracing coastal piers that could be applied to other situations. Those sections have been removed and replaced by the current stipulation that all pier foundations be engineered, for better or worse. Unfortunately this has led to a lack of any guidance and since we don't have uniform code enforcement it has left many people without any reference and without someone to say "that isn't real bright". Generally the older methods required bracing and much better bracing than I see being done currently.
In the case of these piers there is one bit of information I can think of that might help while looking at them. Figure out the vertical load on each pier. If the pier is vertical that load travels straight down the pier and is delivered to its' footing. As the pier tips some portion of that load travels down the axis of the pier and some portion of the load travels horizontally and is resisted by the soil in keeping the pier from toppling. The way to figure that horizontal load is cosine (theta). For instance cos(90), a plumb pier, = 0 the load is entirely vertical. cos(89), 1 degree out of plumb = .017, 2% of the load is trying to push it over. cos(80), 10 degrees out of plumb,=17% of the load is pushing it over. cos (70)=34%, cos(60)=50%. By now it's definitely on the ground. These problems tend to be self feeding, it takes very little bracing to hold something vertical. As the load shifts to delivering more horizontal load the soil yields, the force increases, causing more yield, raising the horizontal load, etc, until a point is reached where the load overcomes the resistance very fast and Whump, it topples.
That is the problem with trying to dig around a pier that is already leaning. While you are removing the resistance from the one pier the horizontal load is increasing on the surrounding piers, they go into motion. You pour mud around the repair pier but it takes some compression of the new repair in the soil before it begins to offer resistance, more motion. Go to the next pier and undermine it, more motion. The situation can get away from you before you know what hit you. Shoring the structure while this is being done is a very good idea, don't leave the finished repaired pier out of plumb... and brace it securely when done.
What I left out of that description is the trigger that usually springs this deadfall trap, wind, there is a big sail on a long heavy lever arm acting above the pier. This should begin to sound like an engineer's playground.
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Martian
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# Posted: 2 Mar 2014 10:28 - Edited by: Martian
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If I were to devise a fix for this, it would be to run appropriate sized diagonals from the top of each pier to a point below grade on the uphill side of the next one. Assuming the cabin isn't pulling apart, all the piers are moving at the same rate; so all the piers would need the diagonals. Add a deadman downhill from the last pier to brace that diagonal.
I would want to know how deep the piers are set so that the low end of the diagonal could be placed at or slightly below the pivot point of the soil resistance.
If all the soil is moving, the cabin should be stabilized even though the views are slowly changing. 
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old243
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# Posted: 2 Mar 2014 10:31
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You might also look at the drainage , Is there evestrough to get rid of the water, around the piers . Or is the soil saturated in wet times . Or is there a sidehill soak that might be affecting drainage.old243
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Truecabin
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# Posted: 2 Mar 2014 16:53
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agree with turkey if its standing for 50 years and not moving fast maybe its ok
agree with martian brace it so the load on the piers become vertical again
agree with truecabin to wrap the poles so they look vertical again
agree with old243 look for ways to keep the hill draining maybe dig a well on hillside and watch it
these kind of properties scare away a lot of buyers
there is a reduced price, maybe a buyer who has ability to deal with it can come out OK
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