The Forestry Forum is sponsored in part by:

iDRY Vacuum Kilns


Forestry Forum
Sponsored by:


TimberKing Sawmills



Toll Free 1-800-582-0470

LogRite Tools



Norwood Industries Inc.




Your source for Portable Sawmills, Edgers, Resaws, Sharpeners, Setters, Bandsaw Blades and Sawmill Parts

EZ Boardwalk Sawmills. More Saw For Less Money!

STIHLDealers.com sponsored by Northeast STIHL


Woodland Sawmills

Peterson Swingmills

 KASCO SharpTech WoodMaxx Blades

Turbosawmill

Sawmill Exchange

Michigan Firewood, your BRUTE FORCE Authorized Dealer

Baker Products

ECHO-Bearcat

iDRY Wood Lumber Vacuum Drying for everyon

Nyle Kiln Dry Systems

Chainsawr, The Worlds Largest Inventory of Chainsaw Parts

Smith Sawmill Service

Dynamic Green Products Inc.





Author Topic: telephone pole pier foundation  (Read 607 times)

0 Members and 1 Guest are viewing this topic.

Offline shinnlinger

  • Senior Member x2
  • *****
  • Posts: 2068
  • Location: Canaan NH
    • Share Post
telephone pole pier foundation
« on: May 21, 2020, 11:50:56 AM »
Hello,

Short question:  Are  there an "rules of thumb" for spacing on telephone pier fondation along the lines of this method of construction?  https://www.grit.com/community/tiny-house-setting-foundation-ze0z1407zjhar

This would be for a single story, 12x20 structure.  I'm thinking two 20 ft "rails" 9 ft apart that the floor joists would rest on (and cantilever over),  with 3 posts in that rail.  2 near the  ends and 1 in the middle.  6 posts in total.  Is this enough posts?  There is no local code, zoning or guidance.  I am also considering making the deck 20 ft wide so the house will have a 6ft deck on the front and creating three rails would be 8/9ft apart so the the outer  rails would be 18 ft apart with one in the middle 

Backstory if interested: My 17yo daughter is seriously interested in building a tiny house and I think that would be a fantastic project to do with her during these times with the grain of salt that it may never be finished as such or lived in and has just as much likely hood as being a chicken coop or storage shed if not just a tent platform.

As such, I am not willing to invest in a concrete pad or foundation.  Her chosen site has some slope, it is at the top of said slope, and I have a pile of telephone poles.  My plan is to do what excavation I can at the site with my FEL/rear blade on a 34 hp tractor, which likely won't be much more than scraping the top soil back and then boring holes with my 3 pt post hole digger  There is a reasonable chance of being able to to hit ledge so the piers can rest directly on that.  I do have some old foam panels I could insulate the ground with when back filling.

The slope and height of posts will allow some storage under the structure and allow for utilities,  spray foam or other insulation to be installed later, if it actually looks like anyone will live in it.  It would also allow for the possibility of house to be jacked up and put on a concrete foundation or moved.

We have the trees, the mill and the time, and even the metal roofing.  It won't be much in out of pocket expense until we get it closed in and the possibility of quality father/daughter time could be priceless.

Dave


Shinnlinger
Woodshop teacher, pasture raised chicken farmer
34 horse kubota L-2850, Turner Band Mill, '84 F-600,
living in self-built/milled timberframe home

Online Magicman

  • Senior Member x2
  • *****
  • Posts: 40338
  • Age: 77
  • Location: Brookhaven, MS
  • Gender: Male
  • A "Traveling Man"
    • Share Post
    • Knothole Sawmill
Re: telephone pole pier foundation
« Reply #1 on: May 21, 2020, 03:48:25 PM »
Remember that when you shorten a "utility" pole you have removed the treated portion and exposed the inner pith area which has minimal treatment at best.  This center untreated portion will rather quickly rot leaving you with nothing but the outside shell.
Knothole Sawmill, LLC     '98 Wood-Mizer LT40SuperHydraulic   WM Million BF Club Member   WM Pro Sawyer Network

Never allow your "need" to make money to exceed your "desire" to provide quality service.....The Magicman

Online doc henderson

  • Senior Member x2
  • *****
  • Posts: 5087
  • Age: 60
  • Location: Hutchinson, Ks
  • Gender: Male
  • Evil Prevails when Good Men Standby and Do Nothing
    • Share Post
Re: telephone pole pier foundation
« Reply #2 on: May 21, 2020, 04:18:28 PM »
for what you are building, the poles may be ok.  could consider the cardboard tubes filled with concrete for pillar/footing, reinforced with steel rebar, and the rails on top of those.  could even remove the deck and skid it somewhere in the future if needed.
timberking B 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor 12 volt tarp motor

Offline Hilltop366

  • Senior Member x2
  • *****
  • Posts: 2915
  • Location: Nova Scotia
  • Gender: Male
    • Share Post
Re: telephone pole pier foundation
« Reply #3 on: May 21, 2020, 05:27:43 PM »
I did much the same for a 20' x 20' backwoods cabin 20 years ago except we used untreated hackmatack for post, starting to replace some of the post now as they are getting rotten. 

For the 3 beams we used logs (guessing 10"-12") that I free hand chain saw flattened one side for the top and notched a flat spot on the bottom side where it sat on top of the 3 post. It has held up well except for the post.

I would make the deck separate from the floor joist, if the deck joist rot near the building it will carry under to the floor joist too.

Using 12'  2"x8" or (10" for less flex) SPF @ 16" oc  would give you a sturdy floor with 2 beams for the building and a third beam for the deck.

I have also used creosote rail ties for post for a shed before, they are 22 years old and still good.

Online Don P

  • Senior Member x2
  • *****
  • Posts: 7232
  • Location: Southwestern VA
  • Gender: Male
    • Share Post
    • Calculator Index
Re: telephone pole pier foundation
« Reply #4 on: May 21, 2020, 07:07:59 PM »
Quote
along the lines of this method of construction?  https://www.grit.com/community/tiny-house-setting-foundation-ze0z1407zjhar
What is bracing the poles?
If the poles are embedded in the walls and extend to the top plate of the walls, then the walls brace the posts. However you would have to isolate the creosote from the interior.
If you land on ledge that is a good footing, if in soil either a poured footing or treated blocking to create a wider footing will spread out the post load over more area. load/soil bearing capacity= footing area.
Quote
This would be for a single story, 12x20 structure.  I'm thinking two 20 ft "rails" 9 ft apart that the floor joists would rest on (and cantilever over),  with 3 posts in that rail.  2 near the  ends and 1 in the middle.  6 posts in total.  Is this enough posts?  There is no local code, zoning or guidance.  I am also considering making the deck 20 ft wide so the house will have a 6ft deck on the front and creating three rails would be 8/9ft apart so the the outer  rails would be 18 ft apart with one in the middle
You'll probably want the deck to be framed with treated and set a couple of inches below the floor. If there is a common beam supporting both, size it accordingly. I see many people forget the deck load on that beam. Flash and counterflash that area, it is a very common failure point. Porches are more durable than decks, they protect the building where the splash from a deck accelerates decay.
Ever notice that most of those kinds of magazine articles are written by the blind, leading the blind :D. Go to awc.org and download DCA6 from their publications tab. It is a deck construction guide but has some details that might work better.
A laborer works with his hands
A craftsman uses his brain and his hands
An artist uses his brain, his hands, and his heart

Offline Banjo picker

  • Senior Member x2
  • *****
  • Posts: 3254
  • Location: Iuka Ms
  • Gender: Male
    • Share Post
Re: telephone pole pier foundation
« Reply #5 on: May 22, 2020, 07:32:12 AM »
Remember that when you shorten a "utility" pole you have removed the treated portion and exposed the inner pith area which has minimal treatment at best.  This center untreated portion will rather quickly rot leaving you with nothing but the outside shell.


   And here is the proof....not that the MM needs backing up.🙂. Banjo
Never explain, your friends don't need it, and your enemies won't believe you any way.

Online Magicman

  • Senior Member x2
  • *****
  • Posts: 40338
  • Age: 77
  • Location: Brookhaven, MS
  • Gender: Male
  • A "Traveling Man"
    • Share Post
    • Knothole Sawmill
Re: telephone pole pier foundation
« Reply #6 on: May 22, 2020, 07:40:08 AM »
That is the top of the pole and the bottom that is in the ground is worse.  Folks put a cap over the tops to prevent center rot, but they can't see the bottom.
Knothole Sawmill, LLC     '98 Wood-Mizer LT40SuperHydraulic   WM Million BF Club Member   WM Pro Sawyer Network

Never allow your "need" to make money to exceed your "desire" to provide quality service.....The Magicman

Offline shinnlinger

  • Senior Member x2
  • *****
  • Posts: 2068
  • Location: Canaan NH
    • Share Post
Re: telephone pole pier foundation
« Reply #7 on: May 22, 2020, 11:02:03 AM »
THanks for the replies.  I arrived at the "deck" portion being a separate entity on my own just after I posted.  The points about deck/post rot are all valid.   At least half will be a porch but the whole thing can wait while we focus on the main structure.

Don P, that guide is fantastic if a bit overwhelming but a good resource for sure.  I have enough telephone poles around that I can cut the ends and put the treated side down,  It also looks like I will be able to get at least half of them directly on ledge and I will cross brace.  the posts will not continue above the deck

Its good to know Hilltop has done something similar and that components are replaceable if and when they fail.  

On a 20 ft "rail" if  the end posts are 17ft apart at the outside and the rail cantilevers over 1.5 ft on either side, can I get away with only one post in the middle?

Can I get away with two rails 9 ft apart on the outside edges? so that the joists cantilever over the edges 1.5 ft?

My feeling is I'm right at the edge of reasonable, but that it is reasonable.

Dave
Shinnlinger
Woodshop teacher, pasture raised chicken farmer
34 horse kubota L-2850, Turner Band Mill, '84 F-600,
living in self-built/milled timberframe home

Online Don P

  • Senior Member x2
  • *****
  • Posts: 7232
  • Location: Southwestern VA
  • Gender: Male
    • Share Post
    • Calculator Index
Re: telephone pole pier foundation
« Reply #8 on: May 22, 2020, 03:25:18 PM »
Support spacing depends mainly on your beams and the loads they support. The floor carries ~50psf total, the roof 15psf dead+ whatever your snow load is live. Then use the girder tables (chapter 6, or the beam calcs here. There is a cantilever chart in the floor chapter of the codebook R502.3.3(1);
https://codes.iccsafe.org/content/VRC2015P2/chapter-5-floors

Notice in both the deck guide and buried in the code that you cannot hang a deck from a cantilevered rim, basically it would be dangling on nails, so think carefully about canti on that side. Remember that whenever a joist crosses a beam, such as the canti joists over the inset girders, to block between joists over the girder, it is a tweak point, they want to lay over right there under load, waiting for the rim to restrain that is not a good idea.
A laborer works with his hands
A craftsman uses his brain and his hands
An artist uses his brain, his hands, and his heart

Offline shinnlinger

  • Senior Member x2
  • *****
  • Posts: 2068
  • Location: Canaan NH
    • Share Post
Re: telephone pole pier foundation
« Reply #9 on: May 22, 2020, 07:49:52 PM »
Thanks Don, 

I was thinking 2x10 joists for the the 12 ft span primarily so I can get enough insulation in there, so it looks like 2ft spacing would be ok.  

I had not thought about blocking the joists, but that makes sense, thank you for the tip.

the deck may never happen, but if it ever does, I figure I can create a third girder a few inches lower than the house and run 10 ft  2x8 PT under the house and catch the top of the inner girder that also runs on top of the new girder.  

Great points.

Dave
Shinnlinger
Woodshop teacher, pasture raised chicken farmer
34 horse kubota L-2850, Turner Band Mill, '84 F-600,
living in self-built/milled timberframe home


Share via delicious Share via digg Share via facebook Share via linkedin Share via pinterest Share via reddit Share via stumble Share via tumblr Share via twitter

xx
Helical Pier Foundation

Started by nick_m on Timber Framing/Log construction

0 Replies
317 Views
Last post July 27, 2020, 12:07:02 AM
by nick_m
xx
Pier foundation on boulders

Started by redlodge on Timber Framing/Log construction

22 Replies
2056 Views
Last post October 27, 2019, 08:56:01 PM
by ponderosae
xx
power poles for pier foundation???

Started by okie on Timber Framing/Log construction

29 Replies
13571 Views
Last post November 16, 2007, 09:25:24 AM
by ely
xx
Poured Pier Foundation for Small Log Cabin

Started by kantuckid on Timber Framing/Log construction

21 Replies
7189 Views
Last post January 10, 2018, 04:19:51 PM
by starmac
 


Powered by EzPortal