• Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education skip experiences global resources cider press projects digital market permies.com private forums all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • Nicole Alderman
  • paul wheaton
  • Anne Miller
  • Pearl Sutton
  • Mike Haasl
  • Joylynn Hardesty
stewards:
  • r ranson
  • James Freyr
  • Burra Maluca
master gardeners:
  • Steve Thorn
  • Greg Martin
gardeners:
  • Ash Jackson
  • thomas rubino
  • Carla Burke

Microhome Addition

 
pollinator
Posts: 145
Location: South Central Kansas
94
kids purity fungi foraging medical herbs rocket stoves
  • Likes 2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I’m building a 12x27 addition to our 320 sq foot microhome to provide a bedroom, bathroom, and living area. This is just about the bare minimum for us to live through the cold winters while we build a new home.

My desire is to use site-harvested materials as much as possible. The current design is comprised of roundwood Eastern Red Cedar post and beam supporting a 1:12 living roof. I’m leveraging wafati technology, included post-in-ground, rebar pins, wide eaves, and umbrellas of billboard tarp. Walls, I plan to use straw ale and cob, as well as ERC siding. To support the walls I am digging a rubble trench with some sort of cap.

I have two major questions - the posts are going lower than the rubble trench - 9 out of 10 post holes stay very dry, while one seems to be more damp. Although I am providing drainage in the trench, I am concerned that moisture will follow the post hole and hasten deterioration of the post. The base of the trench and the posts is in dense clay subsoil. I have redundant structural support in the post and beam and strawbale cob, so I am not concerned about collapse, but I would like to do all I can to preserve the structure for the long haul.

My other question is if there are site-harvested materials that can be used in place of gravel or road base, both for the post hole drainage base, and for the earthen floor base layer. I have almost unlimited sand at my disposal, and a number of 100-year-old cinder blocks. Is there an alternative to gravel for a long-term, stable drainage base?

Other info: site is nearly flat, depending maybe 3 inches in the 27-foot span east-to-west. Addition is on the north side of original slab-on-grade construction. Top-soil is compacted sandy soil. We have a diverse woodlot and sawmill available. I am focusing on ERC because of its merits as a rot resistant wood, it’s ease of use, and the fact the we have many, many standing dead or recently fallen due to crowding.  My main priorities are low cost, self-built, lasting, and fast. I know that mix of factors doesn’t really exist (per fast:cheap:quality) but you get the idea. It has to be usable by November, and I can continue working on finishing detail and interior in the winter.

Any thoughts appreciated! I’ll post progress.
6A5B9F0F-9BB9-4F09-A988-BFCBB7311D3A.jpeg
Excavation with the tractor bucket
Excavation with the tractor bucket
B0FB2A61-AE72-481B-9040-A0798C0C5187.jpeg
Some small standing dead ERC coming out of the wood lot.
Some small standing dead ERC coming out of the wood lot.
99D4DCFD-1449-4FCB-A104-3E85225B7D73.jpeg
Example of where trench meets post hole in clay subsoil. This is the low point of the site.
Example of where trench meets post hole in clay subsoil. This is the low point of the site.
A3F0E032-EE4C-4161-BE16-BE40314D28EB.jpeg
Post hole. Upper 18 inches are soil, lower 18 inches are clay.
Post hole. Upper 18 inches are soil, lower 18 inches are clay.
 
pollinator
Posts: 3551
Location: Kansas Zone 6a
68
  • Likes 2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I am NOT a fan of putting wood in contact with the ground in most situations, especially clay, unless you have perfect drainage.  The easy answer is a concrete pier.  If you are opposed to concrete, you can cut stone posts to go in the ground or build a rubble trench and build it above grade.  At least for the troublesome one.  
 
pollinator
Posts: 1220
Location: Bendigo , Australia
71
dog gear plumbing earthworks bee building homestead
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I agree with R Scott.
I would concrete a steel stirrup and mount the posts to each stirrup.
The stirrups can be fabricated to suit the posts.
What floor are you going to have?
 
Beau Davidson
pollinator
Posts: 145
Location: South Central Kansas
94
kids purity fungi foraging medical herbs rocket stoves
  • Likes 2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Concrete piers were my original plan, until I got inspired by the bermshed etc. but I think you’re right, that this site is not a prime candidate for wood-in-ground. Piers it is!

I’m planning an earthen floor, either over gravel or road base, unless I discover another lower impact and local base layer alternative that promises good drainage.
 
John C Daley
pollinator
Posts: 1220
Location: Bendigo , Australia
71
dog gear plumbing earthworks bee building homestead
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
You may need to lower the floor area if an earthen floor is used, they need a fair bit of depth for the layers.
 
Beau Davidson
pollinator
Posts: 145
Location: South Central Kansas
94
kids purity fungi foraging medical herbs rocket stoves
  • Likes 2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

John C Daley wrote:You may need to lower the floor area if and earthen floor is used, they need a fair bit of depth for the layers.



I’m currently 14 inches below the floor of the existing structure. My plan is to build up 4 inches of gravel or other drainage/stabilizing media, then add 3 inches in subsequent layers of earthen floor, to ultimately arrive at a plane 7 inches lower that the original floor. I’ll incorporate some wooden threshold at the connecting doorway to step down. That’s the plan, at least.
 
John C Daley
pollinator
Posts: 1220
Location: Bendigo , Australia
71
dog gear plumbing earthworks bee building homestead
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
It does not look that deep!
Can you fabricate the stirrups yourself?Some hoop iron diagonally across the roof frame both ways should be a great help in creating lateral stability of the new posts.
 
Beau Davidson
pollinator
Posts: 145
Location: South Central Kansas
94
kids purity fungi foraging medical herbs rocket stoves
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

John C Daley wrote:It does not look that deep!
Can you fabricate the stirrups yourself?Some hoop iron diagonally across the roof frame both ways should be a great help in creating lateral stability of the new posts.




Hoop iron reinforcement is an interesting idea, new to me. After a brief internet search - Is there a strong advantage over timber cross-bracing? I suppose they are easier and quicker, for one. And can be embedded into the wall and hidden if placed properly. I have some learning to do.
 
John C Daley
pollinator
Posts: 1220
Location: Bendigo , Australia
71
dog gear plumbing earthworks bee building homestead
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
The flat metal stip lays flat and is quick to be installed.
We even can use a small device to tighten the strap, its 'U' shaped with a bolt and the 2 'U' shaped parts are pulled together by the bolt, very clever.
 
roses are red, violets are blue. Some poems rhyme and some are a tiny ad:
100th Issue of Permaculture Magazine - now FREE for a while
https://permies.com/goodies/45/pmag
reply
    Bookmark Topic Watch Topic
  • New Topic