I live on acreage, in a stick built house. I am planning to build a small, one room, mother-in-law type cottage on the back acreage.
I work in construction. I have a 4000cuft clay/dirt rifle berm from my basement excavation, to work from. my understanding is 50/50 moist clay to straw ratio. stomp/smash into clay, folding in on itself with a tarp until homogeneous. I have toms of wood ash from our heating stoves. should I mix that in? I know lime is often added. won't wood ash serve the same purpose as a cement additive?
I guess I'll just make a bunch of rectangle wood forms to press the cob into. I'll let them dry in the sun. I'll most likely just morter them with some form of clay from the berm as well.
for drainage purposes, I suppose I need to build some sort of raised foundation, at least 4" or so. can I just build up and pack clay, or do I need an actual concrete pour slab?
unsure of roof. leaning towards conventional rafter type, but haven't really researched options. also unsure what I will dry-in/weatherproof the roof with.
I have a basic idea of what I'm going to do, but am hoping that I can pick up some good ideas and suggestions, or random shit I did not think of.
It will have independent 120v AC, some form of running water, and an indoor toilet and shower.
I'm unsure how I will do the water source. I'm on a well, but I do not plan to connect it to the cottage. some sort of cistern or rainwater catchment. septic will be DIY from poly barrels & PVC or similar.
purpose is part fun/challenge, possible income (VRBO?) and part guest house for MIL or drunk friends who should not drive home.
You only need to make one brick form for each team you have working. Your mix should be dry enough it stays together after you lift the form, so you have awhile field of bricks drying after a while
use earth bags and the process becomes much more straight forward with no risk of making a bad cob mix. Fill a bag up, put it into place, pack it down, repeat.
>I work in construction.
Do you see a lot of cobb projects?
Zero.
Generally speaking, construction is construction.
I can frame, install electrical and solar, pipe fit, slab pour, brick lay, trim and cabinet carpentry.
when you know what goes into making a house, you can see the process to completion in your mind, even as the materials change.
saggy boobies
If you remove the topsoil and properly compact the ground, you can probably do fine without pouring a concrete slab.
Roof: Depends how rustic you're willing to go. A slant roof will be the easiest, and you could even use tree branches/limbs as the rafters. Corrugated metal/polycarbonate panels will be quick and easy, but if you really want to keep with the theme, you could make wooden shingles.
What do you mean by "independent 120v AC"?
As for water, if you want to go the rainwater route, I would have a basic filter before it goes into the tank, and then pump it through 2 reverse osmosis filters and a mineral cartridge into another tank. Rainwater is pretty nasty - it captures loads of dirt and pollutants on its way down, and then by the time it runs off your roof and into a tank, it's going to be filthy.
Septic is only needed for the toilet. The sink and shower can drain into a gray water sump. This will let you get away with a much smaller septic system.
I live in a cabin deep in the woods, so I can get away with anything. Depending on where you are, make sure that nobody is going to bother you about permits/inspections/etc.
120V AC:
120 volt standard/modern electrical wired from a solar system that will run totally separate from our house grid power, our solar system or our backup generator.
I want a standard, simple middle peak roof. I just built a "lean-to" single sided roof shed, and am already seeing some drawbacks to the single slope roof.
I lean towards modern roofing materials because I don't want leaks. most of my homestead builds have been 30# tar paper and comp shingles.
water catchment and filtration won't be that advanced. settling tank, bulk tank, screen filter, then in-line filter for shower and kitchen sink. I would probably have a specific kitchen tap with a "lifestraw" type/grade drinking filter. if someone needs more filtration for drinking, they (or i) can get a berky.
we live about 30 miles away from the nearest town. our area tends to leave people alone unless someone does blatant dangerous illegal thing like obvious shite tier romex jumpers or whatever. there are virtually no enforced building codes where we live.
>The sink and shower can drain into a gray water sump.
Mine are straight-piped about sixty feet way to a trench surrounded by thirsty plants. Very common in the southeast and very easy to clean out with a hose or pressure washer as required. I don't glue all the PVC so I can disconnect easily if needed years later.
I build and repair everything with an eye to the next time because there is always a next time if you live long enough and forethought is free.
house
hope there are no wolves about
>cob
>bricks
....but why? That defeats the whole purpose of cob
Making test blocks would be wise to refine your process. Mechanical mixing would speed the process and enable more structures if you like the result.
Building that test cottage is a damn good idea.
check out Compressed Earth Blocks/Bricks (CEB) or adobe... Usually when people say "cob" they don't mean bricks/blocks made of cob-like material.
You may want a little more dirt or sand in your mix depending on just how clayey your clay is. If it's mostly superfine particle slippery plastic clay, then you may have problems with it drying unevenly and cracking up a bit. The straw in adobe bricks not only adds reinforcement and strength, but it also aids in even drying.
Permies dot com has a bunch of good info about both CEB and cob construction.
not op but how heat stable, water, and wear resistant are they? could you build a firepit or bbq with them?
I've neer done that, but it's quite common for people to make large wood fired ovens with them. The water resistance is an issue; they usually coat them in a lime render, stucco, or something for exposed outdoor applications