I built a straw-clay house that mostly had dimensional lumber trusses (hidden in the walls) with some exposed timber framing.
1. I think rectangular timbers would be easiest to build - especially since you want to conceal them. Also you can take advantage of smaller lumber with concealed ladder trusses. You attach the temporary forms to the trusses when packing the straw-clay.
2. Concealed framing is no problem - in some ways it is easier. You do need to prepare the joints more where the plaster covers the timber/straw-clay joint, but that is pretty simple. The wood will be fine as long as there is a good roof, foundation, etc.
3. The timbers we used were fresh felled trees (forests were closed due to fire hazard until we absolutely needed the timbers). There was more twisting and checking of the wood, but it turned out fine. The species of wood affects how timbers behave when green, but it generally works.
Even a stiff wood floor flexes. This will make earthen materials crack like crazy and likely spall off. It might work if the material is fully saturated with oil and fully bonded to the floor boards, but it would be a serious challenge.
I would definitely try test pieces on plywood before committing to a floor.
In my experience lime plaster over earthenplaster works fine if there is good tooth to the earthen plaster (can't be crumbly or too smooth).
Mixing lime into earthen plaster is trickier. Too much lime makes the clay a less effective binder. I have found up to 10% lime (percentage of binder by volume) is generally o.k.
You could probably mix lime into the slip for light clay straw. I have never done this. I haven't had any issues with insects or other critters in the clay straw. You may be trying to solve a non-existent problem with this. Personally, I wouldn't do it, but It would probably work.
Type S lime is fine. For plaster I like to have it soaking for weeks before use, but that isn't necessary. Protect yourself when mixing lime.
I realize this is probably a little late to resolve your issue...
The driller was on the right track with the gravel pack but the material size was wrong. The slot size of the well screen should be based on the sediment size the well is installed in. Then the filter pack particle size is based on the screen size and aquifer sediment size.
You mentioned 10,000 slot screen. I think you are talking about ten thousandths of an inch slot (0.010") which is about the smallest slot size used in wells. So that was appropriate. However, the filter pack size sounds like it was way too big. The filter pack should be the smallest size that has about 95% or more retained by the screen. So a 0.010" slot screen with very fine sand or silt aquifer would have a filter pack mesh size of 20/40 (see attached chart). That should hold back the fine aquifer material and still let water through. The well driller will still need to develop the well to clear out the fines and get the filter pack as clean as possible.
This is pretty basic well design. Though some drillers only know 'the way they have always done it'. I've run into drillers who place pea gravel as a filter pack no matter what the aquifer sediment size is. Not only does that mean you may be pumping sand forever, it can create voids that can put assymetric force on the screen and collapse it.
For what it is worth, I am a geologist/hydrologist and routinely design wells.
5 feet of water column is not much to exchange heat with. My guess is it would not be worth the equipment to plumb it etc.
My parents have a closed-loop geothermal system with three 200 foot wells. It works well for the most part. They had one cold winter where the glycol going through the system actually froze the groundwater adjacent to all three wells.
The heat capacity of a shallow well wouldn't get you that much heat. Especially if the well isn't pumped. You get more heat if the water is pumped regularly
It could be done. I think you would want areas at different stages of completion so people could work all stages. Otherwise there is a significant amount of time between layers drying and oil applications curing.
12 inches is not a firm maximum wall thickness. You can go thicker - particularly in drier climates. A common rule of thumb is that the walls dry about one inch per week (6 weeks for a 12" wall). However, I think our 12" walls dried in 3-4 weeks. If you have decent drying conditions you could go thicker than 12" if you wanted.
Another thing is that you can change the mix to get more insulation value or more mass. Typically, people make a lighter mix for the north walls and heavier for the sunny sides. Also, the light clay straw walls perform better than the R-value would indicate due to the effect of the thermal mass in the walls.
I would recommend against layering the walls with dry straw in the middle. First, it would be a pain to install with any consistency. Second you would be making planes of weakness parallel to the wall surface. You could easily get sections that spall off. One of the beauties of light clay straw is that the material makes cohesive, uniform density walls. Layering the walls would disrupt the cohesiveness of the walls. You are better off making the walls thicker or using a lighter mix.
Maybe if you ran the leaves and vines through a serious chipper/shredder then dried it partially before bailing. I don't think you could get uniform density bales without chopping it in some way. it would be a great use if it worked.
Jarret Hynd wrote: I've never been able to get any to propagate from cuttings, though I'm trying direct seed this year and hoping for some decent results.
Both you and Thomas mentioned poor luck with cuttings. This is weird. I rooted a dozen softwood cuttings this summer and they took root faster than cottonwood with no failures. I used a peat moss/vermiculite mix with a IBA hormone dip.
The problem I have with Goji's is leaf drop from powdery mildew. I think my mistake was wetting the foliage the few times I watered them.
The saline water will harm plumbing, especially copper, brass or steel components. PVC or PEX would be best for corrosion, but you often have brass components with PEX. Washing machines would probably be harmed as well. I suspect the metal components in the washer would fail prematurely (solenoids, pumps components, etc.) It would probably also harm the water heater which consists mostly of metal components.
Determining how corrosive the water will be is somewhat difficult. You need more information on the water chemistry (and temperature). The commonly used calculations for determining how corrosive your water will be are the Langelier Saturation Index and Ryznar Stability Index. Both of these assume low chloride concentrations typically found in potable water systems. There are probably calculations for brackish water, I just have never used them or looked for them.
If your bore hole is larger than the drive point (you aren't actually driving the screen into the sediment), it is a good idea to place clean silica sand around the screen and put a bentonite seal above the sand pack before back filling the hole.
Other screens you could use include slotted PVC and steel pipe screens, Wire-wrapped screens (except drive point wire-wrapped) are more for larger wells and are quite expensive. A good pipe supply company near you either has slotted screen or could get it for you. You can slot pipe with a hack saw or chop saw. This generally makes slots that are wide and allow sediment into the well. And most people get tired of cutting slots and don't make enough. If you were to slot your own pipe, wrap the outside of the pipe with a decent filter fabric.
I would strongly recommend against packing cloth around an open pipe as you suggested.
We used a resin based hardwood floor finish over the (cured) linseed oil sealed floor. It works well - no stickiness. I don't know if it would have been sticky - we were going to use the hardwood floor finish regardless.
Our hydronic tubes are about 3 inches below the floor surface spaced 9 inches apart and are heated by a solar thermal system. Even though the house is only about 800 square feet, there are three zones (& thermostats). The bathroom/foyer (north side) are set the warmest, kitchen/living room less so, the bedroom zone we rarely heat. We really like how it works. It takes about 3-4 cloudy/cold days in a row before we have to build a fire in the woodstove.
Your plan sounds pretty good. The gravel layer is important. Use some landscape fabric on top of the gravel and perlite layers to keep fines from sifting down into the gravel/perlite. If fines gradually sift into the gravel, the floor can become unstable and crack, etc. also the pore space in the gravel is important for moisture control (capillary break).
Instead of gravel and perlite, I used 1/2" screened pumice (14" at the perimeter, 9" in the middle)(no expansive soils). If pumice is available, you might want to consider it instead of perlite. I think it probably provides a more stable base.
My guess is removing another foot of soil probably wouldn't accomplish much. Normally expansive soils that are problems are fairly thick. Dig a hole and see what the soils look like.
We ran into a similar situation when building our house. There was a large fire ant hill in the middle of the house location. I dug in a 4 pound box of borax into the ant hill its self with a backhoe (the colony went about 5 feet deep). Then before placing the gravel for the floor base, I dusted the ground with another two boxes of borax (over about 700 square feet). So far there haven't been any intruders through the floor. I don't think the two boxes dusted over the floor area was excessive. The ant hill area was well dusted but most of the rest of the floor barely had any. If I had to do it over again, I would use another box or two. That said - there haven't been any issues.
I think it would be best to use full thickness bricks which would require a stable shelf/foundation to support them. As you indicated adhering veneer to lime mortar/plaster would have a weak bond. Are the bale walls already constructed and plastered?
One option for the veneer would be to cut back into the plaster/bales as needed and install some cement tile backer board. The backer board can be screwed into framing lumber and wood dowels can be driven into the bales through holes drilled into the backer board. Once the backer board in installed you could use fortified tile mortar to adhere the brick veneer slices.
Bethany Dutch wrote:So - I've looked at that website and so really what you're able to do is directly use the water that comes OUT of your septic for irrigation? Their website says everything literally is fully digested - have you found that to be the case?
Yes, we use the water coming out of the tank for irrigation. It goes into a pump tank that alternately pumps to three irrigation zones. There is a fourth, gravity drain zone in case there is a prolonged power outage, pump failure, or temps are below 0 F.
So far, we have been using the system for five years and it has been working as advertised. The effluent water is clear with a faint odor (not at all like normal septic effluent) and there is no measurable sludge in the tank (very end of dipstick showed a little). The system greatly reduces biochemical oxygen demand but does not reduce nitrates by much at all because there is no anoxic zone/process. Not reducing nitrates is no big deal because the plants use it readily. Our well water is somewhat salty so we are careful not to use any powdered detergents, borax, etc. that would make the treated irrigation water even saltier. If we wash anything with borax, etc. that water gets dumped on the gravel driveway.
I think someone could create a do-it-yourself version of a treatment system like this. Since we had a building permit and some bank loans, we had to go with a permitable system.
Zee Swartz wrote:... I must know: is it possible to paint on an earthen floor with, say, kaolin paint before sealing and expect the design to hold up? ...
Anyone done anything like this with earthen floors?
I attempted something similar and can suggest how not to do it. The floor mix I used in the first room I did had too much clay in it and had shrinkage cracks. I filled the cracks with a mix of kaolin and fine, white silica sand. My thought was the cracks filled with white material would contrast nicely and show the cracking pattern. However, sealing with linseed oil significantly darkens all colors and made the white filler somewhat translucent (and dark). The color difference was muted by sealing and made it barely noticeable.
Based on that experience, I think it would be best to do the stenciling after the floor has been fully sealed. This would help maintain the contrast. It would be more durable to do the stenciling before doing a final floor finish (I use a hardwood floor finish on top of the sealed and cured earthen floors). However, this will affect the color of the stencil. You could do the stencil last, but it will wear (paint would be much better than kaolin alis if done last).
There are also advanced treatment options you can do in septic tanks so you can discharge the effluent as irrigation water. We have this system in ours: http://www.sludgehammer.net/ There are pluses and minuses to these sort of systems. Basically what lead us in this direction is that doing an advanced treatment septic system was cost comparable to doing greywater distribution and (manufactured) composting toilets with less maintenance in the long run.
More to your question... You can compost septic effluent and sludge. For my job, I have set up industrial composting operations for municipal wastewater treatment plants. This could be done on a residential level (maybe not legally). Though it could be unpleasant and a pain to do (directly handling anaerobic effluent and sludge). With the industrial composting operations, the material mix is balanced after developing recipes based on available feed stocks (carbon-rich, fluffing material) and the compost is turned to maintain at least thirty days at high temperature (~150 F) for pathogen reduction. Usually, the material is composted further without the careful temperature monitoring and frequent turning.
I think by making a septic tank aerobic instead of anaerobic, it would make composting easier and more pleasant. Keeping the septic tank aerobic breaks down a lot more of the waste material and greatly reduces odors. Also, the amount of sludge generated by an aerobic system is very small - so you would be mostly dealing with the careful use of the water.
Putting the posts directly in the ground is generally a bad idea. You can do it using rot resistant or treated posts in areas with well drained soil and deep water table. Even then, I would avoid doing it if you expect the structure to last. Besides rot, there is the potential for termites and/or differential settling causing trouble. It just isn't worth going cheap on the foundation of a house you are going to put that much work and money into.
Anchoring the posts to concrete pillars or steel piles would be a different story.
With a rubble trench foundation, you would normally put anchor bolts in the bond beam and have the posts terminate on the beam with post bases, etc.
We used wool insulation to pack around window frames and other nooks and crannies. Basically places where you would use polyurethane foam ('Great Stuff') in conventional construction. It works really well for that use.
We ordered from Oregon Shepard. There is also Good Shepard Wool and maybe others.
It would probably work well as your primary insulation. As you mentioned it is expensive.
Don Elbourne wrote:
My main question is: If I cap this, or install a spigot, will it lose its prime and stop flowing?
No, flowing artesian wells will not stop flowing from being capped. They do stop flowing from lower hydraulic head in the aquifer usually caused by lower recharge into the aquifer or increased withdrawals from the aquifer. If you put a pressure gauge on the capped well you can see how much the head changes over time.
I haven't tried this but I use bentonite in my work frequently.
Bentonite swells with hydration to a crazy degree. I think it could easily swell into the sand/gravel of the wicking bed over time. I would put sheet plastic over the bentonite. It doesn't have to be water tight, just continuous enough to prevent wholesale swelling of the bentonite. Somewhat similar to a geosynthetic clay liner (bentonite perforated plastic quilt)
I use chicken wire under the barrier to keep out gophers as you suggest. It has worked so far. Though I don't know if any have tried to burrow through.
Like many things, it depends. The good news is earthen floors can be quite durable. However, it depends on the mix of floor material and how you seal/finish it. Easily damaged earthen floors usually have too little sand (too much clay) or weren't sealed and finished enough.
We have earthen floors with radiant heat in our house in all rooms except the bathroom and foyer. The floor was sealed with linseed oil (with citrus thinner) and then two coats of a hardwood floor finish.
We wet mop the floor frequently (it does not absorb any water). Greasy spills are no problem, though you don't want to leave a serious degreaser on the floor for too long since it will damage the hardwood finish. A scrub brush would be o.k. as long as it has plastic or natural fiber bristles. A metal wire brush would damage it. Dog nails or normal shoes don't scratch. Though boots with sand/gravel stuck in the treads will scratch. Furniture with small, hard feet may make small dents. Also, I dropped a dutch oven that made a small dent. We have rugs under the rolling office chair and living room furniture to prevent wear.
Substituting slag for sand will probably work fine. Any aggregate that doesn't expand or contract significantly through wet/dry, hot/cold changes should work. Some slags will expand over time through chemical changes caused by devitrification. There probably won't be enough moisture (or time) for significant devitrification. I'm not sure about the ferric oxide. However, if you have access to a dry creek bed for the ferric oxide - can't you collect sand from the creek bed and not have to make substitutions for sand?
I don't think the magnets will work simply embedded in the cob. Cob has a low tensile strength. The tension created by the magnet and food-filled pan would likely pull the magnet through the cob or if there is enough cob between them to prevent break-out, the magnetic field wouldn't be strong enough to suspend the pan. You could attach the magnet to an armature built into the cob, but if there is an armature why not hang a hook from it?
What type of mortar was used for the foundation? Normally, I would use a similar type as the underlying stonework. Usually, that would be some sort of lime/cement mortar. The ratio of lime to cement dictates the compressive strength and adhesive properties. More lime gives better adhesion but lower compressive strength, higher cement gives higher compressive strength but lower adhesion. Adhesion is more an issue with the flat rock caps since the irregular surface of the underlying stonework resists lateral movement. I would probably use a high lime mix like 1 part lime, 1 part cement, to six parts sand. or 1/2 part lime, 1 1/2 parts cement to six parts sand. Your foundation walls likely have a large area - so compressive strength shouldn't be an issue.
You can improve the adhesion of the stone cap by cutting shallow grooves in the bottom surface with a diamond blade on an angle grinder. Also, I normally paint the underside of the cap stones with a lime/cement slurry (toothpaste consistency or a little thinner) (without sand) before placing the stone pieces on the mortar bed. The lime/cement slurry on the stone pieces improves the adhesion significantly. I would probably go with sandstone over slate. Sandstone is easier to work and will have better adhesion. The cap stones need to extend past the bales if you want to see them after plastering the bales. It would probably be a good idea to install pins or anchors that go into the foundation and bale wall. The pins could go between the cap stone pieces or you could drill holes through the cap stones. The pins will help prevent lateral movement of the bale wall on the now flat foundation wall.
A concrete bond beam would also work and it makes it easier to install pins or anchors. If the bond beam is the same width as the bales, it will get covered by the plaster and you won't see it.
There is a units issue here. Watts of electricity is not equal to watts of optical power. Watts of optical power has a luminosity function that works to covert emitted light into watts. I think using watts for optical power is misleading - this article is a perfect example. The laws of thermodynamics still apply, it isn't a spectacular discovery - its inappropriate comparison of unequal units. The article does support the very good efficiency of LEDs, but does it in a misleading way.
While it isn't ideal to use green wood, I wouldn't worry too much about it.
When we were building our house, the forests in the area were closed to logging due to wildfires. The forests finally opened right when we needed the timbers so we had to use wet wood. The visually exposed connections were mortise and tennon and the hidden connections were plates and screws. The timbers did shrink and check somewhat but didn't seem to create loose connections. In fact the slight twisting of the timbers during drying seemed to lock the mortises and mechanical fasters tighter. Not all woods twist when drying however. With infill walls you can't really re-tighten screws later if the bales are in the way. I would just do your best on the framing, use more than the minimum of fasteners, and plan to stuff the spaces between bales and alongside posts/beams with cob before plastering.
Also, the finish plaster is most likely to crack over the drying timbers. You can work reinforcing into the first plaster layers that will help prevent this. I often use burlap fabric soaked in clay slip to bridge these areas. Even with dry lumber it helps.
You may want to wait under construction is nearly completed before doing the last layer or two of floor and oiling it. The floor will take some damage during construction - so the longer you can wait to do the final finishes the better. Also, if you do the base and intermediate layers well before the final finish layer, you don't have to worry about drying so much.
Once the floor is finished (and oils/finishes cured) cover it with cardboard or drop cloths until the trim work, painting, etc. is done.
You could drill holes in the floor (in places that you won't see the small patches later) and use a soil moisture meter. You would watch the moisture levels decrease until they stay the same (and low) for a few days. You could also put a hygrometer on the floor and outside. If the humidity is consistently the same on the floor as outside - it is probably dry. A drying floor will make the indoor air more humid especially immediately next to the floor.
There can still be a significant amount of moisture in the floor after the color lightens and appears to be dry - so the color change is probably not the best indicator.
However, I've never measured moisture in the floors I've done. How quickly and how dry the floor gets depends on the relative humidity, temperature, ventilation, mix of the floor material, and how thick the layers were laid down. My advice would be to wait until humidity is the same inside as out, then wait a little longer for good measure.
I plastered our bathroom with lime plaster (Tadelakt) over gypsum board. The method I used was to apply thin-set tile mortar with a 3/16" v-notch trowel over the drywall to create tooth for the plaster to grab onto (wipe the drywall with a damp cloth first to remove dust). The v-notch troweling was done horizontally to give the most advantage against gravity when troweling the plaster. The plaster was applied over the thin-set mortar after it cured for at least a day. Its been several years since the installation and there haven't been any cracks or spalling.
For earthen plaster over drywall, I brush on a wheat paste and sand mix before plastering.
First, the iridescent sheen on the wetlands is probably naturally occurring. It is very common. If you stir it with a stick the normal wetland sheen will tend to break up more than get pulled and mixed together. Petroleum product sheen usually mixes much easier and stays more liquid.
For the soil there are many options. You could look at excavating the worst of it and disposing. I work on large spill sites and often do this. Usually the cost is $20-40/ton at land farms or landfills near me, not including transport if hired-out. The cost may be different where you are and for smaller quantities, etc. Disposing normally requires a lab analysis of the soil to verify it is non-hazardous by the regs. Hazardous in this connotation is about flammability so the soil has to be almost dripping with petroleum for the lab result to indicate it is hazardous. The quantities involved with junk cars make a hazardous result unlikely. So there are hassles and costs associated with disposal.
For dealing with it on site. If the cars were mostly in one area and you can work that area as is, leave it where it is. If not, you may want to excavate the worst of the soil and work that soil in a convenient place. You could try the fungal approach, however, my guess is the concentrations of petroleum compounds wouldn't be high enough to sustain the colonizing fungi alone and you would then have to add additional food for the fungi. This isn't such a bad thing, but a little more work and fuss.
Normally landfarms just spread the soil out and till it frequently. Some of the more volatile contamination evaporates and the soil bacteria deal with the rest. This is high-till gardening - since you want the surge of soil bacteria activity that comes after tilling. Also, the remediation occurs faster in the soil if you do not add organic material. Bacteria will breakdown the easiest to digest organic material available, and most petroleum compounds are harder to breakdown than plant matter. It isn't a big deal if the soil has a lot of organic matter it may just take a little longer to break down all the petroleum hydrocarbons. Also, the bacteria are already in the soil. You could add effective microorganisms if you want. It might help but it is not necessary. The soil bacteria that will break down petroleum are absolutely everywhere.
If you are concerned about it or curious, you can test the soil. There are many different test methods but in this case I would recommend a total petroleum hydrocarbons test like EPA Method 8015. This method can be broken down further into gasoline range, diesel range, and motor oil range. One soil sample tested for all three ranges would probably be about $100-200 (call a lab near you). A test like this adds up the concentrations of a wide range of hydrocarbons and gives you the total. Compound specific tests are more expensive and are a little more complex to interpret. To make a composite sample grab about five hand fulls of soil (of the most contaminated) and mix together then put the sample in a clean, sealed glass jar, bring to lab on ice. The lab may have other instructions for you and have you fill out a chain-of-custody form, etc.
Sure, if you soak the clay with excess water for a day or few it will fully hydrate and be workable. you may want to pour off some of the water before mixing depending on how much excess water you used.
If the clay soil has caliche you may still have hard clumps after the soak, but most soils will break down nicely.