As you said, some water will get there from usual rains but it's nothing to worry much.
It's the 1 or 2 times a year when there are major storms that i'm trying to single out.
Pictures will have to wait as i'm not in that phase yet.
John, true for the maintenance.
I'm just trying to avoid some of it if i can or make it less often.
A possibility would be to make the bottom plaster layer a little thicker.
Either way, as i was told, the secret is in the plaster.
A good lime material is essential - and, at least over here, it means i'll have to slake it myself.
Bagged hydrated lime is garbage.
Kris, Jay C does not visit these forums since about 2 years ago.
Neither does Bill Bradbury nor Terry Ruth, both which had some solid building background, natural or conventional.
Needless to say, there are a some of us with many questions unanswered and some even unasked ...
There will be a pavement outside the house.
One of it,s roles is to divert water away from the foundation.
However, it's a pretty hard surface and under hard windy rain water will hit it and bounce back onto the foundation wall or even on the sill area.
Overhangs i have a little more than 3ft (1m).
Honestly, in this scenario, only 3 times as much overhang will completely protect.
But this is impractical and rain does not always fall perpendicular to the ground.
It's for these rare ocasions that i consider my options.
I'm wondering about the best way to protect the sill area on a SB house.
Since the foundation wall on which the SB rests upon is not very tall (50cm / 20"), there will be some splashing from the area around the building to the wall itself.
The foundation part is well protected but the sill area of the SB wall is making me a little uneasy.
I have locally available heavy duty aluminum window sill that i want to install at the joint between foundation and wood sill plates.
I can then come with the render to meet this area as in the attached drawing.
Now, i have 2 thoughts:
1. Lime render should be done in such a way that it won't crack in this region
2. Careful detailing should be done to stop water ingress
Another thought : if the lime render should stop above the sill mounting heel or come down and rest upon it.
If above, i'll have to put extra flashing behind it to stop water ingress.
If it will come down, it may crack as it's a different material even if i use some reinforcing/ backing mesh.
Regarding the influence of soil type, i'll put some info of my own.
Brett is right when he says that soil type has a large influence on foundation type.
Most problems (but not all) come from water.
If there's a sandy soil that drain fast, you don't need to care much about the water problem as there's not a lot of clay and the excess water will just drain away.
Of course you have to care about the sand being structural but that's a different problem.
But if you have clay or heavy clay, things are different.
Even if you go below frost line, clay will swell a lot if water gets to it.
If you have a gravel trench / stone foundation, water will flow thru to the bottom clay and cause problems.
In this scenario you need the ditch or the entire footprint set at an angle to drain any water to a lower spot.
If you're on a hill, it's simple, but if you're on flat land and if maybe water tables are high ... you have problems.
That's why concrete has a lot of appeal for modern homo impatiens.
People don't have to think and leave out the attention to details.
Basically, concrete is a soil replacement that's not sensitive to seasonal change.
Since it replaces the excavated soil, water can't (usually) get easily underneath to cause havoc.
But if you have a rubble trench, that's exactly what's going to happen.
Loved the wood building replica on the shake table.
I wish more people in the "norming" business would care ...
In this area i think there's just one ant type : ordinary type.
Yesterday i've dug a trench for a foundation, 80cm (32") deep in heavy clay and found many ants hanging out at the bottom ...
I don't know, the last thing i need is for the wife to come and bang a big cooking pan against my head when she gets overrun by ants (she dislikes crawling insects with an ancestral visceral passion) just because i wasn't cautious from the beginning.
1. The house is not built yet, i'm at the foundation stage atm.
I can design the system for 1/200 ratio.
Can you give a link that explains what "zones, exposures, and roofing systems require different ratios" means ?
I figured i would have to have a custom built metal ridge vent since what's available readily doesn't fit the purpose.
2. Got it. If you have any info on how to build a proper ridge vent for a metal roof please put it here.
3. Well, the membrane here has no other purpose except to act as a "backup" roof.
If something happens to the metal roof (punctured, etc), water/snow will get in.
If there's a membrane in place it will stop here and drain outside.
So the whole thing with any membrane in this scenario is that it's a backup roof.
I can think of pros and cons for having one.
As i said in the beginning, i bought a kumquat in a pot from the supermarket.
It most probably came from Italy ...
I placed it in a larger pot where i added some local soil plus some store bought one.
After some time i sensed some wonderful fragrance from this pot and i thought the kumquat had flowered ...
But no, it was this suspect.
Now, i use this same soil mix to repot hundreds of other plants and no perfumed flowers arose till now so i think this "clover" came from the original pot.
That means most probably it came from the mediterranean area which made me suspect trifolium alexandrinum.
I bought some months ago a baby kumquat from the supermarket at a bargain price and repotted it.
besides growing itself quite a lot, something else grew with it.
It looks to be a clover, maybe trifolium alexandrinum but can't be sure.
The flower has a wonderful fragrance which can be sensed from some distance.
I'm really loving this perfume and if i'd knew what species it is i might stretch and look for seed to grow it some more.
I kinda like the looks of having an ornamental brick frame around doors / windows and maybe at corners.
For a brick house it's easy as it's made of bricks.
But for a straw bale one, embedding some bricks could pose lots of problems.
One solution that crossed my mind was to use thin ornamental brick or make thin, 3/8 (2cm) brick slices, and use those as a sort of veneer.
However, since the bales are plastered in lime, i would have to also use lime mortar to fix these thin ornamental bricks.
But lime mortar has a pretty weak bond in this scenario.
Tanks installed outside (buried) will have a temp around 10 celsius. Here main concern is frost and damage due to frost heaving.
Tanks in the greenhouse could get to the 20-25 celsius mark during summer.
It's these that i would like to get a little cooler. Partially burying them (3rd to half height) is something that should mitigate this somewhat.
I will use insulation under my floors, EPS typeII, about 4-6".
Cob would be very easy on the EPS but i'm not sure about RE as the tamping might affect the insulation.
Maybe a layer of cob as base coat and then RE since the cob will spread the load of tamping.
Regarding sand, it's a heat conductor but not a very good one (like stone, concrete, cob, RE, etc).
That's because it has air pockets between the grains.
On the other hand, it's only 3/4" so it's not a lot.
Gypsum has been used in this scenario to embed the PEX but it's a moisture trap, not good for the wood.
The "Heat Rises" metaphor is not quite true.
Heat cannot rise as it's a form of energy.
It tends to travel from warmer to colder bodies by radiation or conduction and between warmer bodies and colder fluids (air for example) by convection.
Hot Air does rise indeed and the phenomenon is called convection.
In your application, there's not much air between the sand grains and the temperature differential is too small for convection to have any significant percentage.
The tanks will be closed but not hermetically sealed.
Material will be ferrocement.
After the first flush, water will be stored in these tanks under darkness.
I don't fear algae but i do legionella.
I am considering putting some outside, fully buried since we have the ground hard frozen for 2 months a year, even if this will complicate matters (digging, insulation, etc).
Brett, if i put tanks buried outside, the hole will have to be deeper than 4ft.
And insulation placed on top due to winter frost.
And i'd have to put a layer of sand between the tank and the hole to accommodate soil movement.
The house build i'm starting work on very soon is set to have earthen floors with hydronic heating.
The exact type is not decided yet : maybe just cob or some rammed earth or Tataki.
Maybe some rooms will have one form and others a different type or maybe there will be bottom cob / RE layer and a harder top Tataki layer.
Anyway, my wife is really considering wooden floors.
And as hardwood is very $$$, softwood (spruce, pine, fir) will have to do.
Where the wife might decide she absolutely wants wooden floors, i reckon putting a floating floor of these T&G softwood boards on top of the leveled earthen floor will also make the hydronic part easier.
These boards are less than 4" (10cm) wide and about 3/4" (19mm) thick.
The only issue that could occur is for the floor to not be thoroughly dry which will warp the boards due to humidity entering the wood.
I have to decide where to place my rainwater tanks: inside the greenhouse or outside.
Either way, they will be at least partially buried since there's not a lot of space available.
And since an off the shelf tank is too much $ for me, i'm thinking of doing them from ferocement.
Now, my preference would be to place them in the greenhouse to be sheltered from the zone 6 frosts and to do double duty as thermal mass.
However, during summer it will be hot in the greenhouse and the water will get warm.
Warmer water is more likely to favor bacteria proliferation.
And since i want to use this water for washing there's an infection risk, think legionella.
Even if burying the tanks 1/3rd in the greenhouse ground, i'm unsure how much thermal buffering the ground is going to offer.
I hope to build about 3 x 650ga (2500 l) tanks.
If putting them outside the greenhouse, insulation will be mandatory plus a higher burial depth.
Well, it's simple really.
Treat the north wall's exterior like your house's wall exterior.
I imagine your house does not have issues with the kind of phenomena you describe.
I mentioned that one change the russians did to the chinese model was replacing the materials.
The chinese people were having little resources available so they used those to the max.
But the russians had industrial materials available (like concrete blocks and foam insulation, etc) and used those instead.
Heck, even for me it's much easier to get hold of industrial materials than natural ones.
So, back to the north wall.
Make it massive and, if possible, insulated on the outside, like a house wall.
If you just want to protect it, siding (wood, sheet metal, roofing metal panels or plain shingles hung, polycarbonate or even PE film) will make sure the wet / frozen gusps won't get to the actuall wall.
The sky is the limit.
Joy Oasis wrote:Can you give us a few points of how is it improved?
The base design is the same with some small changes:
- the size, angles, curvature, etc. is designed to maximize available light for the russian geography;
- the northern part is for storage, shade loving plants, etc. It is not as shady as with the chinese greenhouses;
- there are small ventilation windows on the southern side;
- the northern side has glazing above the wall that contains windows, for ventilation purposes. Together with the southern windows it provides better natural ventilation than usual E-W ventilation;
- the structure is higher. More air means better temperature buffering. More height means larger thermosyphon during hot days leading to natural ventilation.
The other changes are regarding to materials:
- the northern wall is insulated (hollow brick, cement blocks, etc, + EPS or rockwool, depending on cost/avalability);
- the glazing support structure is steel, either plain square / rectangular pipe or trusses, depending on wind / snow load;
- the glazing itself is usually twinwall or multiwall polycarbonate but plain plastic film is also used.
Joy Oasis wrote:I read about geothermal air installations underground, it seems like it is quite expensive and involved project though.
Expensive, well, it depends on how much tubing you need.
For me, it's about half dollar per ft.
For my 600sqft GH i need about 600 ft tubing ~ $300.
Best is to lay the tubing in a trench, about 3ft wide so excavation time + cost is minimal.
But this is all taken into account at design stage.
The russian greenhouses are basically the chinese design made with modern / better materials and an updated geometry to better suit local conditions or needs.
They don't have any geo-air system installed.
The framing will be reinforced with diagonal bracing (4x4's) from top plate to sill plate so there are no problems with racking.
These will be placed in each opening without doors or windows.
Plywood is nonexistent around here anyway ...
The metal connectors are "certified" and the easy route for the structural engineer that makes the plans.
Also, they are very DIY friendly and pretty easy to install but not terribly cheap.
The reinforced connectors offer limited reinforcement, just something to complement the diagonal bracing.
Did you use nails or screws / lag bolts with the angled connectors for your very green lumber ?
I've read some studies that nails driven while wood is green don't hold that well, except helically-threaded ones.
And a screw is very similar to that so it should hold better.
I'm asking because one of the structural engineers said not to use screws with green wood as it will come out by hand after drying.
Of course i went like WHA' ?
I have a little theoretical worry about radial / tangential shrinkage.
Again, not knowing how green the wood will be is a big variable but i think most of it is just surface dry like you said.
Anyway, all the joints in my structure (just a floor level with an uninhabited attic) look something like the attached images.
I don't really care about beams shrinking vertically as all the structure will come down the same amount.
I care about beams and posts shrinking laterally as that will leave all the metal fasteners at a distance.
I thought of putting a vertical peg that will go from the post thru longitudinal beam thru transversal beam thru attic post.
The peg could be galvanized 3/4 pipe and it will reinforce the joint sideways.
For preventing wind uplift, a small vertical strap across all these members should be temporary placed.
After about a year, the metal connectors could be installed at the "final" position, hoping nothing relevant happens after.
But i might be over engineering things a bit ?
Another option is to build the framing as fast as possible and install the bales + plaster.
This way the wood will dry much slower since it will be inside the bales.
Depending on when i get started, the bales won't get installed until at lleast a couple months after the frame is up, possibly even the next year.
So the wood should have some time to dry.
I really have no idea how green the wood will be when bought but i want to be prepared.
I would buy my lumber now and let it dry for a couple months except ... i can't have the property guarded ...
And if i can't have it guarded, that lumber will disappear in no time.
I would use bolts except they would have to be pretty long ... not very practical (long bolts are too expensive) unless i cut them from threaded rod.
And i can use bolts only in a small number of cases.
I'm worried about the shrinking when drying especially for the post / beam connection.
If the post shrinks it's width by 7%, then the metal connectors won't sit tight to it's face but at a distance ...
I can only imagine a situation where the structure is connected minimally until the wood dries enough.
I can put the connectors in place only after this drying.
I'm preparing to start building my strawbale infill single floor house.
It will have a post and beam skeleton, fastened with metal connectors and screws.
The connectors are perforated stell plates and corner connectors like this:
I'm trying to find dry wood which is somewhat difficult to source around here.
Most is green wood and i've been advised not to use it green.
I've been told that screws tightened while the wood is green will come loose once it has dried.
James, Tyler, are you referring to the "ridge vent" band or the membrane to be put between rafters and roof covering ?
If it's the latter, i agree 100% with you.
It only makes sense for modern construction where designers don't quite understand the nature of things and builders almost never.
In my situation, i'm the designer and builder.
After talking some to the architect and structural engineers, i figured they are on a different planet than reality.
They just know one or two things (or they think they know it) and use those as a solution to everything.
They take care of the "looks" and of the structural integrity (as these seem to be the ONLY thing that REALLY matter around here) while i'll make sure that the darn thing actually works, and if i manage to pull it off, i want it to work spectacularly well.
So, to put matters into perspective.
I have a gable roof, 3.2/12 (15 deg) on one side and 3.9/12 (18deg) on the other.
Area is about 1500 sqft (150sqm) on one side and 1200 sqft (110sqm) on the other.
Covering is corrugated metal roof in a light color.
I wanted metal since it works at these low pitches, is lighter, and can come in very light colors to decrease attic heat buildup during summer.
For this much surface area i need a ridge vent with lots of venting area to have proper ventilation.
And at these low pitches, wind driven water and snow can be a problem so it must resist those too.
Most ridge vents spec a minimum pitch of 3/12 or 15deg so i'm covered.
It's the venting area provided and weather resistance i'm concerned about.
Coming back to those membranes, i think the major reason to use them, besides "you have to have one, what do you mean you don't want it ?" mantra, is that you can be less careful to the details (which is how the building industry works unfortunately) and in case something happens to the roof you can just say, heck, the membrane will direct that water to the gutter anyway so i don't care.
BUT, and there's a big BUT.
As you said, what about moisture entrapment ?
I visited a large shop and they had for this purpose some pretty expensive semi-permeable membranes.
My question was, why use them if they're not needed and can cause problems ?
I did not expect an answer.
So, back to the story.
Only reason i would use this membrane is for "backup", in case rain / snow gets thru the ridge vent.
But i get to keep all pieces in case something breaks due to moisture and i don't want that.
I prefer to use a proper solution which is : a good ridge vent.
And this is where i get into trouble big time.
Available are only the 2 types i showed before, both from reputable manufacturers but at different "performance" levels.
These may not be enough and i might need to make a ridge vent myself.
Argh, this is what happens when you care and want to make things right (unlike most contractors, architects, etc.)
Well, ALL roofs traditionally built (meaning older than cca. 20 years) are this way.
It's just that they were done in ceramic roof tile with cemented ridge caps.
Ventilation took place thru the gaps between tiles.
For these roofs, rain penetration potential was higher but they held pretty well.
They have very low water penetration at the ridge though (ridge cap was cemented).
For a metal roof, chances of water getting thru the seams are very slim.
However, water could get thru the ridge vent, since i'm using a cold, vented roof.
The ridge vent band i showed i think has very little chances of water / snow getting in but it also has less ventilation ability.
The ridge vent below is considered HI-END but i'm not sure wind driven water / snow can't get thru.
You'd have to trust the brand and marketing mumbo jumbo.
I don't have access to track record data of this band in similar climates.
I have a cold, vented attic in my SB plans.
The one where wind "howls" thru it.
The insulation is on the floor and there's no traffic as it's uninhabited.
Just a small hatch from the outside for inspection / servicing.
The actual roof is rafters with battens over them and metal roof above (no sheathing).
Something roughly like this:
There are soffit vents plus ridge vent for the entire length of the gable roof.
The ridge vent is some form of membrane that's permeable to air but not to water / snow.
Now, it seems over here people can't / don't know how to build anything unless it's engulfed in plastic sheets / membranes.
It was recommended to me that i place a membrane of sorts above the rafters and below the roof supporting battens /counterbattens.
I asked why since i was curious (not really) on the arguments.
I can find some pro's and cons.
Good air circulation all over the attic
If something happens to the ridge vent or the metal roof, water can drop to the insulation below - bad
If the above negative happens, you'll know very soon due to the ceiling wet spot (unless you have a waterproof layer there)
Inspecting everything is easy as everything is in sight
In case something happens to the roof or ridge vent, water will flow above the membrane to the gutter
You can't inspect what's going on above the membrane as it's not transparent
Less air circulation in the attic, most between roof and membrane
Gutters are present.
But they can only divert water that lands on the roof.
Imagine rain falls straight from the sky, 90 degree to the soil surface.
Some falls on the roof and is diverted by the gutters towards your discharge of choice.
The perimeter of the house is protected by wide (3ft) overhangs.
Now imagine there's wind blowing the rain at 45 degrees to the soil surface.
What falls on the roof is diverted by the gutters, just as before.
But now, some considerable amount of rain will splash on the house walls and perimeter foundation (grade beam / elevation).
You'd need 10ft overhangs for this not to happen.
It is this water that i'm trying to shed away from my walls and foundation.
Travis, makes sense as that's something i wanted to do.
But intersecting local regulations (fence clearances and other aesthetic junk) with the usual sizes of postage stamp properties sold today - you have almost zero crossing.
It was hard enough to design the house to be livable, according to my wife's and my own standards, considering the current limitations.
Just for an example, if you have a post (wooden or otherwise), then that's considered house perimeter (limits) and obeys all the nasty stuff mentioned above.
Does not matter if it's a porch or a wall.
We've done a porch this way on one side of the house, 10ft deep so i'm well covered.
It took a lot of space as we had to move the whole house to the back by this same distance (front fence to first post / house wall distance has to be an exact number), and will cost a lot in taxes (it's considered inside the house) but there was no other way.
On the opposite side of the house there will be a lean-to greenhouse so that's covered also.
The other 2 sides don't have any posts or anything attached.
Without posts or heavier supporting structure, eaves overhang is 3ft.
It protects pretty good the side / foundation from usual, slow rain.
But we get also heavy, windy, diagonal rain and there's a lot of water in these.
3ft overhangs are not enough protection.
Only thing i can do is to do this 3ft wide "sidewalk" thing that on at least one side of the house might widen to double that turning into an open-ish "porch".
If a cover is needed, it will most likely be some vines, like grapevines and that's only good for summer shade.
It won't stop rains from getting thru.
Basements can work but only if done right, as you showed.
My area is a former swamp, very clayey-silty soils with shallow groundwater present in many locations.
Some sites have water at 2ft depth but at my house location, water level is way lower, about 13ft down.
I don't have a basement as i don't need it.
The floor is elevated atop the ground beam by almost 2ft.
Even so, i prefer to let / help water get away from the foundation / ground beam.
Less water, less movement in the clay and less thaw / freeze issues.
Around the house perimeter i intend to build a sidewalk sloped such as to let water flow away.
This sidewalk will end in a gravel ditch, with or without drain tile, i haven't decided yet.
This ditch will then slope to a dry well far away from the house, most probably a mulch basin of sorts.
My only remaining issue is how to do this sidewalk.
I'm pondering laying flagstone in a gravel bed since it's cheap, weather resistant and good looking.
Some water will flow over the flagstones but some will inevitably pass thru the joints.
Therefore a water barrier under the gravel is necessary, so that all water ends in the drainage ditch.
This barrier could be plastic sheet, bitumen membrane, a layer of heavily tamped clay, or something i haven't thought about.
I am biased towards natural solutions but in the end, the solution that works will be chosen.
It is this part i need advice for.
I don't have a basement, i was just too lazy to make my own drawings and took some from the internet that happened to show a basement.
My foundations are just some 12" diameter piers going to the frostline, on top of which there's a grade beam.
I need to take care on what's outside the grade beam, shedding rain water away so it does not get underneath and inside.
Water going into foundations can cause big problems if you have expansive soils or freeze/ thaw cycles.
In my neck of the woods, the panacea for this is to pour a concrete pavement (sidewalk) around the foundation about 3ft/1m wide and 4in/10cm thick.
This sits on top of a gravel layer with the same size.
The concrete is above grade, sloped about 3% away from the foundation.
The joint between foundation wall and pavement is filled with bitumen to ensure an elastic seal.
sheds water away
It's concrete ... not natural
it's clean, stable and can be walked upon
If there's a need to do something underneath it, good luck
material is readily available and somewhat cheap
Can disintegrate in a few years if not done right
any random person can do it
It's a hard surface and rain falling on it will splash hard the foundation wall leading to more erosion
Below are some proposed solutions as found on the web.
Waterproofing using plastic membrane
Waterproofing using compacted clay layer
I am curious as what other solutions exist worldwide, especially for old / vernacular buildings.
I need solutions that work, preferably using more natural materials (if available and at a decent cost), but will accept "conventional stuff" if it makes sense.
One other thing i,ve seen used, mostly in the US, is gauging lime plaster with gauging plaster (gypsum).
The reasons for doing this are many.
- it has much shorter setting time because of the gypsum;
- it can stick to drywall, again, because of the gypsum;
- it's less vapor permeable than pure lime plaster which can be a plus for a ceiling;
- can be much stronger than any of them taken separately.
The gypsum to lime ratio could be anything from a scoop of gypsum to a lime plaster bucket up to 50 / 50.
Disadvantages, well, if gypsum stays wet long enough, it will disintegrate.
I really appreciate your experience.
You said gypsum scratch and brown coats.
What kind of gypsum ?
I have access to bagged gypsum (not agricutural).
It comes in roughly 2 flavours: builder and tinkerer / modeler
Builder's gypsum i assume is raw material, without additives, setting time between 7-15min.
The others have setting time of 30' to 1hr.
I prefer the raw gypsum, even if it's harder to work with (fast setting time) as i'm more certain there are no nasty additives.
Regarding lime, what kind ?
Bagged, hydrated ?
If so, it's available everywhere in 80% purity.
I would prefer 90% purity but that's harder to come by.
Regarding the 3 layers, why do you have this specific preference?
I'm genuinely curious.
The scratch and brown is just pure gypsum or mixed with sand ?
And why not a gypsum / lime mix (maybe 50/50) ?
And the finish, just lime / gypsum without sand ?
Also, on every bagged gypsum product (builder's or gauging plaster) it's specified to not use on wooden substrate.
Do you know why it's so ?
Is there some chemical / mechanical (moisture absorbtion) going on ?
Or it's just that gypsum can't grip a solid wooden sheet (like plywood or OSB) ?
Thanks a lot for taking your time to answer.
This is really important for me.
The walls have to be more permeable than the ceiling.
For the strawbale walls i will definitely use lime plaster because of the vapor permeance and since it's anti-fungal.
The ceiling needs to be much less permeable since warm air that contains humidity will rise to the top.
If it manages to get thru the plaster and into the rockwool insulation, it will condense and cause trouble.
That condensate will reduce insulation performance and at some point it will drip down to the plaster.
And that's not good.
In your experience, what's the behavior of this system if something happens to the roof and water drips on the insulation and finds it's way to the plaster ?
As anecdote, i remember some years ago i visited a local village and had a talk to the resident priest.
He told me that when they built the church in 1910 or something like that, they had wooden formwork supported by some steel framing for the cupola.
They poured lime (i guess it was actually lime mortar) in that formwork.
The interesting thing is that they used some gypsum in the mixture, as a fast setting agent, so they could remove the formwork in about a week and, because gypsum's fast set, it had enough structural strength for the whole thing to self support.
If it would have been lime alone, that formwork would have been there for months at a minimum.
It seems "hot lime" and hydrated are completely different beasts regarding plaster behavior.
For a lath and plaster (wood lath and lime plaster) ceiling, what should be used ?
Hot slaked aged for some months or hydrated lime aged for weeks ?
I'm asking because hot lime is not easy to obtain and slaking large quantities can be a problem.
On the other hand, hydrated lime in bags is only 80% purity ...
In any case, i know how much plaster volume i need.
But how much powder lime ?
If hydrated, i calculate 1/3 hydrated powder lime / sand and age that powder underwater for weeks.
If i use lime paste, the ratio should be about 1/2.5.
But if i can use hot lime, how much do i need to slake ?
I could not find any relevant info on this.
Regarding gypsum, i want to know more about how it can improve lime plaster and maybe how can it be used by itself.
Application is for a one level home that has a cold roof.
The insulation will be on the attic floor (mineral / rock wool).
The ceiling of the rooms should be pretty airtight and not very permeable so vapor can't go in large quantities and condense inside the insulation.
The walls will be lime plaster (over strawbale) and that has to have a good connection with the ceiling to avoid air leaks.
Lime plaster is preferable since it can handle humidity variations well and also some water if the roof somehow fails and it has a leak.
Alternative would be drywall but it's going to be terrible to keep air tight and will fall apart in case of water.
I got interested after i found out about permaculture.
I'm an energy/electrical/electronic guy and, honestly, i don't see this as going anywhere, period.
It's just serving it's own purpose.
But living systems, now we're talking about.
One of the primary purposes of life is to grow and enhance life.
The entire face of the earth is continuously changed by life.
So i said to myself, this should be it.
On the other hand, plants are easier to deal with than animals, and a certain so called "wise" one.
So, i studied and i went to holidays in Greece.
I always prefer this country for my holidays for too many reasons.
And, while the wife and kids were happily sleeping the afternoon, i got going with some digging / cutting / collecting tools in my pouch.
So i took plenty of cuttings and fists of seed plus pictures.
I used the pictures to search the internet for the name of the plants so that's how i know what they are.
Of course, the purpose was to figure out what i could grow back home, which is surprisingly A LOT.
So, when i go to Greece, i see and feel a lot of history (ancient and modern), and IMMENSE potential, untapped ...
Everything could be green and happy.
Of course, speaking to the natives, they don't see it that way.
They're very surprised to find out what that lunatic is doing in that "abandoned field of weeds".
Imagine they're surprise when i tell them i collect "medicinal" plants.
Yeah, that blue eryngium is cure for that cold you have last winter but you just burned it ...
I wish i could have a plot of land in your country ... the things i could do ...
Ok, time to stop dreaming.
Just so you know, even if i live in a different climate, things are not very different both as difficulty and amount of damage we as humans have done and continue doing to the planet.
I do envy you for the mediterranean climate with its warm winters and scorching summers.
People find the summers hard because of the heat but shade is a very good solution.
Rain lacking during summer is a big issue but it can be mitigated, in time.
I prefer that to having the ground frozen solid for 2 months ... and 6-8 months of the year being cold.
The weeds i mentioned, i got some fists of seed from them.
It was easier to get them from greece than spending extra time and collect them locally (municipalities like to cut anything that grows much earlier than seed setting time).
All of them i planted in my property.
And my property is worse than what you have.
Not even the weeds grew ... except Silybum marianum which survived even the sheep.
If you can get hold of the seed, it's gold.
I don't have the scorching summer but topsoil is just 10cm with some small grasses then 10cm of hardpan.
A shovel is a no-no, a pick-axe will show some success (deep sweating).
During rains it saturates and flows downhill.
As soon as it dries, it gets tough as concrete.
And i can't grow hardy stuff that you can because of the frigid winter ...
And, the local shepherds don't give a dime about private property and come and go with the sheep many times a day.
This is going for more than 30 years ... hard habit to heal.
What did grow, and maybe you could get hold of some seed, is buckwheat.
It grows like crazy in almost zero fertility.
I think for you it should work as an autumn crop, planted maybe in early october.
It is a cooler climate crop but you have cool winters.
I bought 2 x 25kg sacks from a pidgeon supply store.
I thought i try and they grew like mad.
They did not set seed since i planted them late May, just in time for hot weather.
Whatever survived was mowed by the sheep.
So, natural shops could be a source of seed, tea bags like Fenugreek, seeds of Flax, Amaranth, etc.
Spice shops can also have a lot of seed material (Carum carvi, Cuminum cyminum, Melilotus officinalis or album, Pimpinella anisum, Cardamom, Thymus, Coriander, Foeniculum vulgare, Poppies, Nigella, Oregano, Mustard, Pepper, Sesame, etc).
Animal food shops (especially birds) can have tons of good stuff. I have grown some Nyger (Guizotia abyssinica) that looked very nice. 1kg bag about 2.5 Euro, plenty of seed.
You could also try Phacelia for the insects, especially bees.
And a local hardy aromated shrub - the Laurel (daphni).
I have tens of gigabytes of pictures, documents and other stuff but i have to remember to take a look again.
I might find something of potential.
Anyway, enough with the babbling.
You should have a good "shopping" list, you only need time, and that is always problematic.
PS. One other tree good for humans and wildlife, Myrobalan - Prunus cerasifera (Prunus divaricata) - grows itself.
My wife's grandmother spit a kernel seed one day, next year the tree was 2m tall and the next year full of large red fruit.
Beat that if you can. I've also seen them grow happily in greece so, godspeed.
If it's wooden lath you're talking abut, don't worry for the smoothness as it's not extremely important.
Just "paint" it with plain water and let it dry.
Do this 1-2times and it will form some scales which will make it very rough on the touch.
Lime plaster will love it.
You'll have to wet it before applying plaster anyway, so it does not suck all the moisture and make a weak plaster.
Yaeh, there is also metal lath.
Here's a nice description.
It's basically perforated sheet metal or expanded mesh.
The expanded mesh is better because it has depth but also requires some spacers when fixing to the joists.
Alternatively, it could be placed directly but the key at the joists will be less - which could lead to some cracks as the plaster thickness will be lass than between joists.
If it's mild steel it has to be galvanized / Zn coated otherwise lime will rust / eat it in no time and taint the plaster in yellow.
Alternative is stainless mesh but that will put a big hole in your pocket.
For me, even galvanized expanded mesh could be too expensive.
Wood lath can be strenghthened by using fiberglass mesh.
On top and below the lath.
It seems in my area the expanded galvanized lath comes in 2 galvanizing flavors.
Chemically galvanized 1.5 year lifetime, decently priced.
Thermal Zn coating, 12 year lifetime, price is much higher ...
I did some calculations.
For me, wood lath (raw wood + cutting) + fiberglass mesh + nails is about 3 times cheaper than the cheapest expanded metal lath.
Labor is higher though.