Living in Paper-construction

7/24/2019 Living in Paper-construction

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Home Mixes Mixers Forms Construction Domes & Vaults Tests Starting A Business

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The Site Waterproofing

Building Codes Pouring The Roof

The Foundation Windows, Doors & Cabinets

Building The Walls Plumbing & Electrical

Installing The Roof Finish - Exterior & InteriorFloors

Making Roof Panels Heating & Cooling

Hands On Current Projects About Us Contact Us Acknowledgements Get Yours

THE SITE

The first thing you have to look at in any kind of construction is the site. Orienting the home to takemaximum advantage of passive solar design is of prime importance. It may also be possible to usethe contours of the site to help design the home. For example, if there is a high spot on the site, it

may be possible to build part of the structure into it to take advantage of earth sheltering, or toconstruct a lower level or basement. There may be other things on the site, which can help you -and some you may want to avoid. For example, the earth and rocks on the site may be material youcan use for building, but there may be low areas on the site, which should be avoided due toflooding. Some of these decisions are value judgments, which require time and contemplation toevaluate. If a spot feels good and meets practical requirements, it's more than likely the best place.Many additional ideas on "Siting A Natural Building" can be found in a book titled "The Art OfNatural Building".

BUILDING CODES

Building Codes are intended to protect the health and safety of people occupying a structure orthose possibly affected by it or living near it. There is nothing wrong with Building Codes per se, butthey are sometimes used to unnecessarily prohibit perfectly safe procedures or to limit alternatives.In some cases this is intentional, for example to limit construction procedures and materials tothose championed by special interest groups. But sometimes there is just not enough goodinformation available to allow Building Safety personnel to deviate f rom the book. This is wherediplomacy and knowledge come in handy. Usually showing respect, knowing precisely what youwant to do, and having good plans to accomplish it go a long way toward establishing rapport withBuilding Safety personnel. Usually your plans or procedure gain a lot of credibility if you can find astructural engineer or architect who is willing to approve (stamp) them. This approval stamp oftencosts quite a bit of money, but some practitioners have found progressive architects who areinterested in working with innovative materials and charge very little.

Building Safety personnel have reason to be cautious. They don't want to be held responsible for

approving a product or procedure which turns out to be unreliable or even dangerous. In manycases, it is possible to work with them. I have had very good experiences with those who have t imeand are willing to listen. I'm not sure that any of the following construction methods are approved inthe Universal Building Code, but they have been used in structures which have been standing foryears.

THE FOUNDATION

The function of a foundation is to support the load of the walls and roof of a structure, preventsettling, and provide a solid anchor point to hold the structure together. The foundation has toextend to a depth just below the frost line in your area. Basing the foundation below the f rost line


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Tires are stacked offset like bricks.Drawing courtesy of Building WithEarth by Paulina Wojciechowska.

Rubble footing with sand bag stem.Drawing courtesy of Building WithEarth by Paulina Wojciechowska.

concentrates the load of your structure where it is much less subject to heaving. Heaving ismovement caused by the expansion and contraction of moisture changed to ice during the freeze -thaw cycle. The foundation is usually comprised of a footing and stem wall. The stem wall is placedon the footing or is poured as part of the footing. The function of the stem wall is to elevate wallconstruction materials - in this case papercrete - above the ground. This serves to isolate them frommoisture and provide a barrier against bugs and pests.

There are a number of ways to build footings and stem walls. One of the most common ways is topour a concrete footing and stem wall in a single monolithic unit. This involves excavating a footing,placing steel rebar horizontally and vertically, and building forms to support the stem wall. Thereare variations on this approach, but they all cost quite a bit of money, and use a significant amountof concrete - in fact, the footing and stem can cost more than the rest of the papercrete structurecombined. Concrete is strong and quite reliable, but has the propensity to "wick" moisture. I f t hereis water in the surrounding soil, concrete will absorb the water through capillary action and pool iton its surfaces, including where the papercrete walls meet the stem wall. Since papercrete is veryhydrophilic- absorbs water quite readily - this situation has to be stringently avoided. Ideally, theconcrete footing and stem wall are isolated from the surrounding soil with drainpipes and/or a layerof gravel to drain water away. Additionally, some kind of barrier has to be placed between theconcrete and the papercrete - either a good liquid sealer or a physical barrier like a polyethylene sillsealer.

There are other ways to build footings and stem walls withtires or with rubble and sand bags. These methods are notformally recognized, but people are using them. Thefoundation with tires involves digging a t ire-width trench,

filling tires with gravel or earth, laying them horizontally inthe t rench, filling the tire openings with gravel or earth,tamping them and then constructing a stem wall on top ofthem.

This general approach is used in earth ship (rubber tire)construction for the foundation as well as the walls. Diggingwide trenches and f illing tires with earth is very laborintensive, but it works quite well.

The easiest and least expensive way that I've heard of is tobuild a solid foundation for papercrete walls is with rubbleand sand bags. It is not code, but variations of it have beenused successfully to support many structures. A trench

several inches wider than the wall is dug to just below thefrost line. Thoroughly tamp the bottom of the trench.Starting at the bottom, layers of progressively smaller stonesare placed on top of one another. The bottom layer shouldbe the coarsest, perhaps 4 inch (10 centimeter) stone,followed by a layer of 2 inch (5 centimeter) stone, followedby one-inch (25mm) stone and ending with pea gravelseveral inches above grade. Screening your own gravel is alot of work, and it is not often possible to get uniformselected sizes commercially. Usually the sand and gravelyards sell ranges of sizes like 1/2" - 3/4", 3/4" - 1 1/2", 1 1/2"- 3", 3" - 8", 6"+, etc. (1.3 - 1.4, 1.4- 4.0, 4.0 - 8.0, 8.0 - 20.0,15.0+ centimeters)

If you can pick up what you need yourself, the prices average about $6.00 a ton. I f delivered, figure$15.00 a ton plus a truck rental charge. The thickness of each layer and number of layers dependson the depth of the t rench. As each layer is added, it is tamped and leveled with a tamper or a 2 x 4until the last layer is a few inches above grade. Then two layers of sand bags are laid on top of therubble foundation. The sand bags become the stem wall. Make sure that sand or small gaugegravel is used to f ill the bags. If earth is used, and there is a significant amount of silt or clay in it,there is a good chance the bags will wick water more readily than concrete. Also be sure that thesame amount of sand is placed in all bags. If the amount of sand varies significantly, the size andthickness of the bag will vary making it diff icult to keep the stem wall level and uniform in thickness.

This is a problem especially when more than one person isfilling bags. I found a way to keep the amount of sandconstant and hold the bag open as well. I bought an 8-inch


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An 8-inch piece of stovepipe holds t hebag open and measures the amount of

sand.

A post driver is used to start the rebar.A mall is used aft er the rebar is far

enough in to be stable.

Some of t he walls at Chaco Canyon arethree stories high, built on the ground,have litt le or no mortar and have been

standing for hundreds of years.

(20 centimeter) diameter piece of stovepipe and placed it inthe bag. When filled, this stovepipe piece held a litt le toomuch sand so I cut off a section until it held just enoughsand for the type of bag I was using. Incidentally, there is atendency to overfill bags. If overfilled, the bag will belly outand become overly round - even after tamping. This makeslayers of bags unstable. I t's best to look at the creases ofthe bag and tamp a few bags to determine how thick thebag should be f illed. The idea is to get the most f lat solidarea after tamping. After f inding out how much sand it takesto do that, pour the sand from that bag into the stovepipe,

mark it and cut if off so that only that amount can be added. The stovepipes are cheap - five or sixdollars. I t's easy and inexpensive to make these "measuring cups" so that everyone filling bags hasone.

Layers of bags are laid with off set joints like brick. Two strands of barbed wire are placed in parallelalong the length of - and between the layers of - the sand bags to keep them from sliding acrossone another. To keep the papercrete wall from shifting on the sand bags, 3/8 inch (1.8centimeters) rebar is pounded through the sand bags, at two to four feet intervals, as deep into therubble footing as they will go. Pounding rebar through the rubble footing may be diff icult, but I 'mtold that the rebar sometimes finds its way between the stones. Most people start rebar with a postdriver.

They cost about $20.00 at Home Depot. It s a lot easier on

the hands than using a mall. The post driver leaves a fewinches protruding, so a hand mall has to be used to poundthe remaining length of the rebar all t he way in. But at thatpoint, the rebar is stable enough to save hitt ing yourknuckles with the mall. I f the rebar will not penetrate thefooting at a given point, try pounding it in at a differentangle. I f the rebar won't go into the foundation at all, justleave it impaled in the bags. The idea is to stabilize the firstfew courses of papercrete on the sand bags, not nail thebags to the footing. The weight of the bags and thepapercrete will keep the walls from moving on the footing.

Actually, at least one home I visited had no footing at all.The site where the home was to be built was very sandy and had no problem with drainage. The

seasonal temperature changes were not extreme enough to cause heaving in loose, sandy soil. Sothe builder simply leveled an area for the home, and then spread out about six inches of scoria, aporous volcanic rock, for sub-floor drainage and insulation. Next he laid a few courses of sand bagsright on top of the scoria. He f inished the entire building, walls and roof, with bags of scoriacovered with papercrete. So, absent problems with drainage and frost heave, if walls are thick (i.e.building loads are spread over a wide base), footings may not be necessary. Many ancientbuildings, standing for hundreds of years, are built on the ground without footings.

In fact, un-reinforced rubble and shaped stone have beenused for foundations and walls for centuries before Portlandcement and rebar were discovered. Some of the earlyNative American stone structures of the Southwest, likethose at Chaco Canyon and Pueblo Bonito, are centuries

old, several stories tall and still intact. Some have mudmortar and others have no mortar at all. Larger stones werechinked so skillfully with smaller stones that nothing elsewas needed.

Tamping together layers of progressively smaller stonespromotes drainage and strength. Wedging smaller stonesbetween larger stones would seem to stabilize the layersand distribute the load in a horizontal as well as vertical

plane. Unlike a concrete footing and stem wall, a rubble footing with sand bag stem wall willtheoretically not wick water at all.


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A post and beam home with papercretewalls used as in-f ill.

Rebar protruding above a concretefooting.

Building With Earth ,by Paulina Wojciechowska, has a detailed section on foundations. We planfurther experimentation with these foundations early next year.

BUILDING THE WALLS

Ironically, the first decision about walls starts with the roof. Will the papercrete walls support t heroof or will the roof be supported some other way? Currently, it is diff icult to get a permit to build ahome with papercrete if it is load bearing," that is if the roof is supported by the walls. Not enoughtesting has been done. It is easier to get approval to build roof-supporting garages, sheds or otherstructures, since they are not intended to house people. Many localities will permit papercrete wallsas in-fill for homes - that is as non-load bearing walls built between roof-supporting posts. Theposts are connected to the foundation at the bottom and tied in to beams on top. The roof systemis built on top of the beams. This approach is commonly called post and beam."The posts and beams may be made of wood or steel or acombination of both depending on local building codes. Iknow of one home built with steel post and beam materials,which the owner was able to obtain nearly for free, becausehe was an expert welder. If you want to build inexpensively,you will become familiar with your local demolition and junkyards. Its often possible to obtain excellent deals onbuilding materials in these places, while at the same time berecycling valuable resources. If the building authorities in

your area go entirely by the book, be careful to check withthem regarding what recycled materials are permissible.

No matter which method you choose to support your roof,the walls are built t he same way. The rebar, as described above, has ideally been pounded into therubble foundation, and has been allowed to protrude a few feet above the sand bags.

The first three or four courses of papercrete will have to bedrilled or impaled on the protruding rebar, or poured in placearound the rebar. The rebar is meant to prevent horizontalmovement. Pounding it into the rubble foundation won'tprevent the walls from lifting vertically, but if somethingcataclysmic happens to lift the weight of 12-14 inch (18-35

centimeter) thick papercrete walls, chances are that nothingwould have kept the structure f rom lifting.

When just a few inches of rebar are visible above thecourses of papercrete, it's time to lay a piece of rebarhorizontally and wire it to the protruding vertical pieces. Thenpound the vertical pieces down almost level with the surfaceof the papercrete, cover it with a layer of papercrete mortar

and start laying the next courses of blocks. I t's a good idea to keep the thickness of the mortarjoints to a minimum whenever possible - ideally about 1/2" (1.25 centimeters). Otherwise, the thickmortar joints will shrink and your finished walls will lose a bit of height when the mortar is fullycured. This is a good reason to wait a few weeks af ter the walls are up (longer in damp climates)before installing windows and doors. If the mortar joints are thick enough to allow excessive

settling, windows may be broken and doors may not open very well. Usually, excessively thickmortar joints occur because not enough attention was paid to keeping the blocks level, square andtrue as the walls were built - t he lazy way to make height and alignment adjustments. Some of thisis unavoidable and not very important, but building the entire height of a wall with 2"-3" (5-7centimeter) mortar joints will result in some settling. Using a mortar mix rich in Portland cement willminimize shrinkage and encase each block in a fireproof "container."

But let's get back to installing the rebar. After laying upanother two feet (61 centimeters) of blocks, pound morefour-foot (122 centimeters) rebar through the block layers ontop into the block layers below. Repeat the process above,laying a piece of rebar horizontally and wiring it to the


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Horizontal rebar is t ied to vertical rebarfor additional strength.

Openings can be f ramed out f or doorsand windows as walls are built or t heycan be cut out with a chainsaw later.

A post driver is used to start the rebar,a mall is used to drive it in t he last few

inches.

protruding vertical pieces. If you're using slip forms insteadof blocks, you can wire the horizontal and vertical pieces ofrebar together, starting at the stem wall, and pourpapercrete around and through them all the way to the topof the wall. This pins the entire wall together and provides agreat deal of lateral strength.

There are two ways to plan for openings in the wall - either frame as you go or leave the rebar outand cut openings to size with a chain saw at a later time. I f you have all of your windows anddoors, or know the size of the openings, you can build frames for them as you put up the wall.

If your walls are load bearing, the f rames should besubstantial in case the finished walls settle slightly at themortar joints. Do not install flimsy pre-hung doors orunframed glass as you go in load bearing walls. The settlingthat occurs is usually slight, but could be enough to breakunframed glass or knock door jams out of alignment. If youdon't know exactly what your opening sizes will be, leave therebar out of the places where openings in the wall areplanned. You can cut them to size later with a chainsaw.There is one caveat here. If you are using sand or othersolids in your mix, or if you are using more cement to paperthan a 50-50 ratio by weight, you may have great difficultytrying to cut openings in the walls after they are dried.

Conventional chain saw blades do not cut through sand orhardened cement very well at all.

INSTALLING THE ROOF

When you have reached roof height, you have a decision to make. You can attach a wooden plateto the top of the wall and build a conventional roof f ramework from there, or you can use vigas.Vigas are smaller-diameter logs used as roof beams. Some builders drill a hole in the vigas andanchor them to the wall by pounding a long piece of rebar into the papercrete and bending it overthe viga. If you want to distribute the weight carried by the viga over a greater area, you can notchit with a chainsaw and position the f lat area on the wooden plate attached to the top of the wall.

The wooden plate can be attached to the wall in severalways - either by 3/8 or! rebar, or by spot welding shortpieces of threaded rods on one end of short pieces of rebar.If the rebar is used by itself, without the threaded rod, drill ahole in the plate and pound rebar into the papercrete as faras possible, hopefully a minimum of two feet. It's mucheasier to use a post driver than a mall or sledgehammer todo this. Allow 4"- 6" (10-15 centimeters) of the rebar toprotrude from the hole and bend it over f lat with a hand mall.This should be done every three-four feet depending onwhat is beneath the spot where the rebar is being placed.Sometimes obstructions below where the rebar is beingdriven, like window openings, can be avoided by driving the

rebar in at an angle. Bending with a hand mall tends toenlarge the hole made by the rebar and move the block out of position, so the preferred method isusing the threaded rod.

Weld a four inch piece of threaded rod on one end of as many pieces of rebar as you need to holdthe roof down. In essence, you make very long bolts. Drill a hole in the wooden plate, and drive therebar into the papercrete until an inch or so of the threaded rod protrudes above the wooden plate.Place a flat washer over the threaded rod and t ighten down a nut. Do this every 3' - 4' feet alongthe wall. The wooden plate chosen to distribute the roof weight on the wall should be narrower thanthe wall - perhaps a 2x10 - so that papercrete can cover it outside and inside.

In my experience, adding a litt le Plaster of Paris topapercrete mix causes papercrete to adhere solidly to wood.


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The wooden plate for the roof isfastened to the wall with threaded rodwelded to rebar. The rebar protruding

vertically is driven through holes in theplate next t o t he holes with t hethreaded rebar. The vertical rebar willhold block in place, which is laid above

the roof line.

Off set chicken wire and thin layers ofpapercrete are installed before the roof

panel.

Apply a second thin coat of papercreteto stick the roof panels in place and

The rebar method of attaching the roof f ramework to the wallhas been used in structures in Colorado and New Mexico,which have successfully withstood weathering and stormsfor a number of years.

After the roof framework has been installed, you have todecide whether you want to build a conventional roof, apapercrete roof or a hybrid papercrete-conventional roof. Aconventional roof is quite expensive; it averages about fortypercent of the cost of the entire structure. A conventionalroof has to be well insulated, or the insulating value ofbuilding the walls with papercrete will be wasted.Conventional roof systems are much more expensive thanpapercrete. According to one practitioner, a six-inch thickpapercrete roof can be constructed for about 75 cents persquare foot, including a paint sealer. A Spanish tile roofwould cost $11.00 per square foot.

MAKING ROOF PANELS

If you choose a papercrete roof, you have to decide whether you want to make papercrete roofpanels or pour the roof. Pouring the roof is not practical if there is no water on the building site andit can't be t rucked in. In that case, roof panels can be made elsewhere and brought in with a pickupor utility t railer. When making roof panels, it's best to carefully level the ground where the panels willbe made so the thickness of the panels is consistent. Papercrete panels are made with 2' x 4' (61 x122 centimeter) forms. The 2' x 4' forms should be built of 2 inch by 4inch (5 x 10 centimeter)lumber. I f you make larger, thicker panels, they will take longer to dry and you may need help to getthem up on the roof. To keep the papercrete clean and help drain out the water, put a sheet ofshade cloth on the ground under the form. Some people use more cement in the mix for roofpanels. Adding too much cement will negatively affect R-value. Strong panels are made by pouringabout two inches of papercrete mix into the form and then spreading a piece of chicken wire overthe mix. Pour the remaining two inches of mix, smooth out the surface with a trowel, and let it set.In the desert Southwest, you can pull off the form for the next panel in about half an hour. Youshould be able to handle the panel in about four days. It will probably take a week or so tocompletely dry.

For the greatest strength, roof panels are installed overoffset chicken wire and two thin layers of papercrete. First asheet of one-inch chicken wire is tightly stretched over theceiling joists or vigas of the structure and fastened in placewith heavy-duty metal staples. A second layer of one-inchchicken wire is of fset 1/2 inch f rom the first and installed thesame way. Then a thin layer of papercrete is spread on thechicken wire and allowed to dry to form a strong base for theroof panel.

Just before installing the roof panels, another thin layer ofpapercrete is spread over the base layer to mortar thepanels in place. Then they are screwed to the roof joists or

vigas. Since papercrete is relatively soft, the screws don'thave to be as long as the papercrete is thick. They easilycountersink into the papercrete as they bore into theunderlying joist or viga. Once the first layer of panels are inplace, you can mortar and screw on additional layers ofpanels or pour a layer of papercrete. If the roof is relativelyflat, pouring is no problem. If greater than a 4/12 pitch, itwould probably be better to mortar on a second layer ofpanels.


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then screw them to the ceiling joists orvigas.

This five year old home is covered withpapercrete without waterproofing. It

hasnt leaked.

A papercrete roof with surface cracksand separations, but no leaks.

A pond made of papercrete sealed withcrystalline waterproofing.

After the second layer of panels are added, a thin layer ofpapercrete should be added over the outside surface to fill the cracks and smooth out the entireroof surface. At this point, you can choose to leave the papercrete untreated, waterproof it, oradopt a hybrid approach - cover it with insulating foam or steel sheeting.

Kelly Hart has lived in a sand bag home covered withuntreated papercrete for several years with no leaks. Hishome is located in an area where there is snow, andaccompanying freeze-thaw cycles. The roof structure on hishome has a fairly steep pitch, like a cone, but he says

rainwater does not drain off; it sinks in before it can reachthe ground - and then evaporates.

I have also visited a location in New Mexico and walked onthe nearly flat untreated papercrete roof of a shed severalyears old. The papercrete had cracked and separated on thesurface a bit, but there was no evidence of leakage.

Some people write that it is possible to waterproofpapercrete with elastomeric paint like Kool Seal or Henry'sproducts. Elastomerics are quite expensive. I've examinedthese products and they produce a thin, flexible rubber-likemembrane when dry. When I peeled a small sheet of it off acontainer and tugged on the edges, it didn't stretch very

much before holes started to form in it. I think it would sealthe roof if it stayed absolutely intact, but no one knows forsure how long this membrane will remain flexible andundamaged under the ultra violet beating of the sun - or incyclic f reeze-thaw situations. Even roofing tar hardens andultimately cracks in the sun. A papercrete roof is slightlyspringy; it has a little "give" in it . I would worry about walkingon it and stretching the elastomeric membrane. If it cracked

or perforated at all, and water were trapped under it, mold, mildew, fungus or degradation in thepapercrete could follow. One practitioner is extremely concerned about mold. He feels that using asolid papercrete roof is risky "except when another kind of material (such as a metal roof) isassembled over it, and the papercrete can breath to allow any possible leaks to air out. Thisappoach is also much more healthy for the inhabitants of the structure, since breathability has been

established as desirable for a "healthy" house."Two other practitioners I spoke with said that elastomeric paint has a good record when used perinstructions. Applying elastomeric paint is a two-step process. If the primer and f inishing coat areused as recommended, it gets high marks they felt. Both also recommended crystallinewaterproofing.

Long available for industrial applications, crystallinewaterproofing is now used in residential applications. Itconsists of a dry powder compound of Portland cement, veryfine treated silica sand, and proprietary chemicals.Combining the product with water and applying it to thesurface of concrete results in a catalytic reaction that formsseveral inches of non-soluble crystalline fibers within the

pores and capillary t racts of concrete. This seals theconcrete against the penetration of water or liquids f rom alldirections. UGL DryLok is one of these products.Supposedly this will work in either cured papercrete or in thewet mix itself. It's pricey, but said to be so effective that it spossible to make ponds with papercrete. If it will hold waterwithout leaking, it should prevent water penetration.

Coating the outside of a papercrete roof with about an inch of Sprayed Polyurethane Foam (SPF) isanother approach. It is expensive, and not environmentally sensitive, but it may be a goodcompromise. I walked on this kind of roof in Prescott, Arizona, where the sun is very strong, andthere were no problems with it. It's tough, flexible and absolutely waterproof. With reasonablecaution, it can be walked on without worrying about puncturing it, though it is vulnerable to heavy


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This five year old papercrete workshophas a poured roof covered with steel

roofing.

Inside a shed with a poured roof. Twolayers of off set chicken wire hold the

slurry while it dries

A bedroom wit h vaulted ceilingof papercrete.

pointed objects. I t also adds an additional R 6.88 per inch of insulation to the roof. That is theequivalent of another three inches of papercrete. Add that R-value to two four-inch thick papercreteroof panels with mortar, and the total R value is about the same as the walls. That is a greatenvelope for a home, especially considering that the roof would weigh about eleven pounds persquare foot. At that weight, if a wall were supporting a 25 foot (7.6 meter) span of roof by itself(unlikely), the total load at the base of the wall would be about 550 pounds per square foot. That isa little less than four pounds per square inch. Since papercrete is variously rated at well above 100pounds per square inch, there is a very wide margin for wet snow or any other additional roof load.

Another approach to roofing in New Mexico was pouredpapercrete with a metal roof installed over it . This hasn'tleaked since the building was built five years ago.

POURING THE ROOF

Some people prefer to place wet papercrete directly on the roof rather than go through the processof making, cutt ing and fitt ing roof panels. This works fine for structures with nearly flat roofs. Ofcourse, a nearby source of water is required.

A layer of one-inch chicken wire is tightly stretched over theceiling joists or vigas of the structure and fastened in placewith heavy-duty metal staples. A second layer of one-inchchicken wire is of fset 1/2 inch f rom the first and installed thesame way. Ideally, the papercrete is drained on the groundand then pumped, augured or handed up to the roof inbuckets. Mike McCain has used a four-inch grain augur to liftpapercrete to roof heights. A number of people have writtenthat pumps are not reliable, but others have found ways tomake them work.

A few inches of papercrete are spread over the chicken wire,which sags somewhat under the weight. After it is allowed todry, a second layer of papercrete - and possibly additionallayers - are placed the same way. The unintended advantage to this method is that the papercretesags down between the ceiling joists or vigas thereby providing greater thickness and moreinsulation value. The down side is that wet material is heavy to work with. Of course, cuttingpapercrete panels is dusty, so it all depends on which method you like best.

After the roof is poured and smoothed out, the same waterproofingmethods can be used as those for roof panels described above.

Another way to go is to build a vaulted roof or domed roof out ofblocks right on top of the walls. See Domes. This method has been

done successfully, with beautiful results, in Texas by Clyde T. Curry.Besides saving the cost of the roofing framework, the domed orvaulted ceilings of papercrete provide good insulation.


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Short wall sections between windowswere screwed to window frames for

added stability.

Frameless glass can be embedded inpapercrete without fear of cracking.

Outside bottom is not covered to allowdrainage.

Screws are the anchor of choice forpapercrete.

WINDOWS, DOORS AND CABINETS

If windows and door are pre-hung in their own f rames, they can simply be screwed into thepapercrete opening. The gaps can be trimmed conventionally and/or filled with papercrete. I havehad success adding a small amount of Plaster of Paris to papercrete where it comes into contactwith wood. Mixed this way, the papercrete adheres very firmly to the wood. Before drywall, which isPlaster of Paris between sheets of paper backing, wood lath was nailed to studs and covered withplaster to f inish walls. That might explain why the papercrete/plaster mix works so well with wood.

If wood or metal f rames have to be installed, they can be

screwed directly into the papercrete. The opposite is alsotrue. At a construction site in New Mexico, I saw narrowsections of unsupported papercrete block walls, betweenfloor-to-ceiling windows, angle-screwed to the windowframes. The frames themselves were independentlyanchored to the floor and to the roof plate. This stabilizedthe short walls extremely well. Any gaps are filled withpapercrete and the inside surface of the wall opening (notcovered by the frame) can be surfaced with papercrete.

Papercrete has another quality, which makes it ideal forinstalling frameless glass. The glass can simply beembedded in the papercrete. Papercrete doesn't expand orcontract perceptibly, even when wet or frozen, so sheets of

glass or glass block can be embedded in and trimmed withpapercrete without fearing that they will be damaged byexpansion or contraction of the papercrete.

Windows and doors should ideally be insulated or the R-value benefit of papercrete walls and roof is compromised.Windows should be at least double paned, but that costsmore. It is easier to find cheaper, older single-pane windowsand unframed glass than newer multi-paned windows. Theolder windows have character and look more substantial.Since glass can be embedded in papercrete, so can severalseparate sheets of glass or two complete windows. The oneon the inside should be open-able for cleaning. The airbetween the panes is the best possible insulator, so if using two single-pane windows, space themas far apart as is convenient. In extreme climates, insulated doors or two-door entryways should bebuilt to minimize heating and cooling loss.

China cabinets, pre-built shelves, medicine cabinets andanything else, which has to be anchored to the wall can befirmly anchored with screws. Papercrete does not hold nailsany better than drywall, but screws work very well and willhold a considerable weight. The great thing about screwinginto a papercrete wall is that you dont have to look for astud. You can anchor any object exactly where you want it.

PLUMBING AND ELECTRICAL

Installing plumbing lines requires cutting holes and channels in papercrete. This is fairly easy iforiginal papercrete mix didn't have a surplus of solids (sand, powdered glass) or cement in it.Cutting papercrete results in a lot of dust. Consider wearing a mask or respirator. Holes andchannels can be made with conventional drills and a chainsaw. Once the pipes are soldered and


10/13

Papercrete stucco sticks to concreteblock very well. The lighter sample onthe left was mixed 50-50 by weight

with Plaster of Paris - the one on theright with 60-40 Portland cement.

One coat of inexpensive latex paintwithout a primer covered thispapercrete sample very well.

Foam and acrylic-based stucco overpapercrete.

pressed into slots in the papercrete, they are covered with more papercrete. The benefit is that theentire plumbing system is insulated. Cold stays cold and hot stays hot longer - less wasted energy.

Narrow channels for electrical runs can be cut with a circular saw or chain saw. To make holes foroutlets, cut horizontal and vertical slits with a circular saw. Then pry out the unwanted piece with ascrewdriver. One of our practitioners mentioned that he puts a glob of non-flammable mortar behindhis outlet boxes for safety, since most home f ires start where the wiring enters the outlet boxes.Outlet boxes can be angle-screwed directly into the papercrete. Once the electrical wiring andoutlets are installed and tested, the channels for the electrical runs are f illed with papercrete.

FINISH - EXTERIOR & INTERIOR

Exterior finish can be papercrete, stucco or a 60-40 mix ofpapercrete/stucco. Some practitioners use two sacks ofPortland cement and make their stucco the same way astheir blocks. Doubling the amount of Portland cement in thepapercrete gives it more strength and resistance toabrasion. One practitioner we spoke with uses six sacks ofPortland cement and paper- no sand or other components -to make wall plasters. He feels this is essentially what isbeing purchased when buying exterior stucco. Papercretestucco can be painted with exterior latex paint. I examined asmall home painted this way. The paint had been in place forover three years and looked like it had been recentlypainted. Papercrete stucco takes paint very well. Without aprimer, one coat covers quite well. For peace of mind, two orthree coats are advised. Rather than pay the high cost of aprimer or multiple coats of the same color paint, justpurchase latex paint that has been color-matched incorrectlyor abandoned at the paint counter. Most stores will sell it forabout four dollars a gallon. It is perfectly good paint, just notthe right color. All the different "mistakes" can be mixedtogether and used for the first coat or two. Then apply thecolor you want as the final coat.

Stucco adheres topapercrete walls very well with or without the use of stuccomesh. Andy Hopkins' house in Colorado has a texturedstucco coating, which feels like hard plastic. Andy has soldthe house so the type of stucco couldn't be determined. Itwas some kind of new foam and acrylic-based stucco. Thistype of stucco stuck to the papercrete very firmly, lookedgreat and was weathering fine.

Classic El Rey stucco was used on a shed visited in northernNew Mexico. This type of stucco is made with Portlandcement, and is colored all the way through - so a scratch ornick won't be easily seen. The shed was five years old andthe stucco was in nearly perfect condition.

Classic stuccoes and a number of new acrylic formulationsare available in many colors and textures. Some are quiteexpensive and some require an environmental premium.Keep in mind that papercrete stucco looks great and canwait until a better solution becomes available. Lime might beconsidered as well.


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Five year old El Rey stucco overpapercrete.

An adobe eart h f loor inlaid withflagstone.

Interior finishes include many of the same alternatives asexterior. One approach to interior finish was used in a largehome in Arizona. The owner covered all interior surfaceswith a thin layer of drywall joint compound. A few cracksdeveloped over time.

Kelly Hart has used a white lime wash, which is particularly attractive, in several rooms of his home.He also discovered a way to mix latex paint 1:10 with water to produce beautiful water-basedstains. His bathroom stain is particularly attractive. Stains not only dress up the look of thepapercrete, they also cut the cost and amount of paint used by ninety percent!

Lime wash on papercrete ceiling. A stained papercrete wall in abathroom.

FLOORS

Many people using papercrete prefer alternatives to concrete floors, because of expense andenvironmental issues. Papercrete itself may not be the best solution for floors since the pointpressure of table and chair legs will indent it - unless a great deal of cement is used. Onepractitioner we spoke with makes papercrete floors in yard quantities, about 200 gallons, with sixsacks of Portland cement and about 45 shovelfuls of sand. That provides a hard enough slab towork well with f loors.

Some people use papercrete as a sub floor to insulate the f loor from the surrounding earth andprovide a base for a radiant heating system.

An earth f loor made of adobe, or adobe mixed withpapercrete instead of straw, is an alternative. Earth floorscan be f inished and decorated in various ways. There aremany books available about building earth floors.

Another lesser-know option for floors is tamped road base.Road base, sometimes called "city base," is what is used formaking roads. Be careful. If you simply ask for " road base",you may get common ABC gravel with litt le else in it . Thetype of road base you need has a mix of rock, sand, clayand dirt in specified quantities approved by cities forroadbeds. In the Phoenix area, the material is called ABCMAG. The MAG stands for Maricopa Association ofGovernments. This is a consortium of cities in Maricopa

County where Phoenix is located, hence "city base." ABC MAG has a mix of under one-inch rock,sand, clay and dirt. This material is applied in several layers. Each layer is screened finer,dampened, screed, tamped and t roweled smooth. After finishing, the top layer should be assmooth and level as a conventional floor.

Successive screening is a lot of work. With some investigation it's possible to find out what theconstituents of the road base are. Buy them separately and dry mix them using aggregate sizesappropriate for each layer. This saves a good deal of labor.

The finished f loor is sealed with boiled linseed oil and turpentine. The entire process is described ina chapter called "A Tamped Road Base Floor" in "The Art of Natural Building."


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Road base can only be had in the colors of nature and the colors vary from location to location. Inthe Phoenix area they vary from gray to brown. In Austin, I'm told they are reddish. There areprobably ways to vary the color. An advantage to road base is drying time (which is much fasterthan adobe.) It only takes a few days in dry climates.

Road base costs under $5.00 a ton, if you pick it up. Working with it is easy - no mixing straw, clay,papercrete, etc. Two 12-ton truckloads cover 500 square feet. It is also very durable having aplasticity index (in Phoenix) of 0-5. The plasticity index is a measure of a materials' tendency to sag.Smaller numbers are better, but it 's common to see ratings of up to 12.

HEATING AND COOLING

This is where papercrete shines. With a papercrete envelope and well-insulated doors and windows,much smaller heating and cooling systems are possible.

In fact, with some planning, the heating system of the home can be built into the floor. Solarheated water is circulated though a serpentine system of plastic pipes embedded in the floor toproduce radiant heating. Since the floor has quite a bit of mass, the heat is retained for longperiods when the water isn't being heated, such as at night. Usually a small fireplace or electricheater can easily supplement the radiant heating.

Cooling costs are also greatly reduced. A much smaller air conditioner or evaporative cooler can beused. If you want to live comfortably off-grid, newer solar power systems are an option. The newhigh-tech systems are computer-integrated with wind-power generators and propane generators.On extremely hot or cold days, when quick heat or cooling is necessary, the new systemsseamlessly move to the generator. As soon as the demand falls within the supply parameters of thesolar or wind equipment, the system switches back to them. So fossil f uels are only consumedwhen peak demand requires. This kind of system is also modular. The initial system can be small ifyou are living in part of a structure while building the rest. As you add on to the structure, additionalmodules can be added to provide the increased capability you need. This is great because you don'thave to buy more capability than you need before you need it.

Living in Paper-construction

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