Teresa, I know you have check out the archives and/or been keeping up with the stream of posts for awhile, I would like to mention (if you haven't already seen) the posts and pictures of Doris and Rons project. I've seen this building and it is really something to see, they also have a great roof system. If you are interested do a search and check it out, they spent some time in relating how the project was done in their posts and pics.
On Sun, Nov 7, 2010 at 6:20 AM, Spaceman <Spaceman@starship-enterprises.net> wrote:
Who started the idea that pc is not load bearing? PC has a compressive strength of 300-400psi depending on your mix, and every foot of 12" thick wall will support over 20 tons of weight. PC will support a lot more weight than a frame wall. PC's weakness is in tensile strength so you shouldn't make a beam from it, though I have seen that done successfully.
There are a lot of theories flying about, from people who have thought about making pc but have not yet done so. Those who have actually built something with pc have a better idea of what is possible. Look at Judith's projects, there is no steel anywhere in her buildings. The pc walls do indeed support several trees (vigas) and a ton or two of papercrete on top of that. No rebar, no posts. There is a bond beam around the top made from more vigas, which may or may not have been necessary in this case.
spaceman All opinions expressed or implied are subject to change without notice upon receipt of new information. http://Starship-Enterprises.Net
On 11/7/2010 1:59 AM, Teresa P wrote:Excellent post! This and the other one! The more I have been learning about pc, the more I am thinking it wont be appropriate for load bearing with a rectangle building (however, maybe with enough cement?) Im also looking into maybe doing a hybrid. With the hybrid, I would have L corners that were rammed earth (or maybe earthbags with barbed wires), the corners would be about 3' long and then do pc for about 4' and then re for 2' and then pc for 4' and continue in this pattern down the length of the wall to the next corner which would have 3' L re. The door jambs and windows could be done with wood where necessary. The foundation would be rubble in the wire cage you suggested with a concrete or wood beam at the top running the length of the wall. I am going to have to stabalize my silty sand though no matter if Im working with the re or pc or earthbags. Im a little concerned about the pc sticking to the re or earthbags though. Judith mentioned something ab out that as well... I do know the re and the earthbags, with cement added, are load bearing but truthfully re does NOT sound like fun with all the tamping (especially around verticle rebar) and earthbags depend so much on the strength of other earthbags tied together that Im not so sure making columns of them is the wisest choice especially in an earthquake zone. Again, I LOVE the pc but sure wish it could be made load bearing in a rectangular structure without the use of wood. --- In papercreters@yahoogroups.com, Forrest Charnock <fpcharnock@...> wrote:If one wanted to build a load bearing wall one way that would work very well is to build a modified slip-form. To do this you have to have a proper concrete foundation which need not be a slab although there is an advantage in the slab as it could be topped with papercrete or a clay sand mixture ,paper adobe etc, As long as the concrete slab is properly reinforced, mixed and cured no reinforcing is needed in the topping layer of paper-adobe orwhatever insulating soil or paper-soil layer you choose. As far as doing this cheaply it is hard to beat using papercrete blocks and build the frame with small quartered trees for corner post and rough cutposts or poles for uprights with 2 flat sides and sawmill planks with small spaces between them to tie the papercrete blocks on the inside to those on the outside or you use bigger blocks outside and plaster inside , The tree and sawmill plank frame is structural and the papercrete blocks insulation. Interior walls can be done with small trees flattened on 2 sides and 3 at door and window openings. All of these cuts can be made with chainsaw jig you can build yourself if you have the skills and access to the tools You still need a strong perimeter beam to hold the weight. If the soil is relatively stable as far as moisture content money can be saved by building a trench wide enough to accommodate large bags filled with stabilized soils and or gravel , crushed concrete, river rock etc, at a right angle to the perimeter beam below the frost line. To make the foundation incredibly strong for not too much more you can pour a 4 inchslab over the bags {on a level sand layer of course} and then backfill over it. The excess soil can be used elsewhere perhaps as an insulating paper-adobe layer for the floor. Then set your forms and pour the concrete perimeter beam on top of the bags, You do the same for the interior walls but no where near as big and you can use smaller bags. The interior wall beams form a grid that stiffens the perimeter beam immensely. To make the slip form wall load bearing the same method is used for the foundation unless of course you want to build a slab . In case you don't know what a slip-form is it is a method of wall building using concrete forms to build poured concrete walls in increments. The forms are placed on the perimeter beam and the reinforcing material {usually re-bar} set in place and the concrete poured to the top and troweled and vibrated in andleft with a rough finish with the re-bar sticking out . After the first course is cured sufficiently the forms are "slipped" off and sat on top of the first course and the process is repeated to the desired height. They are custom made on site usually and require only basic carpentry skills and tools to produce . They are wide enough to accommodate the desired wall thickness and from 2.5 to 3.5 feet high in most cases, The advantage of this method is it allows one to pour an immensly heavy wall with all thewonderful thermal sink qualities with a set of forms that is far cheaperand , much easier and much safer to use than attempting to build a highand heavy wall all at once. Another advantage is that you can lay stones, coke bottles sealed together to allow light in , cord wood or just about anything else you can imagineright inside the form and temporarily attached to the outside of the form before pouring the walls. Some of the most strikingly beautiful homes I have ever seen {to me anyway} were built this way. They were also immensely strong . To make a papercrete wall structural you need to get an engineer or architect to to check the plans or draw them in the first place. Basically there are 2 methods I can see to accomplish this. The easiest way would be to use steel beams or posts for the uprights and steel or wood or even aconcrete beam for the top plate . The least expensive way would be to usepaper forms similar to those used to build the giant pillars that supportbridges and highway overpasses but of course much smaller. The re-bar is left protruding from the foundation beams . Re-bar is then inserted intothe the paper forms which is then tied to the protruding re-bar sat on top of the beams The rest is fairly obvious but you really need to pour the concrete supports all at once and let them cure a few days before continuing, This method would be a lot of work in one regard but on the other it offsets the tedious work of making and laying the blocks . It would be an extremely well insulated house with great thermal sink qualities as well due to themass. The first layer would be conducive to using a mixer and then pouring directly in to the form and if you had access to a fairly heavy pickup or a bobtail and a way to lift the mixer on to a wooden platform in the bed you could get the second but after that you really need a pumper. Perhaps the local concrete could mix and deliver it to the site ? If that is not feasibly you could rig up a simple pole on a tripod and use it to lift buckets of mix into the form or just stand in the pickup bed and use a bucket. There are small concrete pumpers that can be towed with a pickup .. I used one a long time ago to "snow top" roofs" . It would work perfectly for papercrete but maybe not for the concrete support posts with the aggregate I just don't know. Snow Top was a mixture of Portland, sand , and latex paint {white obviously} that was pumped up on top of hot tar roofs. It was real popular in Houston Texas 30 years ago because it made ugly roofs beautiful and reduced the temperature of the roofs from third degree burns and poorlittle dead sparrows to cool enough to walk barefoot on the hottest day in August and in Houston that is hot! That is how I sold them . Every time I did one I invited the neighbors who had built up roofs to come look at their neighbors beautiful new roof and I would walk barefoot on it. The demonstration was convincing. Sadly other contractors misrepresented it and told people it sealed the roof . worked on shingle roofs and that it was permanent. The fellow I worked for told them the truth that you had to seal the roof first and re-coat it in 3 to 5 years. Sadly he decided to sell the machine without telling me for 1000.00. That would be 2000-2500.00 today but it was a bargain. Anyway if you could find one of those it would not only pump the papercrete it would mix it as well . It came with a giant paddle mixer like the ones at a commercial bakery for giants. Sorry for the long post . One more detail: dried bamboo poles would make excellent reinforcing for the papercrete . Ben Franklin used it to build his swimming pool. -- Forrest Charnock------------------------------------ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/papercreters/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/papercreters/join (Yahoo! ID required) <*> To change settings via email: papercreters-digest@yahoogroups.com papercreters-fullfeatured@yahoogroups.com <*> To unsubscribe from this group, send an email to: papercreters-unsubscribe@yahoogroups.com <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/ ----- No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1144 / Virus Database: 424/3230 - Release Date: 10/31/10
--
"If you give yourself fully to this moment the next moment will turn out just right."
- Sequoyah Trueblood
__._,_.___
Your email settings: Individual Email|Traditional
Change settings via the Web (Yahoo! ID required)
Change settings via email: Switch delivery to Daily Digest | Switch to Fully Featured
Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe
__,_._,___
