THE NEW BUILDING IS COMING OUT EVEN BETTER THAN THE LAST ONE
I know I’ve been away from this blog for a while. I just can’t seem to coordinate my making papercrete with the filming and writing about it.
But it’s been a busy and productive 2 months in spite of the strong winds and cold weather.
The trench is about a foot deep and filled with 3/4 + gravel. This is a rubble trench foundation developed and popularized by Frank Lloyd Wright
I had a few glitches at the start such as my neighbor throwing a fit that I was starting a new building within sight of his house. After a few heated words I agreed to move it to a place more acceptable to him. I had already dug the footers ( a 3 day job) so he agreed to hire a guy and between the 3 of us we got the new trench dug and filled with gravel in a days’ time.
One idea that is working out very well is the design for the forms.
Vertical forms are in place and plumb. First horizontal form is set at bottom of wall.
I decided to set up forms so I could slip form the whole building in one continuous course at a time. What I mean is that all the slurry is poured all the way around the building with no partitions. This way there will be no weak spots where the finished papercrete will pull apart.
All the vertical forms are made of two 2 x 4s separated by a short piece of lumber going through the wall at the top, middle and bottom. End forms are made of 2 x 4s with a solid piece of plywood from top to bottom. This way the slurry will flow all around the walls and corners with no breaks. After all the pouring is done and the papercrete has set up all of the forms will be removed leaving just the strong papercrete walls.
Everything is in place. As soon as the ball pops out of the exit pipe the slurry will flow out quickly. I use a wet mix for this reason.
We were able to pull the mixer right up to the forms for the first pour. Notice that the gravel is in place and has been brought up to meet the bottom of the forms. This keeps the slurry from escaping under the forms. The ball is ready to pop out and once it does the slurry will flow easily.
The first two courses flow all around the building with no breaks. I added latex paint to the mix to help it resist water.
My newest helper, my daughter Eliza on the scaffold pouring slurry.
This shows how we set up our scaffolding with saw horses and planks. The steps from an old mobile home make it all work smoothly.
The first two courses have been poured. This picture shows the 4 foot opening for the door. These courses flow uninterrupted around the entire perimeter of the building ensuring a strong foundation for the rest of the walls. The solid forms at the sides of the doors will be removed after the papercrete has set up and the opening will be cut to the exact size needed for the 6 foot French doors. When we get above the door opening the walls will again be uninterrupted around the whole building.
After we got above the first forms we had to use buckets to get the slurry into the forms. We were able to set up a great scaffold system with saw horses and planks. It goes all the way around the building so one person ( or more) can be on it while others fill buckets and set them on the planks.
I’ve found I don’t work as much alone with the slip forming method. It just seems unproductive to labor alone all day and get only one mixer load done when I can wait until the weekend and have help. With just one or two extra people the job whizzes right along and we can get up to 4 courses done in a few hours.
As of now the walls are half way up. The plan is to finish these walls to the 8 foot height and let them cure for at least a month. In the meantime I will close in the roof on the first little building, put a floor in it and peel the vigas for this building.
Next time I will explain how I am using blocks I already have to fill in the slip form walls.
About The Author
Glad to see you up and running with this big, inspirational project at last.
It looks good, too.
Can’t wait for your next post.
Michael
Hi! Nice blog and great project! I haven’t really seen much use of the poured wall method in papercrete building, and as I read your blog a big question mark keep popping up in my head: What about shrinkage? I know papercrete blocks suffer from some shrinkage (depending on the water content in the slurry) but in the case of blocks this would not cause a major problem. However, if you are slipforming walls, wouldn’t shrinkage cause stability problems? Or do you solve this by keeping the slipforms on the lower courses and just have the slurry fill up the cavities formed by the shrinkage, thus bonding the two course together?
I’m at a loss when it comes to how you deal with shrinkage, please enlighten me! Your method seems so much easier than making blocks and then then having to deal with the masonry part.
Best regards, a Swedish fan of your blog.
You’re right that shrinkage is a problem. I had an especially hard time with it on this project because the pumice I normally use has been unavailable. What happens is that the slurry that is poured into the forms shrinks away from the sides of the forms leaving a gap at the bottom of the form. The next batch flows down and around the previous one filling in the gap. If it is a thin batch it falls right through so I have to be careful to have the right consistancy. I think this does bond the courses together.
I have noticed that the small building I did last fall is settling and some cracks have appeared at the top corner of the door. I am just going to let it continue to cure and settle and then patch it before I do the plaster. The building I am working on now is a lot better quality that the first one so I don’t think I will have much of a problem.
I will say that I am much happier with the slip form/block method than with the straight block method. It is easier and faster and the end result looks a great deal better.
Also, I am so happy to have a note from someone in Sweden. I dog sat for a friend this weekend and she had one of Steig Larsson’s books there so I started reading it. WOW, I couldn’t put it down. I do need a map of Stockholm though. There are so many references to streets and areas of the city.
Thanks so much for the lovely email. I’m glad to know someone is getting something out of the blog. I know I should write more and notes like this motivate me.
Thanks for the quick answer! Yes, I can imagine how you do it. That means rather than slipping forms up, you just leave them to compensate for the shrinkage problem? Wouldn’t that create a bonding problem between the first pour and the second pour (and possible third, forth pours)? I realize you are only doing a one story building but still, I would be nervous about the strengths of those walls. Perhaps you compensate by over dimensioning the load bearing elements such as wall timber?
Yes, I am from Sweden and my old office is in the same block as Stieg Larsson’s old office! I don’t know if I ever saw him around though. I can see how all the names of places and people must be confusing for non-Swedes (I think Hollywood and US TV and literature works hard to keep names to a minimum).
Apparently there’s a map you can buy that gives all the locations in central Stockholm.
You should def. write more and add plenty of pictures! Blogs like this are a gold mine for alternative builders/makers all around the world! I have read so many papercrete building blogs that just refuses to work with slipform walls, I was quite surprised to see yours! Personally it won’t help me much, but a discussion on the climate, rain and soil/ground characteristics would be very interesting as well!