Biochar Gypsum Plaster

A while back I spoke with my friend Uncle Mud about plasters. Somehow gypsum plaster came up. I enjoy using natural materials and know that the environmental impact is much lower when I take a shovel out to harvest my own materials from the land. Sometimes, a project really just needs to get done. So I began to test myself to discover what my building values were at the time. The curious monkey with a limited timeline won out.

I went out and bought some gypsum plaster (joint compound). The ingredients are still pretty natural, however I'm sure the processing has a higher impact. My other best option for this project was biochar lime plaster.  

Because I buy the sand from a local quarry and mix the plaster myself this cuts down on impact for lime plaster manufacture, but also requires a lot more time on my part. I am still unsure what the differences in impact are for processing of the hydrated lime versus the gypsum plaster are, but I haven't yet marked on my calendar some time to look into this ;)

The short story is, I feel I'm cheating a bit, compromising, but I'm also thankful to save some time and curious about the finished product. 

Biochar gypsum plaster instead of biochar lime plaster

If you have never worked with lime plaster before, then you should know it requires a little babying. The gypsum plaster really does not require babying, it is very user-friendly. 

I took my biochar and ground it in the blender until it was very fine, then mixed it with the gypsum plaster. It was easy and quick. After troweling it on I went back over to play with the texture and check out the thickness. 

In my first attempt I tried my friend's suggestion to add temepra paint for a beautiful color.  I added 2 cups to a small bucket. The color turned out a baby blue when dry. I decided it looked a little too artificial for me and went back over with one more time with just the plaster mixed with biochar.  Of course I love the tint that biochar gives. When damp the plaster is bluish, and it is speckled with larger black pieces if not ground too uniformly. 

Biochar is said to reduce humidity.  From my experience so far it does make a big impact.  Our house is in-ground. We have had to be careful of mold during certain seasons. So far, the rooms with biochar plaster on the walls have not had a problem with mold this year, though on a particularly rainy week we did find some mold in rooms that have previously been much less humid.  Now I want to plaster every wall with biochar.  Biochar can block certain waves and frequencies, though, so I am being selective to not block my wifi signal. 

On tinting with tempra:

I have seen some beautiful plaster tinted with tempra. From what I have read, a richer color may be reached by starting with a coat of plaster, then watering the plaster down to a paint consistency and adding the paint to this. The color then is painted on over, almost fresco style. I have yet to try this, and may soon do this with natural pigments. 

This is two coats over cinderblock. The lighting is a little strange in this picture, but the color of the plaster is uniform. I went for a bit of a scratched rugged texture, because I like my walls to make me feel like I am in a cave. The picture does not show a lot of detail, perhaps I will add a better one later. 

Lime plaster is much more durable, but definitely something I would recommend learning hands-on from someone who knows what they are doing. If you live in a warm, humid climate however lime plater becomes much easier. I found with my lime plaster that it is very important to keep it moist for a period of time, and ensure it is kept warm, with limited temperature changes to make sure it does not crack.  With the gypsum plaster, however, very cold temperatures will still cause cracking. 

This pre-made joint compound is a no brainer. Adding the biochar gives great benefits to air quality and humidity regulation, as well as adding a bit of carbon sequestering you can feel good about a small step to help with climate change. 

I like this mix. It was easy and I personally like the look. The biochar helped reduce humidity in the bathroom. When I want to work quickly I will use it again.  Still, I prefer the stone-like quality of lime plaster when I have the energy and time. 

Next time I may try a top coat of painted-on natural pigments mixed with plaster. 

Biochar plaster

I fell in love with earthen plasters during my cob course. It is nice to have a building material that you can wash out on the ground right next to your garden. It is nice to know what is in your home is not toxic to anyone, and the production of it is not creating any toxins elsewhere in the world.

It is nice to be able to source materials locally, to dig up my materials from the ground. This is much more affordable as well.

I have worked with clay based plasters and lime based plasters, and recently was introduced to biochar plaster. At the Ecovillage Training Center at The Farm in TN, Albert is the biochar man. I have to admit a little skepticism when first introduced to the concept of biochar, but there are so many people who report amazing results that I am sold. 

Recently the permaculture apprentices at the Ecovillage Training Center applied some clay based biochar plaster in The Prancing Poet (event space).  Albert mentioned that the biochar blocks electromagnetic radiation such as those that come from computers, microwaves etc. I was curious so I looked around and found a very interesting article on biochar plaster. 

Biochar as Building Material for Optimal Indoor Climate

by Hans-Peter Schmidt

The article mentions that biochar plaster is being used to restore old wine cellars. It regulates humidity for the wine, helps stabilize the temperature, and filters the air. 

I had yet to complete a final plaster coat on the cob bench around our woodburning stove, so I decided to do my own experiment.

I chose to use a 50/50 lime and masonry sand mix. with at least 20% biochar. The biochar was beautiful when wet, bluish-black. As lime plaster does, the biochar mix still smoothed into a nice finish after burnishing, looking almost like stone. 

I did have to baby the plaster a bit because humidity was low in the cold air, and I wanted to keep the cob at an ideal temperature for lime plaster curing so that I did not get large cracks (the last lime plaster I did was in ideal humidity and temperature and did not require water spritzing regularly as this mix did).

The plaster turned out great. I head to leave and come back to the Ecovillage Training Center, so I asked my husband to continue to spritz it for a week and keep an eye on it, then slowly decrease frequency of spritzing while it cured the our cold temperature with the stove running. I am very curious of the effect of the humidity regulating biochar on the lime plaster, but would need to try the plaster in different conditions to know that the change was related to the biochar in particular. 

I hear it is doing great and am looking forward to further biochar plaster on the walls. I will be keeping an eye on summer humidity in our home. I am looking forward to some changes in this!

Next time: More fibers, try a natural tint, do this plaster when it is warmer out!

Mosaic story floors

I started tiling last year when Sarah Haas came through and showed me what she leaned with Dan Phillips, other tilers, and then through trial and error of her own professional tiling efforts. She showed me how to tile with commercial thin-set mortar and grout with scrap tile. I decided that I wanted to complete the stairs with scrap tile and bottle caps. 

This year I started a new project involving bottle bottoms. I cut the bottom off of beer bottles with a tile saw and mortared them in.  To strengthen the bottoms (even though they are pretty flat) I filled them in with mortar as I set them. 

As always I had to try new things. I started with the thin-set mortar for tiles, but remembered how easily some of the tiles on the stairs had popped out pre grout. Instead, I grabbed a bag of premixed brick style mortar.  Once dry these tiles were not going anywhere. Thin-set mortar allows future changes if you may want to scrape everything up and try again, but after this much work with mosaic, I can't imagine wanting to redo the floor. 

I then mixed my own mortar for a bit, with local masonry sand from the quarry and a bag of portland cement. I found with this that sometimes there were still small pebbles that would make an uneven setting for the tiles and they would pop out. Next time I use this sand I will pre-screen.  Darrell, a contractor staying at moonCat right now, brought a bucket of fine sand scooped from a local property. Even though this contained a small amount of silt the mix held great, and this was my absolute favorite, until the cats found the bucket and made it into a litter box.

I did consider using an earthen plaster of clay, sand, starch, matrix material (such as straw, manure, etc.) and water. I decided against this because the house is in the ground. If by chance flooding occurred, I would need to redo the natural plaster and tile. With the amount of time I put into mosaic work, I think I will seek sustainability by using materials that will not need to be continually consumed, but will last for a long time (use of portland cement instead of natural plaster).

I did start with commercial grout, and decided to end with commercial grout, but recently spoke with a friend about mixing my own. My friend Michael (that I met at Earthships) recommended a fine sand mix very similar to the actual mortar I was making. He said mixing in the structural poly fibers used for cement may help prevent cracking. I may play with adding lime to the grout as well. At The Farm Ecovillage Training Center I had seen that the home Albert Bates was staying in had bottle caps laid in a lime plaster, but it did not hold well. Perhaps a mix of some portland and lime . . . and a little soaked sawdust?

I prefer to use natural or "waste" materials when possible. With this floor I used scrap tile from a mix of other contractors, the Habitat For Humanity Re-Store, and bottles and bottle caps that were being thrown away from local bars. I will admit that on one dark and frustrating night I decided to "Just finish it quickly!" by laying actual square tile bought from a store and did buy a couple of boxes of cheap tile.

I have come to realize that my tiling values include local material sourcing and waste/recycled materials as much as possible, but also there is a measure for my time and effort. I wanted to make the tree much larger with the bottle bottoms, but this is very time intensive.  I pushed myself for long days to complete the mosaic tile quickly and used all of my great TFH kinesiology pain releasing techniques to support days of statically bending over and mortaring in bottle caps and bottle bottoms. The tile portions go very quickly and are not quite so static. 

I can thank craigslist, local bars, and local flooring contractors for most of my tiling material! Thanks to Phoenix for all of her help placing bottle caps, and WWOOFer Chris Burke for hours of helping me to cut bottle bottoms.

I really enjoyed this project and have found it very rewarding. I am looking forward to more! As little girls at moonCat plot about who will own the house when I die I feel that my mosaic story floors can promote inspiration, creativity, culture beyond my lifetime. 

Farm Tour

This past Saturday we hosted a farm tour at moonCatlife. Jerome showed everyone around our beginning food forest and I took a turn showing building and retrofit projects. Phoenix showed everyone the kittens. I enjoyed making some new friends in the area. 

I have been hoping to project some movies in the barn and one of our visitors just so happened to have an old screen lying around. After connecting with a belly dancing instructor I am hoping to get some lessons going here along with yoga and meditation.                                   

We walked on our new paths that Darrell spent so much time mulching and looked at the new apple trees. The apple area also has a mix of herbs and some transplanted gooseberry bushes and wild grapes. I wanted to try a couple of hardier pecan and almond trees in this area as well so we planted them here.

The apples were planted next to a group of trees that grew over a large strawberry patch. There are mulberries, more wild grapes, rye, and some asparagus as well as other wild edibles of the area such as wood sorrel, lambs quarters, and milk weed (pods).  Clover and medic are growing throughout fixing nitrogen, drawing bees, and smelling wonderful.

This year Jerome has added a couple of pigs to our permaculture system and they are clearing the land for planting in our "pig tractor".  I added some swales for redirecting rain water.  We planted larger willows to boarder the farm that should have more stamina than smaller starts from the past. A path is in progress next to the willows now.

We enjoyed sharing knowledge and learning more tid bits about wild edibles and other natural ways of living from those who came.

 Here's to friends, nature, and innumerable possibilities.

Excavation

This past weekend some friends came out to see the place and help at the farm. They planted oak trees on the north side and we had a bonfire. Thank you! We didn't quite get around to pounding tires. . The next day we had a local, Jean, come out and excavate around the house. We are going to retrofit for our thermal wrap (earthship uber insulation from earth-rammed tires and foam insulation combined)!

The Earthship books talk about some retrofitted building experiments heating up just from a laptop or body heat in the winter. We are beginning to plan for some cooling earth tubes as well. We got the west, north, and east sides excavated and weatherproofed with plastic and something like tar. The greenhouse goes on the south side, eventually.

Plastic may not be the most sustainable product but, one step at a time. A house bermed into the earth will save many things but may be susceptible to water in areas with a high rainfall/water table (as we have already experienced with this moldy house). The plastic will help protect our time investment and resources as a water barrier.

We re-routed the gutters to rain barrels (scavenged large containers from around the farm) for watering the plants, and just to keep the water from falling right next to the house. Then we washed the grime off and went out to a nice dinner for our six month wedding anniversary!