Step 4: Making Papercrete Blocks
Block molds- mine are made from 2x6's and scrap siding
Bathroom scale- for measuring out the paper
Paper (used of course)
Shredded plastic (if you want)
95 lb bag of cement (cement not concrete- no rocks or sand in the mix)
1. Set out your molds. You will need enough flat space to drive over them and pull your truck and the mixer in all the way in front of the molds.
2. Fill the mixer 3/4 full with water. I just eyeball it.
3. Put in the paper/plastic. I use about 75 lbs.
4. Add the bag of cement. You don’t need to open it, just toss it in.
5. Cover the mixer securely. This is very important. Just think of what happens when you have a blender top malfunction and multiply it by 100… I use a canvas tarp with a cargo strap.
6. Drive slowly- 5-10 mph for one mile. The mixer will chop up the paper into a pulp and mix it with the water and cement.
7. Empty the slurry into the molds. If you got the mix right you should be able to open the drain, fill some blocks, close it, pull forwards a bit, repeat. If the papercrete is too thick you've got some shoveling to do. The type of material you are using can make a difference too. Cardboard makes for a thicker, chunkier mix where newspaper is finer and smoother. Sometimes I use a plunger to force it through too. A lot of poop jokes get made here. Let your imagination run wild. I get about 45 blocks per batch.
8. Remove the molds. I do this right away. I want as much air flow around the blocks as possible to help them dry.
9. Wait a few days for the blocks to dry.
10. Stack the blocks under cover to dry further. I like to wait a couple weeks before using them.
11. Do it again and again until you have several pallets stacked with bricks and your year’s supply of paper trash is gone. That’s 10-15 batches for me.
Once you have a big stack of blocks It's time to build something. I've been putting up little buildings all around our place. Let's take a look at a yurt I built out of papercrete blocks.