How to Build with Papercrete

Papercrete is a building material made from Portland cement, sand or other aggregates, and paper. It’s a relatively green building material, because it generally uses recycled paper, and lasts for a very long time. It’s also a good insulator due to the high paper content. The percentage of Portland cement by volume is much lower than in conventional concrete structures, which further adds to its eco-friendliness. Papercrete homes can be finished to look much like traditional stuccoed houses, and can be used for both traditional home designs (with modification for thicker walls) as well as for more organic buildings.

Instructions

Difficulty: Moderately Challenging

Things You’ll Need:

• Newspaper (lots of it)
• Sand
• Portland Cement
• A papercrete mixer
• Additional Building Materials such as windows, doors, flooring, roofing, etc.

1. Design your papercrete house. Remember that papercrete walls are typically 12” – 24” thick, and therefore have to have foundations that are designed to support walls of that thickness (concrete slabs are often the easiest foundation design to use with a papercrete house, and also the most cost-efficient). You may wish to enlist the help of an architect or engineer. Often you’ll need their approval on your building plans in order to get a permit. Also consider whether you’ll be able to have load bearing papercrete walls in your jurisdiction, or if you’ll need to have a separate roof support structure with papercrete “in-fill”.
2. Go to your local building authority with your plans to get a building permit. Depending on your local zoning and building permits, this may or may not be easy to do. Again, getting an architect or engineer to sign-off on your plans may be helpful or even necessary in your area.
3. Once you have your building permit in hand, you can start your site work. A foundation is the first thing to take care of. If you’re pouring a concrete slab, you may be able to do this yourself. For most other types of foundations, you’ll probably want to hire a concrete contractor unless you have prior concrete experience. Make sure that whatever type of foundation you put in that you have rebar protruding from the top on which to attach the papercrete.
4. Start acquiring your materials. You may be able to get newspaper for little or no cost from your local recycling center. You may also be able to find some by asking around. Portland cement and other your other materials will probably need to be purchased from a building supply store.
5. Build a papercrete mixer. You may want to consider an axle mixer (built from an old car axle that you can tow behind another vehicle) or some other type of bulk mixer. You can make small batches using a drywall stirrer and a high-torque drill.
6. Decide whether you’ll be pouring your walls in place or making papercrete blocks. Papercrete blocks may be easier to handle, but will probably take a bit longer than pouring in place. Create your forms for either the entire walls or for your blocks. Your block forms can be reused for making multiple batches. The materials for wall forms can be probably be reused to build additional wall forms.
7. Mix your papercrete. Use the mixer you built previously. Make sure that you soak your paper in plenty of water before you add your concrete. Also make sure that your batches are consistent so that your papercrete all has the same consistency, strength and weight.
8. Start pouring your walls. If you are pouring them in place, make sure that they bond well to the rebar coming out of your foundation. If you’re using blocks, you’ll need to drill holes for or otherwise accommodate the rebar.
9. Make sure to leave holes for windows and doors.
10. Once your walls are up, it’s time to put on your roof. Your roof can either be made from papercrete (with or without waterproofing) or you can build a conventional roof.
11. You may choose to waterproof your papercrete or not. The choice for the most part is yours. If you live in a particularly wet climate, you may want to go ahead and waterproof, especially if you don’t have generous roof overhangs. Commercial concrete waterproofers are the most commonly used waterproofing agents, but can be costly.

Tips & Warnings

• Try small test batches with different formulas to find that one that suits your needs. You can use a blender for test batches, but if possible, buy a cheap one specifically for this, since you may wear it out.
• Newsprint works best for papercrete, but virtually any paper will work, even glossy magazine paper.
• Use salvaged building materials for your windows, doors, flooring, etc. to keep costs down.
• Cement is caustic and can actually burn you if you’re exposed to wet concrete for long periods of time. Make sure you wear gloves when working with cement.
• If you're not familiar with building or with building design, consult professionals or people you know who do have experience to prevent costly mistakes.