Papercrete keeps coming up in off-grid circles because the raw material is mostly waste paper, it's light to handle in summer heat, and it insulates to some degree. It is not a structural concrete replacement, and it does not have the building code approvals that brick, block, or poured concrete carry. This article sticks to what papercrete actually does well: small outbuildings, garden walls, furniture, infill panels, sheds, and cold frames in low-load situations.
If you're after a structural wall system for a habitable dwelling in Australia, talk to an engineer and your local building certifier before you commit. Papercrete in a load-bearing role is not something you wing.
What Papercrete Actually Is
Papercrete is a cementitious composite made from shredded paper fibre, Portland cement, water, and optionally sand or clay. The paper fibre acts as both a lightweight filler and an insulator because air is trapped in the pulp matrix.
The standard volume mix is roughly 60% shredded paper, 25–30% Portland cement, and 10–15% optional sand, with water added to bring it to a workable slurry. Portland cement is the most expensive component by far, while the shredded paper makes up most of the volume and can be sourced free if you have the storage.
| Component | Typical share (by volume) | Notes |
|---|---|---|
| Shredded paper | ~60% | Newspaper, office paper, cardboard (uncoated) |
| Portland cement | 25–30% | The structural binder; the costly bit |
| Sand or clay | 10–15% | Optional; improves density and workability |
| Water | As needed | Enough to form a slurry that holds shape |
Why It Appeals to Off-Grid Builders
A few properties make papercrete useful where a full concrete pour is overkill.
- Lightweight. Papercrete is much lighter than concrete or adobe, so it is easier to handle, mix in small batches, and place without heavy equipment. This matters when you're working alone or with one helper, and it reduces the load on whatever footing you build it over.
- Thermal performance. Because air is trapped in the paper fibre pulp matrix, the material provides some thermal insulation, keeping buildings cooler in summer and warmer in winter. Don't confuse this with a published R-value — there isn't a universal figure — but in practice a papercrete wall feels noticeably cooler to touch on a 38 °C Central Queensland day than a concrete block wall does.
- Low-cost feedstock. The paper side of the equation can be free if you've got a source. Office paper, newsprint, and cardboard offcuts from a small business will keep you going for a long time. Cement is your only meaningful cash outlive.
Where It Works Well
Papercrete is suitable for:
- Exterior and interior walls (non-load-bearing or low-load)
- Garden sheds and storage units
- Furniture (benches, outdoor seating)
- Raised garden beds
- Cold frames and small animal shelters
These are all situations where the wall isn't holding up a roof load, the spans are short, and a small failure means a small repair.
Where It Doesn't Work
This is the section most promotional write-ups skip. Papercrete has real limits, and you should know them before you commit.
- Load-bearing residential walls. Papercrete is not a code-approved structural material for housing in Australia. Treat any claim that it is with suspicion.
- Moisture-prone locations. Papercrete absorbs water. Standing water, splash zones, and below-grade work are all out.
- Long, unsupported spans. Anything that wants to flex will crack papercrete.
- Fire separation walls. Papercrete contains paper. It is not non-combustible.
Specs and Requirements
Materials
- Paper. Newspaper, plain office paper, uncoated cardboard. Avoid glossy or coated paper — it resists water absorption and won't bond properly into the slurry.
- Cement. Portland cement, Type GP (general purpose) in Australia. One bag is enough for several small batches.
- Sand. Optional. Builder's sand or washed sand, 10–15% of the dry volume.
- Clay. Optional alternative to sand for a denser, more adobe-like finish.
- Water. Clean fresh water. Dam or bore water with high salt content will weaken the cement bond.
Tools
- Soaking tub (a 200L drum cut in half works)
- Paper shredder (or a chipper for bulk paper)
- Mixer — a paddle mixer in a 20L bucket for small work, or a small concrete mixer for larger pours
- Moulds — formwork timber, plastic tubs, anything that holds shape
- Trowel and screed
- Respirator, eye protection, gloves (see Safety below)
Mix Ratios by Volume
Common ratios reported in the literature include 3:1:1 (paper : cement : sand) as a starting point. Treat any ratio as a starting point and test small batches before committing to a wall.
Step-by-Step: A Small Block or Panel
1. Shred the paper. Aim for confetti-sized pieces. Long strips tangle in the mixer.
2. Soak overnight. Place shredded paper in water overnight to soften the fibres. This makes blending far easier and gives a more uniform slurry.
3. Drain excess water. You want wet pulp, not a soup.
4. Add cement. Mix paper and cement first, dry, until the paper is coated.
5. Add water gradually. Bring it to a thick, workable slurry that holds its shape when squeezed.
6. Optional sand. Fold sand in last if you're using it.
7. Pour into moulds. Tamp or vibrate to release trapped air pockets.
8. Cure. Cover and keep damp. Papercrete is typically cured for 24–48 hours before demoulding, with full strength reached within about two weeks. Keep it out of direct sun and wind during curing to avoid surface drying while the core is still wet.
For a wall, build a footing and place a damp-proof membrane before you lay blocks. This is standard practice for any masonry-like wall and prevents capillary rise from wicking water up into the paper fibre. A 100mm concrete strip footing is plenty for a single-storey non-load-bearing wall on decent ground.
Finishing and Weatherproofing
Raw papercrete will absorb water. Plan a finish from day one:
- A lime render or cement render on the exterior face
- A waterproofing paint rated for masonry
- Wide roof overhangs to keep rain off the wall
- The wall should never sit in ground contact — keep the base at least one brick course above finished ground level
Internally, papercrete takes paint, lime wash, and plaster once fully cured.
Durability and Lifespan
Honest answer: there's no universally accepted service-life figure for papercrete in the published literature. In practice, papercrete walls that have been rendered, kept off the ground, and sheltered by a decent roof have held up for decades. Walls that have been left raw and exposed to weather haven't. The render and the roof overhang are doing most of the work.
Common Mistakes
- Skipping the soak. Dry paper won't blend. You'll end up with cement clumps and dry pockets.
- Using coated or glossy paper. It won't absorb water and won't bond. You'll get a crumbly mix.
- Too much water. A runny mix is weak. Aim for wet pulp, not slurry.
- No damp-proof membrane. Capillary rise will wick ground moisture into the wall and the paper will rot.
- Building without a roof overhang. Direct weather exposure destroys papercrete.
- Skipping PPE. Dry cement dust is alkaline and unpleasant. See Safety.
Safety
Working with cement-based materials means dealing with alkaline dust that irritates skin, eyes, and lungs. The dust is the main hazard, not the paper.
- Wear a respirator (P2 or better), eye protection, and gloves when mixing or handling dry cement.
- Long sleeves and closed shoes are basic PPE for any pour day.
- Work in a ventilated area or outdoors.
- Wash skin promptly if wet cement contacts it — wet cement is more caustic than dry.
- Moulds under load can fail. Brace formwork properly before pouring.
When to Call a Licensed Professional
Papercrete crosses into regulated territory the moment it touches any of the following:
- A habitable dwelling where you need a building approval
- A structure that bears roof or floor loads
- A boundary wall or retaining wall above a certain height (varies by council)
- Any plumbing, electrical, or drainage work inside the structure
In Queensland, any structural work on a Class 1a building needs an engineer and a licensed builder. Papercrete furniture, garden beds, and non-structural shed walls don't. If you're unsure, ring your building certifier before you start.
FAQ
Is papercrete stronger than concrete?
No. Papercrete is a lightweight composite. Concrete is far stronger in compression and is the right choice for anything load-bearing.
Can I use papercrete for a house?
Not as a primary structural material in Australia without engineering certification and likely not at all for code-compliant housing. It is suitable for non-structural panels, sheds, and similar.
Does papercrete insulate well?
It provides some thermal insulation because air is trapped in the paper fibre pulp matrix. There is no universal published R-value, so don't design your wall assembly around a number you can't verify.
Will papercrete rot?
The paper component will rot if it stays wet. A render, damp-proof membrane, and roof overhang prevent this.
Can I use any paper?
No. Avoid glossy or coated paper because it resists water absorption and won't bond into the matrix. Stick to newsprint, plain office paper, and uncoated cardboard.
How long does it take to cure?
Papercrete is typically cured for 24–48 hours before demoulding, with full strength reached within about two weeks. Keep it damp during this period.
Sources
- https://successformulalab.com/how-to-make-papercrete/
- https://everydayselfsufficiency.com/how-to-make-papercrete-the-ultimate-building-material-for-off-grid-living/