Construction Materials TA

Investigations of various building techniques

Walls

I will try a few techniques on site. Resources will determine the best approach

Compressed Earth

Several variants. All provide high thermal mass but poor insulation.

Brick

Great material, but requires a press. There's a trade off that a manual press is more work, but cheaper and easier to setup.

I do think there's a good middle ground. A manual press with a hopper and sliding loader can go pretty fast. I could setup a simple wagon next to it at the same height with sliding slats so that as each brick comes off the press it can be slid onto the wagon, no lifting. When the wagon is fully loaded, drag it over to the drying area and stack the bricks.

Presses (all about the same, just different names)

• YLF1 40
• QMR2-40

I think I could do 2 bricks every 30 seconds with this. A wall 40' x 10' would take about 200 bricks (they are 900mm x 200mm). So about 75 minutes if I could work non-stop. With a team of 3 people, this would be feasible.

Walls

Labor intensive and requires forms. Final product looks very cool though.

Clay Fired Brick

Very traditional, but not too hard to make. I'm not sure what the right bonding material is. Traditionally it's straw, but I think that would burn when fired.

I think I could set up pre-processing to reduce the amount of sand in the bricks.

1. Wet mixture to flowing consistency and mix thoroughly
2. Pass through screen to remove stones and twigs
3. Let it sit for a few minutes (experiment to determine correct length) then separate manually. This should significantly increase the clay content.
4. Concentrate the clay successivly regularly pouring off spent water
5. Use solar heating and a mixer to bring down the moisture content to a workable level

I may do even better with just a very large filter. Get some cheap sheets, add nylon webbing for support and build a large wood frame.

The off cast dirt will be great for gardening.

I like the idea of a machine I can load up with clay and pedal and have it deposit bricks, though that may be a bit complicated. A simpler approach would be something that I could feed a board through and it would "print" the bricks on the board. When the board is full, set them aside to dry and feed in a new board.

Stone

Just requires that the site have enough stone to work with. Or I could buy stone (but I think that gets expensive fast). Depending on the stone, this may be a good option for the foundation.

Straw Bale

I was initially dismissive of this, but it may be a good fit. The straw provides a lot of insulation (which many of the other techniques do not) and a thick layer of plaster will provide the thermal mass.

Wood

If there is enough land, this may be an option. I do like the timber framing.

Corrugated Steel

Probably not for the main house, but for the workshop, or small sections of the house.

Framing

Studs

Not really interested, but this is most common.

Timber

Round or hewn, I have a preference for hewn.

Glulam

Glue laminate construction. I'm kind of drawn to this because it can form the bends that I like and I can work with less select lumber. But I also suspect it will be extremely labor intensive. Need to research how far a beam can bend at a given thickness.

Insulation

Common

I can get insulation panels, fiberglass rolls or blown insulation.

Mycelium

I'm fascinated by this. Use cardboard to grow mycelium panels. Have an R value of about 5 per inch.

Foundation

Slab

Probably not. It's easy and cheap, but hard to insulate.

Crawl Space

Possibly. I kind of like the idea of the floor either floating or being held down with simple bolts so that it would be easy to access the crawl space for storage.

Basement

This would be ideal, but it is unlikely I could construct this myself. However, there's nothing odd about this construction so I could hire it out.

Floor

Wood

Good for interiors.

Earth/Clay

Good for semi-exterior (shop, patio)

Thermal Mass

specific heat capacity in J/kg°C

• Water: 4200
• Cob: 890
• Masonry brick: 800
• Stone: 1000
• Timber: 1200