What are eco-friendly substitutes of wood?

Question

Are there any eco-friendly substitutes of wood?

With similar attributes (such as strength, rate of biodegradability, safe for the environment, etc.).

My long-term intend is to save our environment from pollution (e.g. by using plastic) and the Rainforest devastation (including wildlife) by using alternatives eco-friendly substitutes of wood.

Answer 1

Wood is close to the most eco-friendly building material around:

• It's renewable.
• It's production overall pulls carbon out of the atmosphere.
• Material tied up in construction is carbon that isn't in the atmosphere.
• A lower fraction of its cost is transport since the building grade wood is sourced locally when possible.

The issues people have with the growth and harvest of wood:

• Logging is ugly.
• Done badly on steep slopes it causes erosion.
• It's disruptive to the local wildlife.

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But let's take your question at face value: To be be more eco-friendly than wood, it requires the following attributes:

• Even more local than your neighbourhood forest.
• Renewable, or be from a very large resource not currently in signficant demand.
• Low in energy to gather, process and use.

Wall Construction

Option 1. Dirt.

You are digging a hole for the basement anyway. Use that dirt to make adobe, or cinva-ram blocks, or cob. These materials give you high thermal mass, which in hot dry climates averages out the high daytime and low night time temperature swings. All of these have to be protected from rain. See option 2.

Option 2. Strawbale.

Pioneered in Nebraska shortly after the first horse drawn balers appeared, the oldest strawbale buildings are over a century old. Currently big in the alternative construction crowd, it is the easiest and best (IMHO) construction method for small buildings in dry climates. In much of North America building material is within 50 miles. Walls are coated with lime, earth, or cement based plasters on inside and outside walls. Google 'strawbale construction' for details.

Option 3. Leichtlehm.

This is a sensible infill system for post and beam construction, so it doesn't eliminate wood, but reduces both the amount, and the processing required. Leichtlehm uses straw dampened with a clay slip, and packed into forms made between the posts. Traditionally a small amount of barley is added when filling the forms. The process is fairly rapid. The forms can be moved to the next bay immediately. One level a day is easily done.

The barley sprouts, drawing water out of the straw. Eventually the barley dies, but its mat of roots helps hold the straw together. The wall is finished with lime plaster.

Option 4 Stone

Go look at Scotland, especially the highlands. These people take a nuisance (stones in field) and turn it into a resource.

Stone construction is slow, requires mortar (high embodied energy) but the buildings last. Stone is also a bad insulator. Even a 2 foot wall does little more than average a chill day with a cold night. Most stone buildings have an interior wood lining which uses nearly as much wood as a conventional stick built house.

Floor construction

While we pride ourselves on no longer living with dirt floors, a earth based floor can be quite workable.

Option 1. Clay on grade.

Mix up using typical adobe mixes. Mix as dry as possible, and pack HARD into place. Screed, and fill to get a flat surface. Allow to dry. This can take a couple of months. Oil with boiled linseed oil. Repeat, allowing each coat to polymerize before adding the next coat.

In some cases the floor has cracked -- too much clay in the mix. Apply a contrasting colour of clay mix as a liquid slurry and wipe. The net effect will be of an incredibly even job of laying grouted flagstone.

Option 2. Clay on on insulated slab.

The above doesn't work well in cold climates. The floor stays too cold. Lay down 2-6" of closed cell foamboard first, followed by 4" of crushed stone "road

Answer 2

Coconut tree and Bamboo are two alternatives of timber i can think of, if you want wood's characteristics you mentioned.

• strength
  acceptable

• rate of biodegradability
  you'll worry about how to preserve it instead

• safe for the environment
  just chop em up and burn (as fuel)

However it only work if the source is near your place (plant them yourself or with your neighborhood), and it can live in your environment.

Bamboo

http://en.wikipedia.org/wiki/Bamboo

Advantages over wood:

1. Bamboo is fastest growing plant, it was so fast that cutting some to make a small all-bamboo building just like weeding your lawn.

   Certain species of bamboo can grow 35 inches within a 24-hour period, at a rate of 0.00003 km/h (0.00002 mph)

2. It spreads its root, so you can get even more bamboo without replanting it.

3. More elastic than wood, and hollow, so you can make pipe out of it (or water container). Just search "bamboo structure" and be amazed
4. Bamboo shoots are yummy
5. Can be used for lots of stuff starting from basket to wall. It's easier to process than wood, you just need a machete and knife to make it into ANYTHING, except composite bamboo.
6. Costs less energy in processing.

Disadvantages:

1. weaker in supporting weight. However can resolved by adding the quantity or use coconut tree's wood instead for support
2. small in size, so you need to do workaround to make flat structure, like making "gedeg" (javanese).

Coconut Tree

http://en.wikipedia.org/wiki/Coconut

Advantages over wood:

1. Relatively fast-growing, easy to plant.
2. You can use every inch of the tree, literally
3. You can get other resources while waiting it to grow, like coconut, leaves, young leaves, palm sugar, etc. (ask me later if you interested in this section)
4. strength wise, it's getting more strong overtime.

Disadvantages:

1. Very heavy, harder to process than bamboo, or small-caliber woods
2. Bad processing may hurt you, since its needle like part of the log can pierce and stuck beneath your outer skin (trust me hurts).

Actually both material are more widely used in my country (at least my ethnicity - javanese) since it's a lot cheaper than using wood, and have a lot of alternative use rather than just as building material. Sorry if there's some unclear stuff because i can't easily explain some part that i don't know the English word of it.

Answer 3

A good sustainable substitute for wood is Clay and Stone as they are renewable and stronger than wood. Although it is costy, it is worth it

Answer 4

Well, steel that is recycled in arc-furnaces produces less air-pollution than iron-ore processed in blast-furnaces.

One way to increase the recycling of steel would be to use stainless-steel which would be more valuable in recycling.

Now 304L and 316L are available in standard structural shapes and are designed for simple arc-welding. Then 304L and 316L are available in hot-rolled, cold-rolled, and brushed. Now 316L is expensive while 304L is moderately expensive. But a small shop might find 304L at wholesale cost to be competitive with common steel at retail cost.

But there is some good news here in that 409 and 430 are about 50% less cost than 304L. Then 409 is often alloyed for welding while 430 is more likely to be bolted. However, 409 and 430 are not available in structural shapes but are folded to shapes from sheet metal.

Of course entire houses are framed with light-gauge-steel which is folded-steel and so consider 409 for this application. And stand-alone joist-shapes are available in light-gauge galvanized-steel and so consider 409 for this.

Now 304L can be used out in the weather while 316L might be attempted near salt-water but not in salt-water. Then 409 can be used near the weather while 430 can be used out in the weather. Basically, 409 will not rust in the house crawl-space.

Furthermore, 430 makes good roofing because it has about the same thermal expansion as common steel. But 430 shouldn't be cut with a cut-off disk but should be cut or drilled with machine tools. And 430 shouldn't be bent back-and-forth but bent one time to shape.

Stainless-steel was suggested because it is more valuable in recycling and because it will never rust away. However, structural pieces of stainless-steel could also be re-used and that is much more valuable than recycling.

Now consider the use of rebar in concrete. The rebar in concrete will be rusting if the concrete is out in the weather. Then after the rebar rusts away the concrete will begin cracking. Now 430 is the minimum choice for rebar because concrete soaks up water but 304L would be better for rebar.

Aluminum, in general, is not suggested because aluminum corrodes when out in the weather. Also, aluminum is not good for taking a flexing load because of cracking. And aluminum has a large amount of thermal expansion when used for roofing.

Actually, my most likely house build will be 304L joist-holders on 304L tubes and set in concrete footings. Then lumber joists and studs will sit on the joist-holders bolt to the side of them. In fact use two studs at each stud location and then a ceiling joist can sit on one stud and bolt to the side of the other stud. The 304L jost-holders are simply built with a metal-cutting bandsaw and an arc-welder. But in this application, I'm not forgetting about lumber.

Answer 5

I'd say your premise is flawed, i.e. wood is pretty much the most ecological building material available because 1 solid cubic meter of wood sequesters approximately 1 tonne of carbon dioxide from the atmosphere (compare that to concrete, the production of which releases carbon dioxide).

However, do select the species of wood carefully; don't use a species of wood that can be only obtained from tropical rainforests.

If highest density and hardness is not your criterion, my recommendation would be to obtain some pine or spruce from sustainably managed boreal taiga forests. The cost is not high (less than 100 USD per cubic meter of sawlog, although sawmill product costs easily 200-300 USD per cubic meter, as the sawmill labor and investment costs have to be paid and a sawmill is unable to utilize all of the sawlog).

If you want hard, long-lasting and durable wood for making tables or other similar furniture subjected to hard use, I suggest oak. My understanding is that most of it is produced in a sustainable manner.

Edit: I was reminded of the importance of using wood sourced locally near the area where you live. So, let's analyze how important it is to source wood locally.

20-foot container shipping around the world costs perhaps 1000 USD (juts google for "20 foot container shipping cost") and can store 39 m3 of wood, meaning shipping is 26 USD / m3 of wood. Sawmill products cost ten times that even in areas where forests are plentiful.

According to https://www.freightos.com/freight-resources/ocean-freight-explained/ shipping 2 tonnes (4 cubic meters of wood) for 5000 km will emit 150 kg of CO2. This is 37.5 kg / cubic meter of emitted carbon dioxide. A cubic meter sequesters 1000 kg of carbon dioxide, so only 3.75% of the sequestered carbon dioxide is emitted in shipping.

Based on these figures, we can conclude that:

1. Shipping adds 10% to the cost of sawmill products
2. Shipping emits 3.75% of the sequestered carbon dioxide

If you want to be ecological, you should therefore first select forests that are as sustainably managed as possible and only secondly select forests that are near the area where you live. It's more important to be sustainable than to ship locally.