[quote=Susana Smith]Thanks James! That rules out wet wattles against cob in a wetter, cooler, less windy climate, as I suspected.
I have considered drying some claystraw in advance. I was thinking of blocks, but maybe wattles could work.
Have you ever done this?
Can you give an estimated weight for a dry 10' wattle? And would that be 12" diameter round?
Would a 10' length actually hold together for carrying and placement?
I may be able make some in advance in a nearby location, before my foundation and frame are done,
and given the long drying time necessary and the short building season, it seems worth considering.
Every week counts.
I am planning straight walls.
If some wattles were made and dried in advance, what would be the best way for me to combine them with others made and dried in-place,
given that I won't have desert sun and wind to dry the ones made in place? IE, they'd need to be open to the air on both sides.
Maybe layer it vertically?, some dry then some fresh etc.
Hmmm, maybe a core of pre-dried, with 2-3" of fresh wet claystraw on either side?
That thin it would dry okay if only open to air on one side? What do you think?
Have you got any idea what would be the optimum thickness of an outer crust sandwiching pre-dried wattles?
Thin enough to dry well but thick enough to glue the wall into a single unit.
Oooh, then the wall could exceed the traditional 12" limit, even up to the width of strawbales.
Wow, this might be a way to approach the insulative value of strawbale walls without risking mold.
Also, can you suggest sources for the bags?[/quote]
We have done some blocks recently and they're great, but haven't found an application yet. I surmise that it would be cheaper than framing up for a light straw clay application but I would do some tests first. For domes, it isn't as efficient I think. The containment of the bag is simply divine. It really allows for fluid application and creative curves and designs.
Estimated weight? Good question. I am reasonably strong and can lift a 14' wet length with no problem but I would estimate no heavier than 50lbs. It's awkward but contained in a bag but I would say it's like lifting a large worm. Ours was 8" around when stuffed but the bags stretch to varying sizes and the diamonds vary as well. 3/8" and 5/8" diamonds if I recall and the 9" wattles stretch to 17" so it really requires some awareness of how much you are filling the bag. The 10' lengths will hold, the bag is strong, but care is always a good rule of thumb. Try not to get the bag caught which may cause it to stretch. When dry simply be much more careful. Compacting the bag is necessary but not to the point where it's losing the R-value. What I mean by that is the air pockets created by the straw should not be compacted like tight bricks.
My suggestion would be to place some vertical 2x2's or even #4 rebar at 5' intervals and stack the wattles on top of each other like you are suggesting. Let's say 6 pieces of lumber or rebar vertically at apx 5' internals and spread about 9" apart. Like a vertical drying rack. That could work well. Given enough time they should dry according to the humidity in the air, sun exposure, etc.
Attaching them to verical walls will require anchor points in your wall, which we did with wooden dowels and zip ties. They aren't so heavy so it doesn't take much to attach them and plaster strengthens it all.
Overall I would allow the wattles to dry out first and then apply clay plaster just to be sure there is not mold. Spraying it all with a lime wash is a good way to abate mold ass well. Once you crust the wattle, it is tough to move too.
We sell the bags online, here is a link and if you would like to order some, email us :)
http://www.unitedearthbuilders.com/#!bag-supplies/c1o1j