The topic of bale decomposition and pest control (particularly rodents) has come up several times in the last few years across my desk. It is one of the reasons I do not overly recommend SB (straw bale) architecture to many folks these days. Some SB builders (even with experience) will too often downplay this issue that is anything but small. I have seen Carpenter Ants hollow out window sills (they don't eat straw...they live in it) and this fact alone make "detailing" SB buildings a big concern and focal point of any "good SB design."
Now I am not saying that it can't be done...it can. Nevertheless, the bales at any location of bearing (ground, sill plate, rafter plate etc) and any bales that have penetration for fenestration or other types of openings must all be fully encapsulated at all times in a none penetrated clay and/or lime render. I personally will not design any SB structures that:
1. No load bearing or structural SB...I will only facilitate non-structural forms that have a timber frame superstructure.
2. All SB that are in locations of penetration or bearing are encapsulated in both galvanised screening and 1/4" galvanized hardware cloth.
3. The render (plaster) in these locations is also more heavily fiber reinforced and the client is also well informed to always monitor these locations.
To validate a little for readers that haven't followed my writing, besides being a professional builder of traditional and natural architecture I have also been a state supervisor in both Wildlife and Pest Control. I have seen and had so many stories related to me over the decades by SB enthusiasts of issues they had particularly with rodents and burrowing insects. Flying squirrels, Chipmunks, Red Squirrels mice, rats, voles, etc, etc...and the list just goes on...are all very attracted to the dense packed bales, and houses in general. Almost all locations have some variety of Rodentia that love to make their homes in these structures. I would further note also that once an animal has developed "site tendency" for a location and its architecture the battle with them is never ending...
This is one of the primary reasons I recommend Slip Clay systems over SB...If there is budget for excellent detailing...then SB is excellent. Logistically and ergonomically I am not convince it is the easiest structures to facilitate...
DO NOT LET THEM MOVE IN!!
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