[GSBN] earthen floors (resilience)
bob at bobtheis.net
Mon Jan 9 19:53:07 CST 2012
In the end, as places for humanoids, floors are an expression of human sensibility.
Dancers will perform on packed earth without blinking. Ask them to perform on a concrete slab. Go ahead, just ask some. Throw in some psi figures for good measure; their legs know better.
And these are people who will break their piggy banks to put a good floor in a loft space they can't afford to heat, so their insistance is not about the pleasures of padding around on warm floors.
Numbers will only take you so far. From there, it's touchy-feely.
On Jan 9, 2012, at 4:50 PM, RT wrote:
> In Fri Jan 6 GSBN Digest
> Bob Theis wrote:
>> we like the stuff beneath our feet to be resilient. Concrete is not.Earth floors are that
> [snipped for brevity, see GSBN archives for full text of message and
> ensuing thread
> http://sustainablesources.com/pipermail/gsbn/2012q1/001861.html ]
> I know that a fired clay brick will demonstrate measurable deflection
> under load with sufficiently good instrumentation in a lab but if someone
> were to smack me in the back of the head with that same clay brick, the
> amount of deformation that brick undergoes would do little to alleviate the
> pain that my head would feel after being smacked.
> Similarly, I do wonder if earthen floors are actually as "resilient" as Bob and others espouse.
> (Not that I don't believe that they believe them to be so.)
> Why ? Well, lemmee tell ya.
> I have vague memories of Beel having sent me a sample of an earthen
> mix years ago (I forget whether it was straw/clay/sand or
> sawdust/clay/sand) and out of curiousity i sawed off a 1" x 1" x # inch
> chunk, took it outside and started piling concrete block and bricks onto
> it to get an idea of the approximate compression resistance of the sample.
> I don't recall the exact weight (somewhere between 75 and 90 lbs if I
> recall correctly) under which the sample started to show signs of failure
> but I do remember that its bearing capacity struck me as being impressive.
> (I think that I may have sent in a message to the SB-r-Us List on the
> matter back then).
> Nor do I recall whether the earthen mix was intended for use as a wall
> plaster or a flooring material but I think that it would be reasonable to
> assume that even if it were a wall plaster mix, the compression resistance
> of the sample (ie somewhere between 75 - 90 psi) would at least be equal
> to that of one of the Mud Masters' (ie Athena and Beel) earthen floors.
> I also think that it's reasonable to assume that the substrate under the
> densely-compacted finished surface (ie the drainage layer and "structural"
> sub-layers) would be compacted to a density whose compression
> resistance would be at least 30 psi.
> At those compression resistances, like the
> being-smacked-in-the-backside-of-the-head-with-a-brick scenario mentioned
> at the outset, I wonder if the oft-mentioned resilience (ie elastic
> deformation) of an earthen floor mix, when subjected to the load of a
> standing humanid or canid or felid would be of sufficient magnitude to
> provide any actual physiological benefit ? (Not that I'm discounting the
> the value of any psychological placebo effect).
> If the earthen floor surface were so resilient as to deform elastically to an appreciable degree under the load imparted by an unshod human foot (ie stress = ~60 -80 kPa (6-9 psi)) then I would think that First Worlder earthen floors (which clients typically want to have a high-ish degree of serviceability) be would show yearsworth of shoe and paw imprints(since dogs & cats can't remove their claws at the door) and permanent indentations from heavy furniture and quite possibly (bare) foot imprints too, not that those are Bad Things. ie In the same spirit as the chrysanthemum-shaped patches on paper shoji "a thousand flowers blooming" where little jamfaces are about)
> Me ? All of the floors in my home are either stone, porcelain or wood and I am usually barefoot when walking on them and I would say, that for the most part, a smile(or a smirk) will be found on my face. (re: Graeme North's comment about smiling faces being exclusive to earthen floors)
> I would venture that an argument could be made that the barefoot tactile delight one experiences has more to do with having removed one's shoes or perhaps the floor temperature (ie cool during the hot months, warm during the cold months) than it does a particular floor material.
> But you won't catch me trying to make that argument here. Nosirreebob.
> === * ===
> Rob Tom
> Kanata, Ontario, Canada
> < A r c h i L o g i c at Y a h o o dot c a >
> (manually winnow the chaff from my edress if you hit "reply")
> GSBN mailing list
> GSBN at sustainablesources.com
More information about the GSBN