## Wednesday, May 16, 2012

### Of 4H Economics and Yurt Rings

Tomorrow Sophia and Grace turn in their 4H "Record Books" which document their 4H work over the course of the year.  For their animals, one of the things they were asked to do was calculate:
(income or value gained) - (expense) = (total income or loss).

Here are their calculations:

Goats
Expenses
-\$270 for 9 months food  (about \$30/mo--1 hay, 1 ration)
Income/Value
+\$288 milk (about 2 gal/wk for 6 months @ \$5 gal)
Net
+\$368

Chickens and Ducks
Expenses
-\$60 for 9 months duck food (2 bags every 3 months @ \$15 ea)
-\$4 for purchase of ducks
-\$144 for chicken food and purchase (1 bag/month @ \$15 ea)
Income/Value
+\$180 duck eggs (approx. 1 doz/wk for 9 months @ \$5/doz--that's 432 eggs)
+\$15 for sale of ducks
+\$360 in chicken eggs (approx. 2 doz/wk for 9 months @ \$5/doz--that's 765 eggs)
Net
+\$347

Good work, girls!

In other news, Eli and I went fishing early this morning.  We were hoping to catch a fish, dissect it, cook it, and eat it.  We didn't catch anything, but it was still pretty fun.

Also, we got the yurt stained this week.

Speaking of our round dwelling, I've been working on an issue that probably interests no more than one reader of this blog, and he already knows about it.  Nevertheless, it has been taking a significant amount of my mental and physical attention the past few days, so I will describe it briefly:

The yurt has a strong 5' diameter wooden "compression" ring in the center of the ceiling.  This is what all the roof rafters--that start at the top of the walls--connect to.  Above the compression ring is another 5' ring made of metal.  All of the external metal roofing panels bolt at their tops to the outside of this metal ring.

The other day, while on a ladder inside these rings at the ceiling, I noticed a 3/8" separation between the rings.  Would you like to see a gap open up in your ceiling?  I didn't.  It was surprising and concerning as the rings are supposed to be bolted together and sealed.   Something had created a significant enough shift to snap all of the flanges that bolted the metal ring to the compression ring!  What could be causing this?  Maybe you would like to venture a guess?
Pictured: wood ring at bottom, metal ring above (painted tan).  You can see where the flange holding the bolt has snapped.  The dark brown caulking used to be attached to the wood, but you can see the separation that has formed.

I think I have an explanation and I am working on a fix with the yurt designers.  Let me know if you'd like to hear more as the saga continues!  (Spoiler alert/hint: everything should be ok and can be explained by basic physics).

Joey

#### 1 comment:

1. Answer: Drying rafters may play a role. They may have shrunk up to about .1% which could lower the wooden ring up to 3/8". But it has become clear that the main issue is expansion of the metal roof. Metal expands in heat significantly more than wood. So what is happening is the roof panels get bigger on hot days and lift the metal ring (they are bolted to it) up. I documented this on my ring over the day recently. In the cool morning: little or no gap; mid day (about 75 degrees): 1/4" gap, evening (cooling off): 1/8" gap. The big gaps I was seeing a week or so ago were on really hot days in the 90's or so.