[Homestead] Re: Polycarbonate

Bill Jones billj at harborside.com
Sun Oct 3 13:43:56 EDT 2004


Gene wrote:

>Sun porches and greenhouses are of high homestead importance. Please tell 
>us the characteristics of polycarbonate, why you chose it, what 
>alternatives you considered. Are you doing a single or double wall? What 
>are your vent plans for handling overheating? Will the sun porch be used 
>for winter food production? What are your plans for backup heat?
>
It's Suntuf brand, in a single layer with ribs every 4 inches.  Last 
year I decided to replace part of the porch roof with something that 
would let in light.  The people who built this place must have been from 
Medford, since it has a deep, dark porch and tall conifers planted on 
the sunny side of the house, as if we were preparing for temperatures 
over 100F every day.  Not!  After a year with half a clear porch roof, 
I've decided we could live with even more light.  So I'm doing the 
remainder as well, if someone could ever get over here to do a roof...

Since it looks so nice and clear, I decided to have a completely 
enclosed sun porch.  That I'm able to do all by myself.  I never thought 
about Plexiglas or fibreglass much, because they're heavier and cloud 
up.  It's also nice that I can nail right through it.

I think we'll eventually do a double wall.  The first layer is going on 
the inside of the 4x4 uprights; the second layer will go on the outside 
(I have to cut several shims/spacers to do the outer layer).  They have 
double-wall (and even triple) poly, but it's expensive and thick 
(because of the air space).  I'm happier to be able to add a second 
layer when I get around to it.

There's one door where we go out the front, and a door on each end.  I 
think this is enough ventilation, with 3 doors opening off a 200 sq. ft. 
sun porch, but I guess we could cut a window as a last resort.

We grow so many vegetables outdoors in winter in our mild climate, and 
it's not really vital.  At this latitude there are limits to what a 
tomato seedling can do in the winter, even if it's always warm, but 
older potted tomatoes would go on bearing fruit all winter if they just 
got an early enough start.  At this point I still don't even have a good 
south window to raise pepper seedlings in the spring, since the deep 
dark porch covers the entire southern exposure of the house.  We also 
raise an unusual edible tuber called ulluco.  Ulluco is an easy to grow 
vine, but it's photoperiod sensitive, and it makes tubers from runners 
that form in autumn (after the daylength goes below 12 hours).  The 
runners must be buried, and will make tubers much like a peanut makes 
nuts.  But they're never early, of course, and the vine is 
frost-sensitive.  This year I'm potting up the runners on the sun porch, 
and leaving the pots on some trays I just acquired.  Down in the 
greenhouse the whole set-up requires a rat-proof cage, because ulluco is 
high in calories and very popular.  I'm sure I'll come up with some 
other great plans.  Maybe I'll keep a sweet orange tomatillo (Physalis 
peruviana) in a pot; after a few years they get huge with hundreds of 
pineapple-flavored fruits that keep all the way through winter.  Maybe a 
ginger in a terrarium?  The best possibility for voiding homeowners 
insurance might be a Physalis rooted in the dirt under the porch, one 
that passes through a small hole in the floor and trails over a trellis 
inside the sunporch.

The main purpose of the whole thing is to stop losing the heat that goes 
out our front door in winter.  There's an inch-wide gap under the front 
door!  I'm used to camping out so we've lived with it that way for 
years.  Most of the time it's warm enough not to matter, and when it's 
really cold the wood stove heats it up so hot in here that you'd be glad 
for that gap.  Opening the door will allow heat to fill the sunporch.  
Anyway, until I get the second layer on, a little space heater might be 
necessary for the guinea pigs on freezing nights.  They have a plastic 
cage cover that keeps their environment warmer than the surrounding 
air.  Plants generally only need to kept from freezing.

Bill
S. Oregon coast








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