Greenhouses

[MarcR]

Last summer I bought 2 greenhouses: a 10 ft X 20 ft aluminum tube frame & fabric covered tunnel, and a 10 ft X 12 ft polycarbonate house.

In November 43 mph winds damaged both frames. The polycarbonate panels and the fabric cover survived My homeowners' insurance covered my financial loss.

I just built a frame for the tunnel using 1" PVC pipe & fittings. I reinforced the PVC pipe with aluminum flat-stock from the frame pf the plolycarbonate house. It is firmly anchored to the ground in 8 places. It is flexible enough that it will not break even if it collapses.
The frame is a 10 ft by 20 ft  rectangle with vertical members 4 ft on center. immediately next to the T for the vertical member on the top of the frame is a T for a rafter. At the midpoint of each end is a T with a 1 ft vertical member and an elbow. the center of the roof is cross Ts at 4 ft intervals. Connected to the lateral openings of the cross Ts are 2 elbows to which the rafters connect; thus forming a gambrel roof. Since the frame I built is taller than the original frame, I used panels from the polycarbonate house for skirting at the bottom.

I intend to replace the polycarbonate house with one rated for 60 mph winds.

I am using the polycarbonate panels to build cold frames and planter boxes.

[Graeme]

Marc - if you have the space you might want to consider putting a wind break in near the buildings - above where we have our tunnels I built a 4 foot high retaining wall to level the ground off and to the side that has most wind there are split bamboo fencing above a stone wall to about 9 feet.

This in effect takes the wind over the area where all the building are - in fact when it is really windy here the centre of the nursery is a 'dead' zone

Wind netting or slatted fencing will also produce the same effect - you just need something to break it up before it hits the buildings

The tunnels were also shaped to withstand higher levels of wind as we are quite high up and on a fairly exposed site

[MarcR]

Graeme,

Thank You

I was planning to use 4 Panels from the polycarbonate house to form a wedge on the south side of the tunnel. Our prevailing winds are from the West; but they are gentle. Gale force winds come from the South.  The tunnel will be between the wedge and the new polycarbonate house.