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Entries in hoop house (4)

Thursday
Jan162014

Get them greenhouse rodents

Someone asked how we deal with seasonal rodents in the greenhouse and the answer is a pretty simple system actually. It's nothing more than a cheap mousetrap, a big nail and a section of old drain pipe.
Simply find the runways where the voles, moles and /or mice travel. Place a big nail through a hole drilled in a mouse trap and press the trap into the middle of their highway. Load the trap and don't worry about any bait. Then place a section of cut pipe or old gutter over the runway and trap so it looks like a dark tunnel. That's it. Check your traps twice a day and before you know it - there won't be anything left to trap!

Tuesday
May032011

Building a High Tunnel Hoop House / Green House : Part 3

Plastic Plastic cover ready!

We finally had enough of a break in the wind and weather around here to do the last of the work on the hoop house / high tunnel.  That "last of the work" would be to install the plastic.  A quick search of the web on how to install greenhouse plastic didn't really offer a lot of suggestions or help.  Further more we knew we were going to be inflating the two layers of plastic with a greenhouse inflation blower...  and that too isn't well documented out there.  So - here's the tools, techniques and lessons we learned in the last phase of constructing this greenhouse.

Wiggle wire Wiggle wire

First, we decided that the easiest way to attach the plastic was using a wiggle wire system like most commercial greenhouses.  The wiggle wire is a bent piece of stainless steel wire that fits inside a specially designed aluminum channel - the wire presses and pulls on the plastic and the channel follows the contour of the greenhouse.  The idea is to basically close the plastic over the structure on 4 sides kinda like a big 4 sided Ziplock bag then pump air into the space between the plastic to create a layer of insulation and keep the plastic taunt so the wind can't grab a hold of it and rip it off.  Pretty simple system that goes together pretty fast.  time will tell how it handles the winds we get up here!

How do you get plastic on a greenhouse?


Pull and hold The long side

That question was one we couldn't get a really good answer on.  We waited for a calm day (no wind) and then pulled the plastic layers over the hoops.  The inner layer is a infrared reflective layer to keep the heat in at night and the outer layer is typical greenhouse plastic.  Once it's draped over the structure we picked a corner and started working from there.  The general approach is to close things up like a plastic bag...  starting at one side and working our way around.  By doing things like that the plastic can shift and slide as we pull on it and we can minimize wrinkles in the final layout.  So, we started on one of the longest sides by installing the wiggle wire the entire length.

From there we then went up along the end hoop.  The only place s the plastic is attached is on the long bottoms and then along the contour of the end hoop (again - so the entire greenhouse can be inflated).  The process works best with at least 2 people, we could have easily used a third.  One person pulls on the plastic to ensure it's tight and the other person installs the wiggle wire.  (Kelli will tell you the worst job is the hand cramps you get for pulling so hard on something as slippery as plastic - I might tell you the worst job is mashing your fingertips over and over with the wiggle wire in the channels...  honestly, neither job is horrible - but also not something you look forward to repeating!)

Installing inflator Inflator - go!

With the plastic secured along almost the entire greenhouse, we left the corner where the inflator gets installed un attached just enough so I could worm my way in-between the 2 layers of plastic and cut a hole through the inner layer.  In this picture you can see the white dot looking thing - that's the diffuser that the inflator motor blows through.  It sites between the 2 layers of plastic and keeps the space pressurized.  One thing I decided to do as an added precaution was to place a piece of 4" wide greenhouse tape over the spot where I cut the hole.  That should help keep this area for developing any stress tears over time as the wind punishes the structure.

Inflated Yup - it's inflated.

After the inflator fan was installed we finished installing the last of the wiggle wire in that corner and trimmed off the excess plastic.  We then fired up the fan and let the greenhouse puff up.  It was an impressive site to see as the wrinkles all disappeared and the plastic shell became a component of the structural support for the building.  Very impressive design.  We have noticed that our blower seems to be a little "over active" and we have ordered a control switch to dial in the perfect amount of "inflation".

All in all without a final tally of the receipts the project came in a little more than we thought it would (don't they all) BUT the structure is a LOT more substantial than we expected and are pretty optimistic that it will sustain the big winds we get.  Total price tag including all the mistakes and the bender we will have for years : around $1500.  So given it's size, that's like $4.46 a square foot of protected, sun warmed space (not to bad) We also learned a TON in doing this, knowledge that would have been REALLY expensive to acquire on a full fledged kit.  Actually - after we finished it we both looked at the space next to it where the bales of hay sit and discussed how long the next one will be.  :)  The last thing we have left to do is attach the last little rolled up plastic that is along the hooped ends to the faces.  It's a small job (just not done).

We also learned several things we would differently next time.  Big doors on both ends.  Translucent panels on the ends.  Grade the area where it will be constructed first (building this OVER the low tunnel was stupid and caused things to be much more difficult than they needed to be).  Install water hydrant inside the house for easy water access.  I'm sure there will be other lessons learned too - but in the end - we are REALLY, REALLY happy with our homemade greenhouse! (for a few more pictures visit our Flickr Photostream)

The plants that have been moved inside the new greenhouse seem to like it - but they are not very vocal anyhow...  Stay tuned for a tour of the inside...

Done Our first homemade greenhouse

 
Sunday
Apr102011

Building a High Tunnel Hoop House / Green House : Part 2

Just to set the record straight before we get into this... The last post on Pigs Milk Cheese was an April Fools post (nice job to those who caught the date). Also - if you haven't ordered your pastured chicken yet - you should.

Baseboard framedWith the posts in the ground (from the first post) there's still a fair amount of work to be done, we needed to get a wooden base around to frame up an attachment point for the double layer of plastic.  We also need to get the hoops installed, the spine installed and then some nifty wind bracing installed so we have a prayer of sustaining those 60 MPH+ winds we get on the hill here without watching our hard work blow into the next county.  So we started with the base boards.  normally people install larger treated 2x something boards - but looking at the price of lumber we decided to go with a much less expensive treated 5/4x6 non-premium decking board.  In reality, these base boards don't offer much more that a place to attach the plastic so there's no need to them to be super heavy duty.  They are attached by drilling a hole through the board and the post and then attaching with a 1/4" stainless bolt and nut.

Leveling the baseboard

The challenge of installing the the base boards is really all about level ground.  The posts were driven in to an approximation of "level" - but adding the base boards required a fair amount of finagling.  All said and done, the lower end of the structure has the baseboard about 4" above the soil and te high end has the boards about 3" into the soil.  And we picked one of the more level areas to site the greenhouse!



Green house end wall

With 3 sides of the base completed (we left the end with the door open as it cuts through the existing low tunnel AND we are still debating about making the end door tractor friendly as well) it was time to start to assemble the superstructure, and all that starts with an end.  So, we used the backhoe to dig a couple of 3' deep holes and dropped some old treated 2x4's in.  Those were then lined up with the end hoop, cut to length, notched and bolted to the hoop itself.  The spacing for the end posts we determined by the 2 tripple track storm windows that came off the barn when we resided it.  They are big and will provide LOTS of ventilation on the west end of the green house.

Installing the hoop house spine

Once that "wall" was built, the process really takes off.  It becomes an exercise in joining the 2 halves of the hoops we bent with stainless self tapping metal screws, then inserting them into the posts that are attached to the base boards.  After all the hoops are up, the next step was to use some special (and expensive) clamps designed to attach the spine down the top ridge line.  This addition locks all the hoops into a single structure and really provides a massive amount of rigidity to the structure.  Up until this point we kinda felt like we were kids making a sandcastle at low tide...  just waiting for the wind to pick up and blow out wiggly metal structure into 100 little pieces.  But with each rib being attached to the spine (yes, I loved Moby Dick), the whale of a structure became more and more solid.

After the last section of the spine was installed and cut to length all we had left todo was install a set of diagonal wind braces and the windows.  All in all, the steps in this part of the installation only took about 5 hours over 2 days and were the most rewarding steps.  We can now stand back and look at something that resembles a green house.  And the most rewarding part has been the discovery of how strong this structure really is.  The spine and the wind bracing has made the and wall solid and we really think this structure is going to be able to take the winds.  As a matter of fact we are already thinking of LOTS of ways we can expand this design for something like a roaming pasture warmer for the chickens in the middle of winter...  At any rate, tonight we place the order for the plastic, inflator fan and various other parts.  Time marches on and our seedlings in the basement are getting ready for a nice warm "real sunlight" house!







Hoop houseFLoating Windows

For a few more pictures of the process - visit our Flickr Photostream to check things out.
Monday
Mar212011

Building a High Tunnel Hoop House / Green House : Part 1

Quite a while back we asked for input on Facebook from everyone to see what YOU would do if you were out here on the farm...  the question was - would you buy a JD Gator or would you buy a greenhouse?  The results were split 50/50 so we knew we needed to make both happen.  As you know - the Gator transaction was completed a while back...  As for the green house / hoop house...  well, construction started this weekend. The process is actually very straightforward and we are moving through the steps at a pretty rapid pace.  Basically we bend all the tubing we need for the hoops, we pound some slightly larger diameter tubes about 4 feet into the ground, screw the arches together and slip the arches into the tubes.  We start with standard line posts for a chain link fence and cut them into 4' lengths with a metal cutting blade on the 12" chop saw.


 


Starting to install a green house / high tunnel


The tools for pounding the tubes into the ground are pretty simple and with the ground being so wet right now the process is actually pretty easy.  First we marked off the house with string in a 12' x 28' rectangle.  Then using a mallet the post gets pounded about 6" into the ground.  The level and the big post driver help get it father down and straight too.  The last 6" takes a sledge hammer...  that tends to round over the top of the pipe in the ground but as long as the 1 3/8" pipes for the hoops fit we are OK.  If the opening gets too small, we use a bar to pry open the rolled metal.  Very simple process actually.

 

Bending the galvanized tubes for the high tunnel


To bend the tubes we mounted a 3/4" sheet of plywood on the back of our Gator and then mounted the tubing bender to that.  Then it's a little elbow grease and a lot of back pulling to make the straight tubes that were bought at Home Depot for chin link fencing into the curved halves of the hoop structure.  Once we got the mechanics worked out I can feed and bend and Kelli can pull and keep the tube flat.  It takes about 30 seconds to bend half a hoop.


Kelli removing a bent hoopA stack of bent tubes


After bending the tubes Kelli removes them from the opposite end of the device and then stacks them in the barn.  The ends are painted to match the corresponding other half of the arch so when they go out to the field we know which ones go together.  To build this particular structure we need 28' of support which is one arch every 4'...  so that's 7 arches, plus one for the end...  and 2 bars per arch...  calculator says...  16 total tubes bent.


The high tunnel takes form


The last step is the most rewarding...  inserting the ends of the arches into the tube in the ground.  The arch (or hoop - that's why they call these a hoophouse) measures about 14' wide when it's not flexed so we "squeeze it" down to 12' to make the hoop house structure.    The insertion of these hoops under tension adds a great deal of strength to the finished structure.

As it sits now you can see we installed a single hoop mainly to feel good about our efforts...  but to the left of the picture you see a whole bunch of pipes laying in the weeds waiting to be driven into the ground so we can attach more hoops.  We still need to build the base around the hoops out of some pressure treated 2x8 lumber, install a support along the spine of the structure, build some ends and then finally install the plastic...  that's ALL. :)