Sometimes it happens that way. I'd love to see the finished project. That's a decent sized greenhouse.
Necessity Is The Mother of Invention
So I am helpng a friend build a Frankenstein greenhouse, using two HFT 10x12 greenhouse kits to make one 12x20 greenhouse. Of course we are running into issues when ends become sides, and sides become roofs, but it is coming together, fighting us every step of the way.
I chose to use the wall T-Slot ribs for the roof, and lower the pitch to accommodate the extra two feet of width. Unfortunately, I forgot about how the T-Slots butt up against the base, but they DON'T butt up against the end of the roof! So after the whole frame was built and we began to install the panels, that is when we noticed that the wall panels are 1" short! #$%$%&* So we had two options ... Take the roof apart one piece at a time, and cut the frame members 1" shorter to reassemble it, or find a way to make up that one inch of space.
I chose the latter option and bought some strips of the white plastic trim sold at the big box stores. But I needed some special cuts to make the extensions nest comfortably with the aluminum pieces, and the Lexan panels.
My solution was to buy a SKIL router table, and a HFT metal cart, and assemble them into a portable router. We only had 20 pieces to make. I tried a table saw first, but that was not going well. So I decided to add this router to my sop, and do the three cuts per piece that made them perfect for the situation. I already had the BOSCH 2.25 HP router, so I mounted it and Viola! The problem was solved!
This will come in handy for other quick jobs that do not require the CNC router table as well.
Joe
![Table Motor vehicle Gas Automotive exterior Bumper]()
I chose to use the wall T-Slot ribs for the roof, and lower the pitch to accommodate the extra two feet of width. Unfortunately, I forgot about how the T-Slots butt up against the base, but they DON'T butt up against the end of the roof! So after the whole frame was built and we began to install the panels, that is when we noticed that the wall panels are 1" short! #$%$%&* So we had two options ... Take the roof apart one piece at a time, and cut the frame members 1" shorter to reassemble it, or find a way to make up that one inch of space.
I chose the latter option and bought some strips of the white plastic trim sold at the big box stores. But I needed some special cuts to make the extensions nest comfortably with the aluminum pieces, and the Lexan panels.
My solution was to buy a SKIL router table, and a HFT metal cart, and assemble them into a portable router. We only had 20 pieces to make. I tried a table saw first, but that was not going well. So I decided to add this router to my sop, and do the three cuts per piece that made them perfect for the situation. I already had the BOSCH 2.25 HP router, so I mounted it and Viola! The problem was solved!
This will come in handy for other quick jobs that do not require the CNC router table as well.
Joe
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That is one huge greenhouse.....
The roof is together. We ran into the problem I was anticipating. The cheap aluminum frame is not rigid enough to create a rectangular door frame. This greenhouse has doors that roll on the edge of a C-shaped aluminum channel, and at the bottom, some unimaginably cheap and undersized plastic gliders are supposed to follow an L-shaped extrusion in parallel. The problem is that the doorway is hour-glass shaped, so the doors bind, and you have to fight them to move them.
I am going to re-engineer these door slides so they actually work. I want them to open and close like expensive mirrored wardrobe doors!
![Plant Sky Shade Tree Land lot]()
![Plant Sky Light Shade Fixture]()
I am going to re-engineer these door slides so they actually work. I want them to open and close like expensive mirrored wardrobe doors!
That is a LOT of mules!
Yeah ... I cannot imagine WHY HFT went so #$%%^& darned CHEAP on these completely worthless Chinese bolts they supply to assemble this thing. They are small 10mm bolts and nuts with thin and small square heads on the bolts that break off easily when you tighten them.
The square 10mm HEADS of the bolts slide into T-Slots in the aluminum extrusion, but the heads are too small to BIND inside of the T-slots! They can actually ROTATE inside of the T-slots! So when you try to tighten them by applying more force than a three year old child could produce, the bolt heads ROTATE inside of the T-slots, and the $%#$^& 10mm square heads cannot be held with another wrench!
If you use anything stronger than the completely USELESS 10mm wrench they supply which is about 45 mm long and stamped out of 16 gauge sheet metal, the bolts WILL FAIL. If you actually manage to tighten these nuts with a ratchet wrench or God Forbid ... a cordless impact wrench, the tiny square heads will pull right through the T-slots and render the ends of the soft aluminum extrusions useless.
When you build this thing, throw the supplied Chinese hardware away with violent decisiveness! Replace every single nut and bolt with a 1/4-20 x 1/2" or 1/4-20x3/4" bolt and a Nylok nut, with 1/4 steel washers. You can use regular 1/4" nuts and lock washer if you choose, but there are places where multiple layers of the aluminum frame will leave little threading for those thick lock washers.
The 7/16" (11mm) hex heads of these bolts fit tightly into the T-slots with barely enough room to slide them along the slots, and they WILL grab the T-slots as they are supposed to, and they will not rotate inside of the T-slots when you tighten the nuts. Be sure to put a 1/4" washer on EVERY BOLT, to prevent the real hardware from crushing the aluminum rectangular tubing of the cross braces and such.
All joints should not rely on the pinch of a single bolt at the end of the T-slot. Use the hanger strap to span the connection, and use TWO 1/4-20 bolts on each end of every joint (where possible), and connect them with a length of hanger strap that joins all four bolts together, with two bolts on either side of the joint. The second bolt will be further down into the T-Slot and will insure a TIGHT grip.
This strap will make the joint hold together as the wind pushes the frame of the greenhouse to and fro. You won't run into the issue of those small, poorly chosen inferior Chinese bolts slipping out of the end of the T-Slot as the joints are "worked" by the winds.
The basic frame of the greenhouse is ... okay. but I strongly suggest using additional aluminum or steel to reinforce the frame against wind forces that can turn a rectangle into a parallelogram. Diagonal braces at every corner, top and bottom, will make the frame a hundred times stronger. Where the braces cross under the T-Slots, add additional 1/4-20 x3/4" bolts to the intersections, and bolt them together, running the bolt and nut THROUGH both pieces.
One things that is good to know ... You can use a 1/2" drill bit to create a center entry point for the T-slots, if you want to add additional bolts into the T-slots AFTER the house is assembled. The 1/2" drill bit will open a small entry point where the 1/4-20 bolt head can be inserted into the T-slots from the middle, rather than just from the ends. The 1/2" diameter cut in the T-slot will not weaken the extrusion enough to worry about it.
Here are a few things we learned, too late to matter
. When you install the clear Lexan panels, Install them with the plastic protective film ON the panels, and remove the film only AFTER the panels are in place. We used silicone and adhesives for these panels to help insure that they will not be blown out of the frame via strong winds, but you know clear silicone from a caulking gun ... it gets EVERYWHERE! So our panels have some hand prints, finger prints and smudges where the silicone on our fingers and palms got onto the panel surfaces during installation, and it shows.DO NOT use acetone to remove the silicone from the Lexan. It will fog the plastic and make it look terrible, and in colder temperatures, the acetone will momentarily freeze the Lexan and make it brittle, causing it to vaporize beneath your fingers! The Lexan will become like rice paper! I haven't YET found anything that will cleanly remove the silicone from the Lexan panels.
Joe
The eyes are not like they used to be. I corrected it. We do live not far from the Borax mine where they once used 20 mule teams to haul the stuff across the desert. It's all rail cars now.That is a LOT of mules!
Sounds to me like you're not recommending this greenhouse. My wife keeps asking for one, but when it comes time to spend to money to have one built, she changes her mind. I wouldn't mind, really, because she keeps buying plants and bringing home flys and gnats, which eggs seem to live in potting soil from the nursery.
I have what looks to be the same green house but smaller, 8 x 16. I have 2 of them. I live on Vancouver Island and our property is high up and facing a valley so we get a fair bit of wind and often very strong winds. With the climate changing that scenario is likely to get worse. I didn't trust building that I could carry myself in a flat pack so I beefed it up, adding 2 x 2 steel stud strong backs and cross braces to the roof as well as wood 1 x 2's to the walls for wind as well as the occasional snow dump. I also tied the building down by bedding 4 x 4 posts in 10 x 12 concrete pads dug down 16" at each corner as well as the middle. These are lag screwed through the base plate from the outside. Four years, lots of wind storms and a couple of snow storms and they are still okay. When we get snow I clear off the roof fairly quickly as it usually doesn't stay cold very long and wet snow can get real heavy. Last winter we got around 20" in one dump.
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Wow! Your unit looks great! I started with the somewhat funky foundation made by the owner. I asked him to wait for me, but he went ahead and built a wood foundation without me being there to check on things. He is a great guy, age 79, and although he is willing, I didn't want this project to be the last thing he does.
I wanted to pour a concrete footing into a trench, and lay in 8x8x16" cinder blocks, straight, square and level into the wet concrete. Then top the blocks with a layer of the composite decking just above ground level so the steel would not be sitting on a surface that could retain moisture.
He buried lengths of treated 4x4s directly into the ground to create a 12x20 foot base. It wasn't completely level or square, and the internal 12x20 dimensions dimensions were too large for the ACTUAL base which is smaller than the advertised size of the greenhouse. They were set in with concrete and J bolts, so there was no moving them after that. We had to sister in additional timber inside and outside of the original wood base to give us a somewhat solid base to anchor down the metal frame. We used several L-brackets to stiffen the base and prevent it from teetering.
I confess that I am a hundred pounds overweight, and I have arthritis, so this whole project has been very challenging for me. Up and down ladders, and on an off of my knees all day is unbelievably painful for a guy of 64. This "Three-day project" is finishing its third WEEK, and we are about 70% done.
Once the metal base was basically squared and screwed down, we began the assembly process from the floor plates up. We found errors, both in dimensions that HFT didn't bother to publish, and different dimensions CREATED by combining of two 10x12 frames which were off on the overall length by three inches when combined. At one point I had to cut the base frame 3" on each side, and re-establish one end of the base beneath the already assembled wall. That was no fun, but we got it done. Then I realized that I took 3-1/2" off, and so we had to compensate for 1/2" of missing base along one wall. All mistakes learned along the way.
I also am on a budget that I have already exceeded. He is not happy about needing to spend additional money for things that pop up along the way. A triangle is the strongest geometrical shape, so I want to prevent the side walls from pushing out under the weight of a snow load. I am going to use 3/4" conduit as braces across the middle.
THANK YOU for the great idea of creating channel braces that I can attach to the T-slots in the roof trusses. I will make those and bolt them in, and then use the conduit to link them together horizontally at four points across the house, at the 4, 8, 12 and 16 foot marks. This will all but guarantee that the weight of typical Kentucky snow will NOT cave in the greenhouse.
We are not doing the wooden posts in the ground at the corners, but we have plenty of aluminum extrusion left over from combining two kits, so I am going to go wild with diagonal braces here and there, to stiffen the frame.
We will add LED lights and a fan. Also, since there are four pop-up air vents in the roof, and four more from the other kit, we are going to add in four ground level vents, two on each side that he can open to allow air to enter at the ground level. I don't think anyone has done THAT before. I told him we will probably need to install expanded metal to keep the critters from crawling through the openings. I wanted to install linear actuators for the vents, but he does not want to spend the additional money for that convenience.
All in all, I am learning a lot through this project. I have found ways to improve HFT's original design, such as replacing those #$%^&* Chinese bolts with REAL 1/4-20 hardware. We discovered that we can ADD bolts to the T-Slots by drilling a 1/2" hole through the slot ribs midway. The 7/16" hex heads can then be inserted and slid left or right as needed, to add additional bolts. I will add some for shelving later on.
The HFT design for the door slides is positively horrible. I have redesigned it to work much better, but of course, that required additional money for lengths of aluminum extrusion. Unavoidable expenses. When it is done, the doors will glide open and closed like the wardrobe doors of the closets in expensive homes. 😁
I am (almost) tempted to build another one of these at my house, making the necessary changes and upgrades to make it awesome. For example, I have a CNC plasma table, so I could make 14 gauge triangular braces for the wall to roof transitions all along the house where you used those (shelving braces?) I can create triangular T's at the top and even corner shelves that span to the T-slots of the side ribs for utility and strength.
If I build another one, the door frame will be a solid, STEEL rectangular independent door frame that will NOT tilt like a parallelogram, and it will simply bolt TO the greenhouse at the entry point. The doors will glide open and closed effortlessly.
I can SEE a better greenhouse, but the budget will not allow me to make this one spectacular.
Joe
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