Greenhouse construction tutorial. How to JDPShack. Options.
John Pandrea
ALWAYS WEAR SAFETY GLASSES, EAR PROTECTION, WORK GLOVES WHEN HANDLING METEL AND A DUST MASK WHEN DIGGING HOLES, MIXING CEMENT, OR CUTTING and DRILLING MATERIAL.
Greenhouse construction tutorial (1) Overall Height
Overall height can be changed by changing the “T” post length. JDPShack is designed with 5 ft. 6 in. “T” posts set 1 ft. 6 in. deep into concrete, for an overall building height of around 9 ft. Using shorter “T” posts will result in a shorter overall height.
In step 52) the “T” post’s length is 5 ft. 6 in., resulting in….
4 ft. sidewalls and an overall height of around 9 ft.
Use 4 ft. 6 in. T posts for 3 ft. sidewalls and an overall height of around 8 ft..
2 ft. side walls is as low as JDPShack can be built and still set a standard screen door at the front/entrance.
If you shorten JDPShack, the bottom girt location can be set lower too. Center the bottom side girt height in between the bottom of the top girt and the ground as long as you keep the bottom of the bottom girt up off of the ground about 6 in.
If you shorten JDPShack below 3ft side walls, you may want to delete the bottom girts as they become more redundant the shorter the sidewalls become.
If you want to shorten JDPShack, follow all directions and when you get to step 53), place shorter T-posts on the ground. Then continue with all remaining directions and JDPShack will turn out shorter.
The side wall covering width and bottom end wall covering width will also need to be shortened.
Beginning with step 160)…a 60 in. wide screen is used for a 4 ft. side wall and bottom end wall run.
Use 48 in. wide screen for a 3 ft. side wall and bottom end wall run.
Use 36 in. wide screen for a 2 ft. side wall and bottom end wall run.
(2) Overall length
Over length can be changed to a custom length, (other than 4 ft. increments), this will require some additional understanding, engineering and calculating. Good luck with this if you proceed. I believe you can figure it out.
Now…
Overall length can easily be changed in increments of 4 ft. according to this tutorial.
The front and back corners will always remain the same, with 4 in. offset “T” posts.
The intermediate “T” posts are all identical and set at 4 ft. on center.
Overall length is determined by how many intermediate “T” posts are included along the sidewalls.
The only issue is calculating the diagonal distance from corner to corner in order to “square” the layout.
JDPShack can be 4 ft. long with 0 mid span “T” posts. JDPShack can be built as long as you like, considering the roof coving lengths available. Up to about 100 ft. long.
Using the a2+b2=c2 formula where a=width, b=length and c=diagonal corner to corner.
If the length is 4 ft. and the constant width is 14 ft., the diagonal is 14 ft. 63/4 in.
If the length is 8 ft. and the constant width is 14 ft., the diagonal is 16 ft. 11/2 in.
If the length is 12 ft. and the constant width is 14 ft., the diagonal is 18 ft. 51/4 in.
If the length is 16 ft. and the constant width is 14 ft., the diagonal is 21 ft. 31/8 in.
If the length is 20 ft. and the constant width is 14 ft., the diagonal is 24 ft. 5 in.
And so on.
Roof purlin overall length will change accordingly in steps 60- 66).
Side girt length will also change accordingly in steps 73-77).
More option information including coverings options, end wall door and opening options, adding rain gutters and more will be added to this section soon.