Raise the (Tent) Roof!

DISCLAIMER:

I am by no means and architect or an engineer.  I am speaking from my own experiences only.  Try this out at your own risk!  Be safe and when in doubt, consult someone you trust about these things.

Safety, safety, safety.  =P

As promised, this post is about how to construct a giant tarp covering in your own backyard.  It's an excellent, inexpensive way to have a massive covering for your backyard that's bound to impress.  As warned, I'm about to get technical.  Real technical.

 Me, my fiance, and my mom standing proudly underneath the tarp we just painstakingly set up.

What You Will Need:

The Tarp:

My backyard space was about 18' x 20'.  To accomodate the center pole, we bought a tarp at 20' x 30' for $90, not including tax and shippin, at www.tarpsonline.com/complist.asp .  It ended up being a little too long, but we made it work.  I dare you to find a better deal.  If you can, post it in the comments!

We needed a stronger tarp than your regular average hardware store tarp in order to withstand the tension we are going to put on it to make the tarp smooth.  After a little research, we settled on a white tarp that had UV protectant coating and was 14 x 14 weave count, 6 oz./sq. yd., 1200 denier (not sure what that means), and 11-12 mill thickness.  It was a very high quality tarp with reinforced edges, grommets all around, and super-reinforced (my made up term, not theirs) corners.  All in all, I was a happy customer.

The Center Pole:

Leveler

50 lbs Qwickrete (~25 bucks)

100 lbs regular concrete (~4 bucks each)

10-15 gal container

2 x 6' 6" diameter PVC pipe

1 x 6" PVC pipe coupler

1 x 6" PVC pipe end cap, unthreaded

1 x 3' 4" diameter pipe for reinforcement

Expanding, high density polyurethane foam (the kind used for boats), also known as hull filler
(I used HandiFoam, which is kind of expensive and one-time use, but works FAST.  You can find the kind where you mix yourself instead at your local hardware store, but it doesn't expand as fast)

Assembling the center pole:

1)  Mix the Qwickrete directly inside the plastic container according to the instructions.

2)  Immediately insert one 6 ft 6" diameter PVC pipe section into the Qwickrete.  Use the leveler to make sure the pole is perfectly straight and and eyeball to make sure the pole is in the center.

3)  Hold the pole straight until the Qwickrete sets (about 10 minutes).

4)  Mix the rest of the concrete directly in the plastic container.  Let dry over at least two nights before setting up your tarp.

5)  Hold the 3' 4" diameter PVC pipe inside the set 6" PVC pipe so that half the length of the smaller pipe is stickout out above the top of the larger pipe.

6)  Fill the set pipe and the inner pipe with high density foam.  Use gloves, as this will get messy!  If using the HandiFoam, it expands A LOT (around 30x's the original volume), so use sparingly.  It reaches its full volume in 20 seconds, so add a little bit, wait 20 seconds, then add some more.  The foam completely sets in 1 minute, so don't panic and hold that inner pipe straight!  You will need to add enough foam to fill to the top of the INNER pipe as well.  To give you a better idea of what can happen, examine the YouTube video link below:

http://www.youtube.com/watch?v=u70Hg0KYvao&p=1906403BEF353135&playnext=1&index=4
(the embed feature was disabled...boo.)

If you're using the type of foam you mix yourself, measure and calculate the volume of the inside of the pipes, calculate the volume of each component needed to fill the pipes, combine and mix the components, then pour the whole amount into the pipes, then wait.  You will have to hold the inner tube in place for a longer amount of time than if you use the HandiFoam, but it might be worth the money you'd be saving.  Read all the manufacturing instructions.  Don't forget to fill to the top of the 4" diameter pole as well!  See the instructional video below:

(this video is nicer to bloggers.  =P)

7)  Add the pipe coupler over the inner pole and snugly around the outer pole.

8)  Put the end cap onto one end of the free 6' 6" diameter PVC pipe section and add the pipe section on top of the set pole, securing it with the connector.  You're done!

Theory:

The concrete holds the center pole upright and prevents the pole from travelling around because it is uber heavy.

The polyurethane foam is to prevent the set PVC pipe section from flexing and therefore reducing the amount of stress on where the pipe comes out from the top of the cement base.  It also holds the inner 3' 4" diameter pole in place and keeps it from flexing.
The inner 3' 4" diameter pole is to reinforce the joint between the two 6' 6" diameter PVC pipe sections.  This pole also allows you to attach the second PVC pipe section without any adhesive and therefore easily remove the top pole and store the whole shuh-bang in your shed or garage or whatnot. 

Do you see the bump halfway up the pole?  That's the PVC connector!

Putting up the tent (you will need 3+ people and a tall ladder):

1)  We started with adding screws to the structures that we would want the tent to connect to.  Screws work better than nails because they won't pull out and are sturdier.  If you want to use your fence, I highly recommend bracing it at each post with a strong wooden stick.  You wouldn't want your whole fence to give out during your party!  Add the screws at about every 2 ft or so.

2)  Using thin nylon rope or parachord, attach one whole length (not width) of the tarp to its supports.

3)  Stretch the tarp out to the opposite side, then drag the center pole underneath to the center of the space to be covered by the tarp. 

4)  Attach the top section of the pole, then slowly tilt the pole upright while the others walk the tarp over the pole.  Once it's upright, attach the other sides of the tarp to its supports.  During this process and the next step, you will need someone on a tall ladder who can reach the top of the pole to push up the tarp from the top of the pole so that it can straighten out.  As you tie the supports, the pole will get pulled in different directions.  Don't worry if you see the pole bending at the joint.  If you constructed it right, it should be ridiculously solid.  Just don't let it stay crooked for a prolonged period of time.

Mr. Tall Guy on Ladder Duty

5)  Once all the sides have been attached, go around the tarp and retighten the lines so that the edges of the tarp are straight within the space, and the whole tarp is stretched so that there are minimal wrinkles.  Work from one end to the other, going back and forth to opposite sides of the tarp.  The more sleek and straight your tarp is, the better and more professional your space will look.  Another thing is: the tighter your set-up, the less chance the winds will destoy your hard work. 

5)  Every morning and evening that the tarp is up, check to make sure the pole is straight.  If it isn't because the winds have shifted the tarp tension, simply get on the ladder, lift up the tarp, and let the pole restraighten. 

6)  Decorate at will.

When the tarp came in, I was so excited, I wanted to set it up right away as a "trial."  In the end, it took so much work, I never took it down for TWO weeks!!!  I'm so happy with my center pole, I didn't even put it away.  It's currently decorated with Xmas lights and allowed me to hang up Xmas lights across my yard.  The pole is a lot of work, but because of that, it's durable, very strong, and is very versatile.  The tarp was folded in a way so that the clean side is on the inside.  That way the next time we use it, we won't have to worry about dirt flying into our food from above.  It had sustained no damages and remained very clean looking.  I will break it out again for my wedding next year, except I will have to rain and cold proof it.  Stay posted!