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Discussion Starter · #1 ·
On Contractor Talk, one of the HVAC guys was considering buying something called a, "Gantry Crane", which I checked out on Google and have never seen before.

If you are not familiar with them as I wasn't, here is a link.

http://www.lkgoodwin.com/more_info/..._tripod_cranes/gantry_and_tripod_cranes.shtml



Here is my solution for less than $ 200.00



I have moved many Roof Top Units on top of Restaurant roofs, which can be extremely crowded,

You can buy my RTU Moving Kit for about $ 20.00 for materials and about $ 200.00 for the crank handle A/C Jacks I bought from a roofing supply house. I would have to go in the back of my shop to get the brand name of the manufacturer though.

Ingredients:

2 8-12 foot long 2" x 12"s

1 (or more) length of 6" PVC schedule 40 piping

Your own Sawzall and a long blade


Mixing the ingredients:

Cut multiple 12" wide sections off of the PVC pipe

Disconnect all gas and wiring from unit

Place cut sections of PVC next to the length sides of the units curb, keeping enough clearance so they will not bump into the curb

Lay both of the 2" x 12"s on top of the PVC segments

Set up both sections of the crank up HVAC Jacks on the smaller width sides of the unit, using the extension pipes that come with the kit in necessary

Insert one set of jacks on opposite ends of the unit and crank the unit up just enough for clearance over the prefab curb

Once unit clears the curb, gently push the rear of the unit until the rear-most section of PVC is no longer under the 2" x 12"

Go to the front of the 2" x 12" and insert that same discharged section of PVC under the leading edge

Repeat as necessary



If there is an existing gravel roof surface that you are concerned about dispersing the weight onto, forcing the gravel to harm the roofing material, then I would suggest picking up about 4 pieces of 4' x 8' x 2" thick isocyanurate insulation board and 2-4 sheets of plywood to lay on top of the insulation while movement is being achieved.



Best results are obtained on a white thermoplastic roof membrane with a bright sunny day\, while you are wearing sun glasses and have applied adequate amounts of the properly rated SPF sun tan lotion.



I have some really cool photos of us doing just that on a job one time, many years ago, where the Souther Boy PM thought all of us Chicago contractors prices were so high, that there must have been some Payola going on to get the job from the previous PM.

He figured he would F**k with us in his own little way.

It didn't slow things down for even a total of one man hour, once I concocted this little roof top apparatus.

After that, I asked him how he was going to get the units back on the curbs, since the crane was long long gone for several days by then.

We saw eye to eye from that point on.

I'll try to see if I can remember to find and scan those photos in next week. The job was from around the early 90's, when I did it for the first time.

Ed
 

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What we've always done was use a automobile jack to lift up one side at a time. I saw the jacks you posted in your photo on Frey/Race's catalog and almost bought them on the spot but stuck with the car jack.

I've also used crane rental services if there are alot of units to be moved/removed. Last job we lifted each unit and slid a sheet under, and even took one unit off the roof. They showed up on time and we were ready for them and he was in and out in an hour. At first glance it seems like it cost alot being that cranes are expensive, but after figuring it only took an hour to lift and remove multiple units, that really saved a ton on labor.
 

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Discussion Starter · #3 ·
When I showed up on that job in the photos, the units were not supposed to be there yet, so it caught me off guard.

I had to think fast, because I wasn't waiting for or paying extra for a crane that wasn't accounted for in the price.

Ed
 

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Ed, that's a change order and as such you should recieve extra monies for the job. I walked off a large epdm job once because my bid specifically said before any penetrations or curbs are isntalled. I based my price on rolling out an open field. When I got there I saw the pipes and curbs all starting to go in. I told the builder I wanted extra, he laughed, I walked. Guess who's laughing now. I have too much self esteem for new construction.

As it was, you still spent your time moving those things all around the roof and should have been compensated.
 

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Discussion Starter · #5 ·
Grumpy,

When I was a New Construction Whore, I would do anything in my power to get the job done as quickly and high quality as possible.

That particular Burger King had the entire Mansard Roof decorated with Cedar Fancy Cuts.

The price for the material, at THAT TIME was around $ 450.00 per square.

I found a jobber who inadvertently sold direct to me for $ 225.00 per square, so not only did I have the mark-up on the retail price, but the extra 50% in material cost savings.

After I moved all of the units to the other side of the roof and laid out my Duro-Last membrane, I got the PM up on the roof and asked him when he was going to get a crane out to the job site to set the units.

He really had a new appreciation for me after that.

Also, when he called around for alternative pricing, he found out that the Fancy Cuts were not in the same price level as standard cedar perfections, so he realized that the price was not out of this world after all.

I did not know, nor had the diplomatic balls to use change orders on new construction jobs in my beginning years, but have since learned many lessons.

Ed
 
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