Need Tear Off Advice

We haven't torn off a flat commercial roof in 18 years, and it was 10 years before that that we did another one. I'm like a newbie on tear off and could use some advice.

One roof is 320 SQRS gravel, the other is 450 SQR mod bit. Both have 2 layers. The mod bit has steel deck and the gravel BUR has concrete deck.

We will put 1.5" SPF on the concrete deck after priming, and Densdeck and 1.5" foam on the steel deck.

Single roof cutter vs. double? Are we better off buying 2 singles rather than 1 double cutter?

Cut roof into 2'x2' squares, I assume?

On the steel deck, adhering the Densdeck is a lot more expensive, is there any reason that is favorable to mechanically-fastened?

Most of our tear off equipment was manufactured by Garlock, sometime back we were called for s resdiential reroof it was a 1/2x3/4 24" wood medium shake, anyway the owner of the house was Mr Garlock himself we went back with a 3/4 x 5/4 western red wood sake in cuding all copper flashings and trim work after talking with Mr Garlock we started to buy more on deck equipment thru his company we had every tool in his catalogue in 2005 we completed our final hot job since then every hin has been either Singleply or metal oh how I miss that hot work lol as my one calls me an old dinosaur it also took me years after windows came out to convert all my software I guess I don't like to try new things lol

http://www.rooferscoffeeshop.com/rcs/users/andyrosco/2014-10-03 11.59.37.jpg

This is our Reeves tear-off machine which we use to rip out the layers of insulation board after we have cut it with sawzalls. The existing tapered system we are removing is from three to twelve-plus inches thick.

We first remove the BUR/gravel by hand after cutting with roof cutter. Then we saw and remove fesco board.

http://www.rooferscoffeeshop.com/rcs/users/andyrosco/Roof.Cutter.jpg

http://www.rooferscoffeeshop.com/rcs/users/andyrosco/Low.Rider.jpg

In the DFW area we are able to tearoff, apply ISO board insulation and dense deck with TPO at rate of four to six squares per day.

Consequently a standard single 9-13hp single roof cutter is satisfactory for our current needs, but a "Low Rider" roof cutter as visible in upper right of pic is nearly invaluable, as it will cut below these units/pipes 15" above roof surface.

If there is a lot of fesco board to remove, be prepared to spend a lot of quality sawzall time cutting thru it! 24"x24" max, unless y'all are full of energy!

In second pic, low rider draped by piece of EPDM, but you get the idea about its versatility. http://www.rooferscoffeeshop.com/rcs/users/andyrosco/2014-10-28 08.05.27.jpg

Those guys appear to be in Ohio only, but a google search for "roof cutter rental texas" returned a good number of results.

In the late 80's early 90's I rented them a company called Phillips-Day-Maddox.

It's been about long, so I have no idea if they still do this, or not.

Thanks guys.

I wish could find a tear off crew to come and do the tear off for us, I just don't care to do them. Too much specialty equipment needed for jobs I don't intend to do much.

So, who is it that rents roof cutters?

We used a a single and a double roof cutters plus a roof ripper if the deck will support the weight of the RR tractor tear off was our speciality lol Before our many code changes a metal deck was considered a nailable deck most our metal decks were 24 or 26 gauge, we were a old line hot roofing company, prime, insulation then 3 ply glass with an SBS cap sheet lots of work but we were real roofers lol

You'll be much better off with the biggest, baddest Garlock double than with a single, but asphalt and gravel are hard on intakes, engines, bearings etc. and you'll want a back-up.

If you see many of these in your future, buy two, and get a low profile cutter for areas in tight penetrations.

Or... just rent them. But I'm more of an "own it" kinda guy myself.

As for the dens-deck, I would think that adhering the DD would actually be less desirable. If you MF the DD, you'll have a small degree of separation between the expansion/contraction of the steel, although, I think 1.5" is pretty light. An R-9 on a steel deck is highly inadequate, in any north american climate zone, and I don't think it's strong enough to provide long term resistance to thermal stresses. 3" would provide much more rigidity and the added R's would reduce the amount and severity of temperature swings to the inside of the building, thereby reducing the Exp/Cont factor.

My $0.02