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Thursday, December 30, 2010

How To Measure a Roof

Everybody knows that when roofers die they are reincarnated as architects. The deep seated emotion of revenge has resulted in a steady climb of complexity in roof design while basic math skills have plummeted so far that we need immigrants from third world countries to figure out our stuff.

Take for example computers. When you call the help center you never hear a Southern or Brooklyn accent. If you ask them what time it is they will give you the weirdest responses and sometimes even get the date wrong. They used to come over here but now they just stay home an globally commute from home.

Despite all this we are still trying to measure roofs ourselves but are doing a disgustingly bad job of it. Back in the day (I really don't get this colloquialism but it seemed to be an appropriate time to expound it) we painstakingly (looks German) used step by step methods to accurately decipher how much of everything we needed. But then some yokel over at State Farm came up with the simplistic 10% or 15% waste catch all system that leaves a lot to be desired. Yet they measure in inches and we can't buy roofing that way.

Why you might ask? Why to screw everybody a little at a time. Just like they can't remember that a few years ago a 10% on 10% general contracting fee was 21% and claim it was always 10% plus 10%, resulting in a 1% loss (20%). With these Enron accounting practices applied to billions, you might see how it can add up.

Now I'm not jumping on State Farm. They're really a great bunch and do a very professional job. Really. And everybody ran with this new system and again claim that is the way it always was. Sounds Orwellian to me.
Here's the story du jour: I tell this green adjuster that his math is off. The house is very cut up and there is more ridge on the house than 15% above surface area. It's somewhere deep in the Delta area around Star Date 1987. I finally grow tired of arguing with this simplistic automaton and tell him that I am a little more advanced than most roofers (and adjusters for that matter) in math. He boasts that he had a math degree from North Texas State. I responded "a state school, huh?"

That conversation ended. We roofed the house, saved our invoices, and then went beyond the pale. I sent a multi colored series of sketches breaking the roof into sections and showing how the theoretical pyramid could be extrapolated from this rather unusual three dimensional polygon. I think if it had been 5% more cut up we could have solves some time/space continuum problems and solved world hunger, which every attempt up until now has only caused more hunger. Conundrums are not a musical instruments.

This meat head with his degree was from State Farm but I beat him the old fashioned way. I was right. I also used a little General Sun "Art of War" tactics. I waited for him to be reassigned into another quadrant and then I attacked. Phasers at full strength. Insurance companies hate it when you roof without an agreement on price. They don't want to "adjust" after you have a go. But sometimes matters come up, like shape, size, volume.

Now to the point. Measuring is not an art. It is a science. There are several ways to measure though. Counter intuitively the most accurate is from the ground using a pitch factor. Most roofers, if they still measure, measure from the roof and ignore the eccentricities. They measure a three dimensional object using two dimensional tools. As they lob off sections with rafter times length methods, they ignore the raided areas inside the valleys. I know words fail me here so just trust me.

If you measure the High Noon shadow, or footprint of the roof, that is the foundation plus overhang, and multiply that flat area by a pitch multiplier, you'll have the surface area. Now the insurance companies want to add a flat tax of 10% or 15% whether the house has ten feet of valley or 200 feet. Hip house receive the larger amount of 15% because hip is cool. Gables are factored at 10%. Yet the same floor plan may have different roof cuts creating greater need for valley, hip, and ridge usage.

If you are attempting to measure for the purposes of a very expensive roof material, the simple way is disastrous. Not having enough ridge might leave the roof incomplete because the materials are in another galaxy. That's when you add the ridge linearly, calculate the amount of waste for valleys, hips, and rakes with however much will be lost in the cutting. Tile and stone coated steel roofers measure the rafter length and divide the number of courses it will take, including the fraction of a course at the top as a whole, because we can't buy fractions of courses.

If you are roofing a small short mansard, the ratio of starter to rafter length will be all out of proportion. A hundred foot rafter need less starter in terms of percentage than a roof with only one course of roofing. Half the roof is starter (the blind shingle underneath the first row that keeps the water out of it's end joints).

Nowadays we often measure from the sky. We don't let someone else do it for us like a lot of companies do. We still need to go out there and look around so we can do it cheaper by taking a few measurements to give us a ratio with the pixel count. Then we measure and add pitch factors.

I wonder is some Dallas roofs are measured from India or China yet? So sad many can't even do that for themselves anymore and have to outsource measuring.

This is boring stuff so I'm going to quit now. Later I'll go through measuring step by step.

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