Finding sq ft on this roof?

Ive got to go look at a large roof and house wash tomorrow morning and trying to figure out how to find the sq ft of this roof seeing as its pretty complex. I have always used measure map pro app but not sure how extremely accurate it is with something like this. Ive got roughly 5500 sq ft with the app, house is about 3200 sq ft from what im told. I have attached a picture for reference! little%20street

Tape measure.

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Do you have a picture of the back of the house

i do not. I have not been to this property yet i just pulled this picture online… I would like to get a general idea how i can get sq ft before going so i can put together the estimate while im there. Like i mentioned, i frequently use measure map pro but im not sure how accurate it is for a roof like this.

I would ask the customer if they have a build book. That looks like a nice place I’m sure a builder who is doing that caliber of work would give them one. It would have the square count for the roof. 100 square foot in a roofing square easy math

Thats a good idea except they have lived on this home for over 20 years… if they had one i doubt they currently have it but ill ask. Also they informed me the home has not been washed in 17 years and the roof has never been washed. He also mentioned that “everything you guys have ever seen on a roof is probably on my roof” so i can only imagine what ill be walking in to!

I would just get as close as you can without investing hours into measuring and calculating and then throw like $500-$1000 on top to cover all of the weird stuff. Time is money.


Just saw your last reply. Make that $1000-$1500 if it’s as bad as he says.

Our roof pricing varies any where between $0.25-$0.30 sq/ft. If its as bad as he is making it sound it may be higher per sq/ft. As of right now going off the comments he made im already figuring in $0.30.

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Damn. Where are you in the world?

United states of course!

If its truly that bad and at least 17 years old I wonder if just needs replacing. We dont wash roofs that we estimate need replacing in 3 years or less. Not saying it should be anyone else’s policy. But we have partnered with a high quality roofer who does phenomenal work. He always gives us a 5% referral. It’s a win for everybody

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If you decide to go forward with it, remember to charge accordingly. If you decide to do as The Innocent One always says and “run away” I’d go with what @Firefighter4hire said and tell them you’d recommend not spending the money on something that should really be replaced.

we are always extremely up front with our customers and that is something they appreciate. I cant tell you how many times we have recommended only doing half the work they asked because it simply didnt need it. However, i will go and see this roof tomorrow and let everybody know how we make out!

I was thinking x2 for pain in the you know what aspect!.

Just take your perimeter footage and make your adjustment for the average pitch. You’ve got everything from a 4 or 5 to probably a 16 on there. Most of it doesn’t look too bad. $.30 ft should be good for you.


I go by roof footprint/perimeter and adjust the price per sqft according to a few factors.

  1. Can I walk it?
  2. Does it have gutters?
  3. Vegetation risks?
  4. Severity(if I decide to look in person, which I’ll only do for unwalkable jobs)

The more strikes it has against it, the more it slides on up the price scale.

I couldn’t imagine trying to figure out actual squares.

Keep in mind I’ve only been doing this for a little over a year but I think I learned from some of the best.


I use a software called Xactimate to find square footage. We draw up the roof and it gives us exact size. It has the ability to download region specific price lists. It’s the same software that 90 percent of insurance adjusters use, so it keeps us on the same page when negotiating claims. I don’t believe that washing a roof requires as much precision. If you, miscalculate and have to wash an extra 5 squares, it doesn’t really affect your bottom line much. Having to pay a crew to tear off and install the 5 extra square, plus the cost of material could be a 1000 dollar or more mistake. However, if you want to figure exact size using Google Earth, you’ll have to account for roof pitch. If you have a roof footprint of 30 x 50 it would be 1500 sq ft. That would be good if it were a flat roof, but if it’s a 12/12 pitch, you would need to multiply by the proper slope factor. The slope factor for 12/12 is 1.414. Multiplying the 1500 x 1.414 would actually give you a roof size of 2121 sq ft. over a 600 sq ft difference. These slope factors are found on most framing squares. They are used when determining rafter lengths.
Or you could use a company like Eagleview that does all of this measuring legwork for you. We sometimes use them on large cut up roofs, but like I said, I believe being this precise is way overkill for roof washing.


This is one of the reasons we partner with a high quality roof company. First if we have questions about size he he measure it for 50 bucks plus we have learned to measure roofs the right way on a job that size that is cut up like that you could be cutting yourself short or over charging customer. Learn to do it the right way or pay some who does in the end you and your customers will be happy guessing is for amateurs

I disagree that “guessing” is for amateurs. I would say that having to have a roof measured out to the square foot for you to give an accurate quote is for someone who hasn’t done a lot of roofs. I would think that someone with experience could take a look at just about any roof and give a reasonable estimate.