Measuring roof perimeters

Well I had to measure a roof perimeter today for a wind mit and I have a question for you pros.

Do any of you use a laser device? If so do you just point to point a then to point b and move on?

If not how are they used?

How many stories high can you measure from the ground. My plan is to measure the fascia.

Can you see a dot on your target for accuracy?

I used a rolling wheel today and I can see it’s future limitations especially on two story structures.

Is anyone using a different method that works well for you?

Are there any problems with using the laser in the manner I am describing or outside in bright sunlight?

If you use one and you would recommend it please let me know what the model is and the approximate cost.

Any input for measuring the perimeter of a structure would be appreciated. Thanks in advance.

Lasers are limited, you need a item to point it at. On a plain square house it could be difficult if not impossible. Some of the better models will figure the hypotenuse and in theory this would work to measure the fascia. I use two different wheel types, small and large. I use the small one to measure flat roofs(from the top) and the large wheel through the yard. You could also measure a wall by holding it side ways instead of on the ground. One of my inspectors is an appraiser, he uses a tape measure and a laser.

All that being said, I am thinking of buying a laser measure device also. Probably a cheap unit from Home Depot about $100.

let us know if you get one and try it out.

Thanks John I will let you know if I get one and how it works.

If anyone has any ideas please let us know.

-For Broward county the tax appraisal’s office has the exterior wall layout with dimensions for most homes.
-I have taken an index card and taped it at an outside corner and let it hang out beyond the wall to have a place for the laser to target.
-The laser device I have when placed flat on the wall doesn’t let the laser go down the wall enough so I place a small spacer (small piece of wood shim) on the back of the device to bring it off the wall just enough to shoot further down the wall.
-if all the soffits extend out the same on the house just measure the perimeter walls. Your only getting a measurement to see if the 10% rule applies right?

Yep the 10%.

I see how you are saying it works. I was hoping to point to point A then point to point B and get that distance. I will not get one if I have to do it like you are saying. thanks for letting me know how that one works. what model is it so I do not get it.

If anyone knows of a model that will let me point to point A then point to point B and get that distance.Please let me know.

I use a wheel measure but I saw a demo by a Bosch tool rep and they have a sweet little handheld device that does the calculation you need. I think it was $300.00 approx. Kinda expensive but I have had good luck with Bosch tools.
PRP Home Inspections

Thanks John i’ll try to find it. Any idea what it is called?

Hey Michael,
I forget what the model was but I saw it at a Lowes in a demo. The Bosch rep said not all Lowes would carry it. It was as small as a cell phone and did some amazing stuff.

I have used in a quick analysis to get the building square footage off the county website to save time in determining the perimeter linear footage. To give you an example on a 3000 sq ft home. That would be 60’ x 50’. That would equate to 60 +60+50+50=220’. I use it when it’s not close. It doesn’t include overhang which creates a buffer.

Michael, all laser’s need a target that they can hit, otherwise it is unable to measure distance.

I understand that. I think I heard somewhere you can point to object A then to object B and it will tell you the distance between the 2 but I may be mistaken.

I would like to walk the perimeter of the house and and measure the roof line from the ground.

The old fashioned way still works…a ladder and tape measure should already be a part of your tool kit :wink:

I would like to be able to do it in under a day. :smiley:


To calculate the roof perimeter just measure the house at ground level at the drip line and add a correction factor for gable ends. I have attached an example with a gable end factors for common pitches.

Thanks, i’ll check it out.

Everyone: I am still looking for the device if it exists.


I read the other posts an there are no cheap electronic measuring devices that will give you the the distance from Point A to Point B when facing the object like in the picture. Unless you buy a $20,000 electronic surveying system that requires someone to hold a reflective mirror at each point, which will give you the coordinates of each point then do the trigonometric calculations to get your answer. For the accuracy you need for your forms you could just about pace off the perimeter and adjust for gable ends and put that $100 your were going to spend for an electronic tape in your pocket.

The way we do it, not that yours is wrong;

We measure as if the roof was flat, ie gable bottom cord and fascias of flat or hip. York teaches this in his class and the form does not specifically state either way. We do not calculate or include the pitches.

:DThanks guys.

Please hop to it. :twisted:

I agree. For lasers to work they must be reflected back. In order for a hand held laser to caculate the distance between two points it would have to know the angle that you turned between point “A” and point “B”, since the distance would be calculated using triangulation. In order for this to be accurate, the device (laser) would have to remain stationary while turning the angle. Most of these simple lasers that measure distance between points are placed in line with the distance to be measured – ie held on an interior wall whereby allowing the laser to bounce back from each end wall. This scenario doesn’t exist in the field. I don’t think you will find the miracle device that you are hoping for.

Damn, I really want one.:smiley: