Estimating Shortcuts

[George Gray]

I thought some of the newer folks might find this thread helpful. Experienced rehabbers please add to the thread. We may all take away something new. These are a few of the shortcuts I have learned over the years:

1)Roofing: The tab on a 3 tab shingle is 12" wide and has a 5" exposure. The exposure is the piece of the shingle you see where they overlap. To calculate roof area, count the tabs from left to right. This will be the length of the roof in feet. Then count the tabs from the bottom to the top and multiply by 5, then divide by 12. This will give you the width. Take the 2 numbers and multiply them together and divide by 100. This will give you a rough estimate of the number of squares of roofing material. The roof length can also be used in estimating gutters and siding. Unfortunately, this shortcut won't work on architectural style shingles.
2)Siding: Measure the siding exposure like in the roof calculation. The exposure on most vinyl and aluminum siding is 4". Count the pieces of siding from bottom to top. Multiply by 4 and then divide by 12. This will give you the height of the siding. Then multiply the height by the length of the roof and divide by 100. This will give you the number of squares of siding. You won't be deducting for doors and windows, so this should be fairly accurate. The length of the roof will be also the amount of fascia and gutters required. Measuring from the wall to the edge of the roof and multiplying by the length of the roof will give you the square feet of soffit. The height of the siding will also help approximate the amount of downspouts. These calclualtions can be used for material replacement and painting.
3)Paint: a gallon of paint covers 350SF. New wood and new drywall must be primed, i.e. 2 coats or 1 coat of primer and 1 coat of finish color. Home Depot's paint calculator is here: http://www.homedepot.com/webapp/wcs/stores/servlet/THDCalcInteriorPaintView
a 10x10 room has 320SF of wall area or about a gallon of material. There shouldn't be any waste since you are not deducting for doors and windows. Trim is figured by the LF. 1 gallon of trim paint goes a long way!
4)a 10 x 10 room takes 100SF of flooring or 11.25 square yards of carpet. Don't forget the closets and to add for waste.

These are a few things I have used over the years. They are particularly helpful when you forget to bring a tape measure. I hope some of the rest of you will add to the list.

[George Gray]

Scott W., sorry to be confusing in the explanation. Take the pieces of siding on the wall also know as an elevation, and multiply by the height of each piece of siding, i.e. 4". Then take the total and divide by 12. This will give you the height of the elevation. If there are 24 pieces of siding that are 4" each, the wall elevation would be 8' tall. 24x4=96 inches. 96/12=8 feet. Hope this clarifies it.