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# roofing

## roofing

#1
08-21-02, 06:31 PM
creative nails
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roofing

i'm going to put a new roof on my house ......how do i do the mathmatic to figure how much material i'll need

#2
08-21-02, 07:20 PM
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Join Date: Dec 1999
Location: Northeastern NC On The Albemarle Sound
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Measure all sections of the roof from top to bottom and side to side...length X width = square footage. Convert the total square footage into roofing "squares" by dividing it by 100.
A "square" of shingles is 100 square feet. i.e. 10' X 10'.
There are three to five bundles of shingles in a square, depending upon the type of shingle (three bundles per square in normal 3-tab shingles).
You will need extra squares for starter courses (upside down doubling at the down side drip edges), ridge caps, trim and waste, and matching color leftovers for future damage repairs.
I would add 10 to 15% over the basic roofing square total for the extras.
You will need X rolls of roofing felt to match the square footage (you will need twice as many 30# as 15# felt rolls).
You will need new metal drip edge (length of all edges + small amount of overlap at ends of pieces). Install drip edge under the felt on the downside edges, and over the felt on upside (peak) edges.
You will need rolls of metal flashing (aluminum or galvanized...I use aluminum...won't rust) to cut into pieces for step flashing along dormers and chimney, if you have them.
If you get the total square footage and the total length of the edges, and select the shingles that you want, the roofing material people can help you estimate it all, including the felt buttons and roofing tacks.
Good Luck!
Mike