Installing and nailing down roof shingles is not an easy task for an amateur. Nevertheless, I will present some great information for DIY'ers who want to give it a try at their own risk. Properly layered shingles are the key to avoiding water damage and leaking. Quality roofing nails need to be used to fasten the shingles and to install the roofing underlayment for waterproofing. Shingles may be one of the simplest roofing materials but require specialized and exact rules on how to fasten them.
Improper techniques like nailing too high or too low will either cause shingles to lift and break in high winds or create weak spots between the sheets, which none of us would want.
You will need a hammer, nails (of course) and a utility knife that helps cut the shingle if gets damaged or to resize it. Different types of shingles have different nailing locations. The most used and effective techniques for installing shingles are Four-nail and Six-nail systems. The positioning of the nails is specified according to the shingle type. Choose the right type, size and grade of nail as specified by the manufacturers instructions. The size and diameter of the nails is critical to your success. Go with corrosion resistant nails if you seek quality results. Generally, as you start shingling the roof, lay a row of shingles beginning from the lower left corner of the roof and nail down the shingles as you go along. Nail the shingles from one side to the other so they remain flat on roof. Stay consistent and you will increase the uplift resistance of the shingles. The nails must be inserted well along the sealant between layers of shingles, not too high or low. Use galvanized nails and use four nails per shingle.
Long time roofing experts suggest 5 to 6 nails per shingle. Place the nails 6-1/8” above the butt edge, 1” and 13” from each end ½” from each cutout. Do not insert nails into or above the sealing strip. For shingles in windy areas use 6 nails per shingle. Make sure none of the nails are within 2" of joint of shingle. The nails must penetrate well into the wooden roof deck. If the nail fails to penetrate the deck properly then remove the nail and repair the hole in the shingle with bituminous mastic and use another nail. Try not to break the shingle surface with the nail head and repair any incorrectly placed nails immediately. While using pneumatic nail guns, do not set the pressure too high because the nail will get driven too far into the shingle. Do not forget about the special application instructions for nailing into steep slopes and high-wind areas.
There is no doubt in my mind that it's better to hire a professional roofer to install your homes primary defense mechanism against mother nature. DIY'ers or those seeking to save money- be careful and do your homework.