If I had to vote for the most important accessory of asphalt shingles, nails would be hands down by preferred choice.
Nails keep the asphalt shingles in their place for many years. They protect them against wind uplift in windy and coastal regions.
Consequently, I would harness my frugal instinct at the time of buying roofing nails.
QUALITY OF NAILS
The best option is hot dipped galvanized nails (dipped in a hot zinc bath). Thus, a zinc oxide coating is formed on the metal surface which works as a sacrificial anode.
Electroplated galvanized nails are generally not recommended to be used with asphalt shingles.
GEOMETRICAL CHARACTERISTICS
Shank diameter:
It should be round 3mm. Barbed shanks are preferable.
Shank length:
It will depend on several factors:
- the existing norms
- the type (thickness) of shingles
- if the project is about new roofing or reroofing over all asphalt shingles
- number of shingle layers
- if nailing is near the ridge area etc.
- the type of the substrate.
Generally in U.S.A. the minimum recommended penetration length is 19mm whereas in Europe the recommendation is more flexible.
The massive quantity of nails used in Europe are 20mm long (25mm for ridges) which means that penetration is normally less than 15mm.
In case that the underside of the deck is visible e.g. in kiosks or pavilions, the manufacturer should be consulted for the idoneous solution.
Nailhead diameter:
This is very critical parameter with regard to wind uplift resistance. A minimum diameter around 9-10mm is recommended.
HOW MANY NAILS PER SHINGLE?
It depends on the number of tabs.
For example the normal three – tab rectangular asphalt shingles used in USA / Canada need 4 nails: two above the cutouts and two near the edges.
In Europe, mostly four-tab asphalt shingles are used and the number of nails needed is 5/shingles.
More nails are needed:
- in windy regions
- when slopes are very steep, normally bigger than 200%.
In this case two nails are used above the cutout. So 6 nails will be needed for the 3-tab shingles and 8 nails for the 4-tab shingles.
Chris Strogilis
Civ. Eng. – MBA – DipM
http://maconwaterproofing.blogspot.com
Civil engineer with postgraduate studies in MBA and Marketing
Article from articlesbase.com
Diy roofing and building diy – How to install asphalt roof shingles: Easy roof building diy for your gazebo, outdoor living / outdoor room, patio,garden shed,garage or pergola. Snap a chalk line 160mm out from the hip line and install hip capping pieces.
