3 tab shingles & wind resistance

To my knowledge, no 3 tab shingle is rated by the manufacturer for more than 60 MPH.

Question: do you call out use of a 3 tab shingle if the property is in a higher wind zone? Where I live, for example, it’s a 90 MPH wind zone. 3 tab shingles are on at least 50% of the homes around here.

Owens Corrning makes them

http://roofing.owenscorning.com/homeowner/shingles/weatherguard-hp.aspx?seo=goo_|Storm|Wind|_wind_shingles&s_kwcid=TC|22101|wind%20shingles||S|b|8621432988

Those look like architectural shingles to me. That’s not what I’m talking about.

Good question, most areas in the United States are in a 90 MPH wind speed zone including my area and the use of standard 3 tab shingles are also commonly used with standard install. Even though the shingles may not meet IBC 1609.1. My thoughts are, if the roof meets the intent of the local code even if the shingles are not rated for 90 mph. I don’t see a problem. Of course any area in excessive of 90 MPH would then be a concern, and then proper wind resistance class should be installed according to manufacturer’s specifications**.** It all depends on the wind speed zone for that area.

The nailing supplements the wind rating. Double nailing or fasteners on both sides of the tab. The regular nail pattern is one fasteners.
6 nails per shingle in high wind areas. Also plastic cement under each tab adds protiction from wind lift.
You can see the pattern in the attic.

You are correct. I don’t call it out even if conventionally nailed–the AHJ allows it so I’m not getting out on that limb by implying that the roof should be replaced. Probably 50% of them are conventionally nailed around here with 3-tab shingles.

I might change my view if others concur that it’s a problem.

In theory and I’ll say that again in theory the permit application for construction or roofing is required too show that the roof covering meets the wind load requirements for the area in which it was installed. if you are in a 90mph zone the it would be ASTM D3161 <110mph. and nailed with no less than 4 nails or per manufacture specifications.
I remember the good old days going back to the last SBCCI 1997 before Florida adopted the IBC in 2001 you could actually look in the code and find a requirement which in this case required no less than 6 nails. But now that attorneys help write the code it is ASTM this and ASTM that or defer to the manufacture

Storm Nailing

Do not use staples;

Storm Nailing is not required by CertainTeed; however, the installer can use six nails to secure each shingle. In addition, the installer can seal each shingle with four spots of asphalt roofing cement ASTM D-4586 Type II the size of a quarter, equally spaced, but it is not required by CertainTeed. :slight_smile:

6 nails are for high wind areas it’s true, but the most important component in resisting wind is the adhesive strip. If the bond is broken and the wind gets under the tabs the shingle may or may not pull over the nail heads, but the tabs can still crease and tear. Manufacturers are serious about their warranties. If 60 MPH max shingles are installed in a 90MPH wind zone, I’ll bet a lot of them are not going to stand behind the warranty.
It’s so common, I don’t recommend replacement, but if there’s a chance the warranty is in effect, I think the buyer deserves to be made aware of that condition.

In our area, Virginia Beach, VA, the code states that all shingles are to be fastened according to the manufacturers requirements, but no less than 4 nails per shingle, and 2 nails per individual tab.

I believe that the stated 60 mph is what the Warranty covers