I'm a retired civil engineer living in Sun City Hilton Head, SC. Retirement is great! But, sometimes it doesn't seem like I retired.
My friend of 25 years, Bucky, moved here when I did more than three years ago. A while ago Bucky asked me to take a look at what his home inspector found. (Bucky had a home inspection done as he was nearing the one-year anniversary of buying his new house.) The photos at the bottom show what I saw. These are (valley) roof trusses sitting on top of the main roof trusses. Wow! It looked like I could kick the top (valley) trusses right off the bottom (main) trusses!
The building code for Hilton Head requires that a house be capable of withstanding a 130 mph 3 second wind gust. I got to thinking, "How many other new homes are like this?" I went to Pulte Homes (the builder), Beaufort County SC Office of Building Code Enforcement, and the SCHH Community Association. Pulte chose not to respond. The Community Association said that their charter doesn't permit them to address "house issues". Beaufort County Office of Building Code Enforcement said that they "are aware of the problem" and that "trusses will strapped and installed per code , including houses already completed". That was in January 2007.
When nothing happened, I went to our local newspaper, The Island Packet. They ran a series of articles starting in April 2007. In May Beaufort County requested that all homeowners in Sun City who are concerned about their roof to contact them. They received over 2,000 responses. As a result the County contracted for limited re-inspections on roof truss connections for over 2,800 houses here (built between 2004 and early 2007) because Pulte decided to stop installing hurricane clips on roof truss-to-roof truss connections in 2004.
Truswal, a roof truss expert, recommends that hurricane clips be installed at the ends of valley trusses and at every other connection in between. Before 2004 Pulte included Truswal’s drawing (showing these recommended locations for hurricane clips) in their construction drawings.
According to Pulte's engineer, two 3.5-inch long 16d "toe" nails can be used instead of a hurricane clip. The re-inspections revealed many bad connections (one nail, no nails, protruding nails, short nails, nails that completely missed the truss underneath, nails driven right on top of each other, split wood, gaps between the top and bottom trusses, etc.) Pulte's and the County's "fix" for the defective connections was to insert a "toe screw". They also found houses with missing bracing and some missing trusses.
Pulte decided to resume installing hurricane clips in their new houses that they're building here, but Pulte refuses to install them in the houses that they built here in 2004, 2005, 2006, and early 2007.
In my research I discovered a March 2002 report written by Dr. Lawrence Twisdale, PhD, PE for the state of Florida entitled Development of Loss Relativities for Wind Resistive Features for Residential Structures. This report states that: (1) hurricane clips have been an industry standard since the mid 1960s; (2) toe nail roof connections shouldn't be used in hurricane-prone areas; and (3) a hurricane clip is more than twice as strong as a three nail toe nail connection. (Pulte's spec calls for two nails). Dr. Twisdale also says that "putting screws into split wood may not be adequate".
Googling "roof hurricane Pulte" will get you newspaper articles and blogs about this. All the same, I'd rather be golfing. But you do what you gotta do.