I mentioned as I usually do that there were exposed nail heads on the roof and they should be set an sealed. The contractor that did the roof provided installation instructions that allow “Exposed Nails”. While this has nothing to do with the exposed nails on flashings and boots it still is new to me. I have never seen this before. Everything I have ever heard is they should be sealed. I wanted to hear what others think about it.
The contractor is correct, the shingle will self-seal around the nail and so it’s not necessary. I gave the company a quick call and talked to “Pete”. He did mention that the shingles are able to withstand severe winds so using the hidden nailing is fine but some will still surface nail anyway. You’re not getting a lot of rainfall anyway, so I wouldn’t worry about it. I would personally not surface nail if wind wasn’t an issue, I wonder why they did?
The instructions seem to be for a ridge cap only.
The company called it standard method of installation but I’ve looked at several brands and the Asphalt roofing manufacturers association and they all state the nails should not be exposed and if they are they should be sealed. The NACHI info also stated the same. I think it just makes sense to seal things when your talking about water. They are for the ridge cap only but if it’s good for the caps why not the flashings I guess.
These shingles are SBS (Styrene-Butadiene-Styrene) which basically rubberizes the asphalt in the shingles. That is the reason it can go without sealant, because it has more elastic properties. A typical shingle is deformed drastically when a nail passes through it, but the rubberized shingle will spring back around the nail and seal it.
Like you, I would either want the nails on my roof sealed or not exposed at all, but the contractor is correct.
That being said.
Nail lifts at the peak and hip become concerns for blow-off shingles.
Then the gap is open to weather intrusion.
If they are raised.
SUSPECT CONDITION. Lifted, loss, non-anchored to the deck, fasteners on the roof deck plain-----yada yadaallow the shingle or cap to be blown away.
The appropriate fasteners for shingles are barbed, or ribbed shank roofing nails and must penitrate the deck by a minamum of ------( you look up the depth)
RECOMMEND: A qualified roofer reset the shingle fasteners with a larger dimension ribbed or barbed shank in the same hole caulk or move the shingle cap, fill to hole with caulk and reset the cap 1’ further down the ridge, peak, etc…
Although manufacture allows exposed fasteners on SBS roof peak shingle installations all roofing system should be inspected yearly.
Kenton just finished more material for INACHI members.
take a look at it.
Fastener requirements are found in IRC code Section R905.2.5. Fasteners shall be long enough to penetrate the roof sheathing a minimum o**f ¾” or through the thickness of the sheathing. **Fasteners shall be of corrosion resistant metal.
Follow recommended manufactures installations.
Hope that helps.
If the shingle material is elastic enough, it will prevent moisture penetration due to thermal cycling of the fastener shaft and moisture cycling of the roof sheathing, both of which can combine to back nails out of holes.
Your like an angle with your narrative Kenton.
A pleasure to see you on the board Ken.
You are leaving out other other impotent elements to causes of thermal cycling to wooding decking in attic spaces.
- Poor venting practices.
a. bathroom venting in attic spaces for one.
I might be wrong but I witness this misunderstood practice last inspection. yesterday. Many times before that also.
The rusted fasteners tell me the life history, Or the decking underside, rafter or truss members when observed for signs of RH.
- Nails that are not set properly.
a. short set fastener b.fastener anchorage due to barb-less ring-less shanks, c., nails in deck separations from poorly alined sheathing, etc.
I have photos somewhere.
There is more to hypotheses but you get the fundamentals of my theory.
I do the full attic space.
Even engineered trusses. You have to be a contortionist.
Maybe that why the ladles enjoy my bedside manner. HA HA HA
Many reasons for nail lift Kenton.
Poor venting practices contribute to expansion and contraction of most materials.
So - the ridge shingles can have exposed nails?
Why not seal them? Roofing technology is changing on a regular basis and often roofers will go back and say the way we did it is not the way we do it now.
Rubberized material doesn’t stay rubberized for an indefinite amount of time.