This is from a 40 year single family today. The shingles are no longer shingles so I’m recommending a tear off. 
Something caught my attention in the attic. There are no exposed nail tips in coming through the roof decking in pic1. As you can see in pic 2 they drove screws through at rafter intersections only. Tear off or not, it is a lousy job in my opinion. Anyone agree? 
Erol,
Aren’t those just spiral cut nail that “missed” when the roof boards were originally applied?
Never thought of that possibilty. :neutral: Based on the fact there is zero nail exposure, would you consider their most recent roof job a dud?
Yes, good call. If the nail does not penetrate the roof decking it will back out of the timber due to thermal expansion/contraction.
Regards
Gerry
Thanks Gerry for confirming. Thank you Mike for showing me how easy it can be to miss the obvious.
Roofing nails should penetrate at least 3/4" into the deck, or through the deck if the deck is less than 3/4" thick. Do you know how thick those planks are?
Roofing nails should penetrate at least 3/4" into the deck, or through the deck if the deck is less than 3/4" thick. Do you know how thick those planks are?
No Paul I don’t, but this is the first roof I’ve ever seen that didn’t have any nail exposure throughout the entire underside. That’s generally the first thing I look for in the attic. Especially in the winter when some nails look like icicles from poor ventilation and a buck’s worth of insulation on the floor. </IMG>
Maybe they used staples when that roof was put on.
Not from poor ventilation of the attic but (1) poor ventilation (no or cheap fans, no dehumidistats/timers controlling fans) of the house below along (2)excessive moisture in the house (from damp/ wet basements, stored firewood,etc., hanging/drying clothes inside, dryers not vented ,too many plants/terrariums, etc) and (3) attic/ceiling not properly airsealed for energy conservation.
Take care of the above and the following will happen:
(1) The house becomes more comfortable
(2) The icicles disappear and maybe a bit (insignifcant ) of frost will be seen on the nail shanks/points
(3) energy bills decrease
(4) The existing ventilation will probably be all you need!!
Brian,
Thanks for a more comprehensive list. I know of all the causes but for the purpose of my post I was referring to soffit vents that are covered, but that would be hard to do with a buck’s worth of insulation. It is not unusual in my area to also find homes that lack sufficient soffit ventilation.
The roofers used either 7/8" or 1" roofing nails and probably hand nailed the job.
It does not require to penetratr the plank board decking, as long as the penetration into the plank decking is (don’t quote me on this) about 1/2 " to 3/4 inch.
(Dang, now I have to go and look that up. It has faded out of the memory banks.) I will read through my Master Shingle Applicator Manual again.
I say probably hand nailed, because if using a pneumatic nailer, there would be some evidence of the tips of the nails pushing the decking at the bottom, even without complete penetration.
Typically, on plywood decking and oither engineered decking, which are more common, the nails are always noticeable. You are probably used to seeing this the majority of the time.
Ed
From IRRC link I got here a few weeks ago.
The actual penetration into or through the decking varies amongs the shingle material and ventilation product manufacturers, from what I observed during a real quick search.
Ed
C. FASTENERS:
1. Nails shall be EG type, 7/16” head, long enough to penetrate 3/4” into or through the sheathing board.
2. Staples shall be galvanized type, 7/8” crown minimum, long enough to penetrate 3/4” into or through the sheathing board.
3. Shorter fasteners are acceptable for use at overhangs and eaves to
minimize penetration of the visible underside.
4. Fasteners shall be located as to penetrate through all laminations and the selvage top of the underlying shingle, generally four fasteners per shingle.
5. Additional fasteners may be required in high wind areas.