Why Are My Roofing Nails Coming Out?

Pearce Services

I was up putting on Christmas light and noticed some fibreglass shingles cupping along the gable end of my roof. I looked to see what was the problem, and noticed that the roofing nails are all lifting out just along the outer most edge, within 2" of the end. There is no overhang, only 2 pieces of 1"x trim boards. The nails are very black and have some graphite like powder on them.

If it is common, I'll just do the repairs. I know the builder dida lousy job structurally on this house, and am concerned that the nails may be loosening due to torquing of the structure.

A second question, has any one ever retrofitted simpson strong ties into existing structures? Is just stabilizing the roof structure an advantage, or do I need to create a continuous load path to gain any structural stability?

doubleaction

Did the nails sink into wood ? Also could be they didn't drive them down enough.

mdshunk

Do you suppose that a layer of ice formed under the shingles at the rake, and lifted the nails up as the ice froze? A little more and more each freeze cycle? Just a guess. I'd look into that before something exotic like the whole house twisting, popping roofing nails. It seems like you'd have more symptoms elsewhere like wall and ceiling cracking. Occam's razor.

house bldr

It's not all that uncommon to see this. Usually the cause is the nail falling in a crack such as sheathing joints or probably in your case cracks between the rake trim and roof.If you have old t-locks that were face nailed to hold the ends down they always work out!It would be easy to peel a shingle back on the edge to see if this is the problem. If it looks like the nails hit solid and are still pulling loose you should look to see that the roof edge is over the felt, not under as this could allow water to blow in on the gable end,get under the felt,soften and eventually rot the sheathing. The shingles are constantly expanding and contracting with temperature changes and will work a nail out if its not solid.

Pearce Services

I think the shingles were slightly concave for some time, maybe since last winter, but seemd to really lift following a recent wind. These nails just started to really lift over the last month, since it has not gotten too cold yet, it could be a combo of old ice related loosening, and a recent high wind, I'm not sure.

interesting thought on the nail finding the seam, but the nails did have some resistence when I re-set them. I'll pull up and repair, and see if that is the case.

Thanks for the help.

dougger222

I've got a couple roofs with this problem both done in the past two Winters.

Never once had staples pop, ever. Stapled for 6 years nailed for last 4 years. Doubled the call backs by switching to nails.

dougger222

People used to get nervous when I pulled out the staple gun so I switched to nails and now have to deal with popped nails.

wbsbadboy

This should help answer your question.
http://www.strongtie.com/literature/c-hw05-r.html

Simpson Strong Tie also has some of the best seminars that I have ever attended. They are free and also come with breakfast for the 1/2 day classes and lunch is included with the full day courses. I highly recommend these to anyone that works in the trades. From concrete crews to roofing crews. All will benifit from their courses. They also offer self training packages for those that live too far from the training centers. If you still want a live class tought by a simpson representitive they will arrange one if you can show enough interest in the area you want to have it in.
Go to simpsonstrongtie.com and look under 'training'

Pearce Services

Thanks for the link, great info. I did not see anything on that catalogue regarding retrofitting existing houses, it all appears to be relative to new construction.

I think removing the soffits and facia and installing wall to rafter connections could be an easy retrofit, but getting access to the 1st to 2nd floor strap areas might be difficult without major residing. will reinforcing just the roof attachment be worth the effort by itself, or does the whole system need to be done for the benefit?

Just a note to justify my concern.....My house is built on an old farm, I have no tree protection, the house is only 14 years old, the house has not seen hurricane force winds yet. but it has had significant settling issues, and the whole house vibrates when the doors close, and the washer machine is spinning. I do not think the builder do a very good job on the structure. I would like to reinforce where I can. If it is worth the effort.

MJW

Nails coming up is normally caused by the wrong size nail. If they are too long they will work out, also if they are too small and don't get through the wood. This is on air nails.

I have seen staples come up also, especially when they are too small, such as a 7/8" through a flashing.

boman47k

I have seen several cases of nails working up in the field, not just on edges or seams. I wonder if improper venting could be a contributing factor.

River Rat Dad

The problem is the nails are in the gap between the trim board. They never went in to solid wood to begin with. Put a new nail in 3/4" in either direction. Put one in immediatly above one popping up and you will see its in to "air"

Ed the Roofer

Regarding shingle fasteners. There are 4 typical most common problems related.

1) Under-driven fasteners
2) Over-driven fasteners
3) Improperly seated (crooked) fasteners
4) Improperly positioned fasteners.

Additionally, improper ventilation may have caused continued and progressively worse expansion and contraction of the deck sheathing. Over 90 PerCent of all roofs done are inadeqately ventilated.

The previous theory about ice dam causation, probably does not hold true as you were describing the overhang on the gable/rake edge of the roof I believe. The backflow of water from ice dams and melting typically affect the bottom or eave edge of the home. Under that scenario, then melted ice would flow under the next rows of shingles and create evidence of interior leak damage. If there was an Ice and Water shield product installed to prevent leakage from ice dams, then when the melted ice, now water, would refreeze under the next courses of shingles. When water freezes, it expands by 25 PerCent in size, and that could possibly lift out the shingle nails.

Oversized nails can sway back and forth, as in a "toggle" switch during normal expansion and contraction cycles. They may still posess some pull out resistance, but not enough to remain properly in place.

The wood decking may have absobed too much ambient humidity and has lost its holding power. A minimal strength would be 40 psf of nail pull out resistance.

Check the attic humidity levels and for 100 percent intake and exhaust ventilation along all soffit areas for intake and ridge lines for exhaust.

Hope this helps.

Ed

Pearce Services

There is no doubt that the ventilation is far from adequate, and we have direct sunlight all day long, so the humidity is a real concern, and the nails are small, 3/4 to 1" max, so under sized nails is a potential problem.

In the spring I think I will re-roof the house, and provice for proper ventilation at that time, at least stripping the old roof will be easy.


Thanks again for the responses

Nail Geek

If you're planning to re-roof your home using nails, I would strongly recommend getting ring shank. This would help you reduce greatly the risk of nails pulling out over the years. I would also stay away from using electro galvanized nails. Pretty much the only benefit of an EG roofing nail is the price...beyond that they don't perform very well at all becuase of the minimal amount of coating that's required to acheive the EG rating. I suggest using at least an A153-D hot dip galvanized roofing nail with ring shank. This way you have a nail that will hold better and resist corrosion much longer.

osborn

Nailgeek- Are these nail available for guns?

Nail Geek

Osborn - yes, coil roofing nails in stainless ring shank and hot dip ring shank are available online with free shipping...at fastenerusa.com

Shingle Monkey

You have to be kidding me is all I can come up with.

Tom M

If any of the nails miss solid wood like in between the gaps of tongue and groove or edges the nail will sweat out from the inside. You see more of this than ever now because many installers dont feel it or care about it while air nailing on roofs.

PlainPainter

I so don't have any of these problems when I hand nail a roof. Call me old fashioned - but the price of not having call backs is worth the extra effort of hand nailing. I suppose there are roofers who have a 'feel' with nail guns, and can tell if the nail really went into something. Sometimes when I hand hammer - the nail isn't going into nothing, and it nails down into something but it will feel 'weak' so I will put another nail above it or something until I feel it has 'grabbed'. I guess on new construction with great new roof decking/sheathing - you can go to town with nail guns. But on older homes and ones especially with the old planks and 1" gaps between planks - hand nailing will resolve these issues. I did a roof on an old tenement structure - a 4 family building for millworkers a.k.a 1860'ish. We went over one layer of roofing, landlord didn't want to pay for a rip. We hand hammered with 1-3/4" next door the next identical structure, but different owner, had another roofing company go over one layer as well - but with nail guns, and now in the past few months with all the wind in the northeast - I would say about 25% of the newer roof has blown right off!