Nails popping up through shingles

My fiancee owns a two story house in Atlanta. This house is 60 years old. The rafters are decked with 1x6s. In 1994 she had the old shingles torn off, and reroofed it with architectural shingles.
I go up on the roof once or twice a year to clean off leaves, look for damage etc. Every time I go up there two or three nails are popping up through the shingles. These are the old 6d or 8d box nails. Sometimes they will be sticking up a half inch above the shingle. Sometimes, I can see a bulge in a shingle where the nail is starting to emerge.
The house has gable end vents, and ridge vents, which I installed. The house does not have soffitts.
What I have taken to doing is, I pull the nail. I have some 3 1/2 inch deck screws, and I screw one of them into the hole. Then I patch the hole.
What is causing these nails to work their way up? The roof has not failed, it is not leaking.

http://www.forbiddenplanet.co.uk/images/D/D4758.jpg

Hi,

You are doing the right thing.

The nails are loosing up. May be the nails have rusted enough that the nail is not as thick as it used to be.

WTF Tar Monkey ??

I thought…gremlins with wee hammers knocked nails back out…

haha

looks like a guy who just finished a cold ap XD

keep up the good work
mr simonkenton.
gives ya sometin to do.

gweedo.

The nails are not rusted. They are intact.

I am fairly certain that wood shrinks after a time as it dries out. In any case I don’t think it’s something you can prevent if that’s what you’re asking. As far as fixng it? Yeah, you’re doing the right thing there.

I went up onto the gremlin infested roof last weekend. There were NO nails popping up. I hadn’t been up there in seven months.
That is the first time there have been no nails popping up in six years. Maybe the gremlins have realized that their ass is whipped.

It could be the gremlin…funny stuff TM

The nails that are backing out are ones that missed a rafter. Heat backs them out.

with changes in humidity the 1X6 boards cup. that is the edges of the bords lift or curl in the short direction working out the nails. just keep on replacing them.

i agree that its due to having the 1x6 the due cupple . how old is the roof? if its due for a new roof ill be glad to give you an estimate i am moving to atlanta on august 9 th .

Drive a 1 1/2" roofing nail alongside the 8. Let the the head of the roofing nail hold down the deck board. While this won’t give you great holding power as far as the board is concerned, it will keep the nail down.

This BTW is why I am tired of fucking w/ plank boards. If you fix 'em and roof 'em, you just can’t fix 'em well enough nowadays.

Layover 'em all you want.
W/ 2 nd layer of shingles, a skin of plywood or OSB etc.
But it is more of pain to re-use them anymore.