Question about roofing nails

Background:

As you may know :wink: I’m getting condensation on roofing nails that poke through the deck of my 7 month old roof. I know why this is happening, and I’m trying to alleviate it primarily through soffit ventilation. If that doesn’t work then I’ll have to go on to ripping out my attic floor and re-doing the insulation.

Puzzling:

But what’s puzzling me about the nails is that some of the new nails are rusting while others are not, sometimes only an inch or two apart!

The new nails (through the deck) that are not rusting have a fairly shiny look. I’m not sure they’re galvanized. The rusty ones of course don’t look shiny any more, they’re just completely covered w/ rust.

The old, old nails that were on the original cedar roof, were banged down through the lathe slats, and look to me obviously galvanized. They have that rough, gray, flat-finish. And not a single one of them has a bit of rust!!! (and I’ve never seen any of them with condensation/drops)

Only the NEW nails get wet, and only some of those are rust.

Are roofing nails supposed to be galvanized? Or some other type of rust-protection?

Does it sound like the new nails used on my roof were correct? Do some contractors cut corners and use cheaper nails that would rust so quickly/easily?

Any theories on why some NEW nails would rust and some other new ones would not?

-Rich

p.s. I can post photos if anyone is interested.

Hi,

There are different degrees of galvinizing.

e.g. nails
On the coil nails there is less of a coating. They are not made to be in contact with a lot of mositure. These are okay for roofing. Since the only time they will be in contact with moisture is if you have a leak.

Hot dip nails

These will hold up without rusting for a long time. Even with constant contact with moisture.

E.g. nails were used on your new roof. Hot dips were used on your old roof.

Why are some nails rusting faster then others. Could be that the coating is not even on all the nails. Or some of the nails are holding water longer. It was not your contractor cutting corners. He was following common practice.

So nobody uses hot-dipped nails on roofs these days? Or at least rarely?

Hi,

Hot dips will be hand nailed.

With the cedar shingle roof you had before, it was necessary to use hot-dips. They would have had the possiblity of coming into contact with more moisture.

OK, so now I know that my situation is largely a result of the nail guns which are in common use. I gather that nail guns are compatible w/ the “slightly galvanized” nails, but not with the “seriously galvanized” hot-dipped nails, which have to be hand hammered.

Q: Is this correct?

New but related question…

I’m working to correct the moisture/condensation problem in my attic (i.e. add soffit vents) but many of the new nails are already seriously rusty. Not just the very tip, but the full 1/2" of the nail shaft that pokes through the deck and it looks like the rust may go further up the nail into the wood.

Q: Can rusty nails cause long-term problems w/ roof? (stains on shingles? leaks? void warranty? etc??)

Also for many of these nails, there’s a greyish/black stain in the plywood deck just around where the nail penetrates the plywood.

Q: Is this staining another bad sign or just a byproduct of the rusty nail?

Thanks as always.

Hi,

You are correct.

The black is a by product of the rusty nails.

You would have to check the heads of the nails to see if they are rusting. They may last the duration. Not much you are going to do about it now.

Where does one get hot-dipped galvanized nails? The only nails I can find in the stores are “hot-galvanized”, which I think is a misleading term.

Hi,

You have hot dipped or e.g. galvinized.

Search box on Internet type in: Hot dipped galvanized roof nail :and you will be able to purchase" HDG "roofers - Tree Island Industries is one company that makes them --I have also seen companies advertise "HDG "coil nails - I really do not do much shingling these days,but the Electrogalvanized nails- “E.G.”- will rust if they get wet before installation,if they happen to be left exposed to a rain storm ect…excessive attic moisture from a warm attic and cold roof can cause them to rust,low pitch roofs that hold water longer can cause the heads to rust ect…They will still last quite a while,how long I really do not know , I think they are fine for the life of most shingle roofs, one has to keep them dry before installation to help avoid rusting…Most of these are from China…I believe the Tree Island brand is made Here USA, they are a much much better nail that holds up very very well to excessive moisture conditions,I have used the Tree Island brand ,excellent nails,ordered thru local Roofing Supplier,but anyone can order them online… Plus have you ever noticed how easy the heads will break off the “E.G.” nails if you have to pull them out for a repair ect…

Rpr - How did it go with your roof? Did the soffit ventilation fix your problem? Once the ventilation was fixed did the nails stop rusting/dripping?

Wow, that’s a blast from the past! Let’s see what I can remember. Yes the soffit vents were absolutely key! (I had to do it mid-Feb w/ feet of snow on the ground, but it was completely worth it) And I’m pretty sure the nails stopped condensing soon after, at least I don’t recall being concerned about it in the years since then. I also had a scary mold problem develop after the new roof, which was out of control until the soffit vents were installed. So yes, I would recommend soffit vents!

Answer. I would bet on that all electro galvanized coil nails are made in China. Hell, even hand bangers are made in China. Thus, just like cars, they use recycled scrap metal to make them. So, the rust twice as fast. Just like cars. I bet the old 5 penny galvanized box nails used on the old cedar shake roof were infact hot dipped galvys made here in the good ole U.S.A. Ventilation is a problem, it wasn’t was the old shake roof. However, since the invent of plywood, ice n water shield, & insulation your house might be to tight & condensating(sweating)from the inside. Ridgevent, soffet vent, & maybe proper vent(depending how its insulated?)would be your remedy. Make sure the eaves aren’t over stuffed w/insulation.

That’s right on as far as our roof ventilation goes. Before with the shake roof underneath asphalt shingles, it breathed more. But then the new roof was much more air tight, which led to condensation & mold. Even with a ridge vent it didn’t breathe enough… until we added soffit vents. And yes made sure there was a decent gap of insulation at the eaves. The nails were not the root of the problem at all, their rustiness was just the symptom of the lack of ventilation.

Hope this helps someone who might have the same problem some day after they put a new roof on. :slight_smile:

This is not true. Chinese or scrap metal has nothing to do with rusting. Steel rusts just as quickly if it is made with low quality or high quality steel. Rusting has everything to do with the zinc coating on the steel and how thick it is. Just wanted to clear that up.

Kestas, say what u want but I disagree w/u & don’t believe it. Nails are junk these days compared to what they used to be.

I’m a home owner not a roofer but in my case it’s clear…

The old nails that are still poking through my lathe look very zinc/galvanized and unrusted. The new nails that were used on my 2006 roof job that are poking through the plywood are very rusted.

It seems to me the new nails are inferior. I just can’t say if that’s because the roofer used cheap/incorrect nails, or because good nails these days are hard to come by.

Off topic a little, but about 15yrs ago the Boss got a deal on a whole pallet of 50lb boxes of 1 1/4 eg roofers. Marked “made in Poland”. First time the gopher (Ray) brought a box out to the job I opened it, looked at one real close and said “damn Ray. these polack nails have the head on the wrong end!” Sure as rain. he grabs some and starts looking at them too. Good times. :lol:

Ha, ha, ha! Great one rooferman. To the homeowner, i’m not saying your guy used cheap or inferior nails. I’m just saying 90% of todays nails are junk!