Expert: Stephen Major - 5/31/2007

Question
QUESTION: I just had a deck built 2 months ago and noticed that all the nails are starting to rust.  What do I do?  How long will a deck last with rusty nails?

ANSWER: Celeste,

This is unfortunate.  The best nails for exterior decks are either stainless steel or hot-dipped galvanized.

It is possible that your contractor used a nail gun, which usually requires nails that are thinly electroplated, and will not hold up well in a high exposure situation.  Or, the zinc (galvanizing) chipped off of the nail heads during hammering.  The worst case is that the nails are not protected against corrosion at all (plain steel nails).

At this point it is very difficult to remove the nails without damaging the deck boards.  One alternative is to stain the deck with a solid or semi-solid stain, being sure that the nail heads are sealed.  This will add some life to the nails.  

Without knowing more about the type of nail and the type of deck board it is difficult to guess how long the deck will last.  If you know this information, please let me know.

If any nails work their way up from the deck surface, be sure to pry them out and replace with higher quality nails.

Please let me know if you need additional information.

--Steve Major

---------- FOLLOW-UP ----------

QUESTION: Thank you for that information.  He did use a nail gun.  And the wood is the typical pretreated deck wood.  I may be able to get a nail out, or find one in the grass around the deck. How would I find out what kind of nail it is?  

Answer
Celeste,

Thanks for sending the photos.  The nails are cheap electroplated gun nails.  They are inappropriate in this application.  Unfortunately many contractors are under the mistaken impression that such nails are adequate for a deck.  It is apparent from your photos that the deck contractor is not very conscientious and is not a good finish carpenter.  The rough factory cut on the end of the visible board, with a label staple and part of a tag still in it, speaks volumes about the lack of quality.

The nails are very, very difficult to replace now.  Getting any type of prying tool on the nail head will damage the decking.  Pounding the boards up from behind/below will likely not work either, since the coating on the nails tends to make them stick tightly.  They may just rip right through the boards if you try this.

I'm sorry that I don't have better news.  I doubt that your contract is worded in you favor here, so getting some relief (replacement or money back) is likely very difficult or impossible.

--Steve Major


Celeste,

In order to work properly, most rust-resistant gun nails have a thin smooth coating of electroplated zinc or similar material.  The thick rough surface of a hot-dipped nail would not operate in a nail gun.  Plus, many contractors purchase imported generic nails that are often of inferior quality.  So it is likely that the nails in your deck have minimal rust protection.

To compound things, some wood treatment chemicals can accelerate the rusting process.  For this reason, it is highly advisable to use stainless steel nails in treated wood, especially with a nail gun.

If you want, send along a close-up photo of the nail(s) you found, as well as photos of the deck, so I can better evaluate the issue.  Our e-mail is: info@majordesigngroup.com

--Steve Major