Replies

1. 
   florida | Mar 29, 2018 09:15pm | #1

   Not at all unless they are in a wet area in which case you have other problems.

2. 
   DanH | Mar 30, 2018 04:41pm | #2

   I would point out that, if you're paranoid, there are PT screws which are virtually identical to DW screws and which are sufficiently short for the task of mounting drywall.

   (But, realistically, by the time DW screws have corroded away in this use, the drywall itself will have turned to mush.)

1. 
   gfretwell | Mar 31, 2018 11:14pm | #3

   I suppose it all comes down to how seriously you take the scare stories about using regular fasteners in the new PT.

   I am approaching the end of a 5 year test I am doing on it. I tried everything I could think of that you are not supposed to do. This has been sitting out in the dirt for over 4 years now. In October I am going to take it apart and assess the damage.

   View Image

1. 
   florida | Apr 02, 2018 06:56am | #6

   That's ironic! I actually didn't notice that it was you that posted the question until after I answered then wondered why you were asking since I assume you already know the answer.  I immediately remembered your fastener test and was going to ask whatever happened with it. 

   I can tell you that i just had my pool enclosure rescreened and the guy that did it insisted on replacing the original galvanized Tapcons. He says they're always rusted through and the new screen will pull them out of the concrete. I gave him SS concrete screws to use. My son's enclosure, built in 88, is coming apart at the joints due to the screws rusting away. 

1. 
   DanH | Apr 01, 2018 09:12am | #4

   Screws in grade-level concrete are a much different matter from screws in a piece of PT in a vertical (and presumably out-of-the-weather) wall.   Except in desert conditions concrete is always damp, and contains corrosive chemicals that migrate with the water, so the corrosiveness only intensifies with age.

1. 
   florida | Apr 02, 2018 07:08am | #7

    Another great danswer! Except of course as a practical matter you're totally wrong as usual, concrete is not always damp. How do you think the furring strips are held to the concret block  walls?  What is it that's used in the undergroud footers of all walls?  How are the posts on steel buildings held in place? Coastal America is covered with Civil War area forts with iron bolts still sticking out of  concrete  that was made with beach sand and that stays wet. Buildings and bridges all over the world are help together with bolts in concrete that are not corroding away.

2. 
   DanH | Apr 02, 2018 08:06am | #8

   Another great display of ignorance!  First, you ignored that I said "grade-level concrete".  Then you clearly do not understand the chemisty of portland cement -- water is a critical part of the chemistry and remains so for the life of the substance.  Concrete will absorb moisture from the air if it must, to maintain its integrity.

3. 
   florida | Apr 02, 2018 02:25pm | #9

   And all those things I mentioned are at grade level or below aren't they? By you definition they are all in damp concrete except of course they aren't. Come on Dan, you're always cagey about your construction experience, tell us all how many yards of old,  wet concrete you've demoed.  My bona fides are at the bottom of all my posts, lets see yours.

4. 
   DanH | Apr 02, 2018 04:20pm | #10

   Grade level -- flat on the ground.

5. 
   florida | Apr 03, 2018 11:01am | #11

   Bingo! Another danswer! You win!

6. 
   gfretwell | Apr 03, 2018 08:26pm | #12

   Guys I did start this note saying "coastal construction" and that pretty much says the 1st floor will be 14 feet above the datum plane. There won't be any furring or drywall anywhere near the ground.

   That still does not mean the concrete will not be moist. Near the beach, humidity runs around 100% at night and if the air is not on, water can condense inside. I would not be surprised if this wood has a very high moistore content.  In fact the only wood I see here is the door jacks, window bucks and the furring strips. Everything else is metal frame until you hit the roof trusses.

7. 
   Mike_Mahan | Apr 04, 2018 04:43am | #13

   Steel for furring.

   Why not use steel studs or channel for furring? 

8. 
   junkhound | Apr 04, 2018 10:07am | #14

   Speaking of Piffin screws,  Paul hissownself is back over at BT3. 

2. 
   gfretwell | Apr 01, 2018 02:16pm | #5

   I am still waiting on my test. It has been undisturbed fior 5 years, much as something would be in service. The question was prompted when I was looking at some new construction at the beach. They are even using the PT on the 3d floor. I assume they think something will get wet, by humidity, spray or surge although if it is 30' high, I doubt the drywall screws will be their biggest problem. 

1. 
   florida | Apr 05, 2018 08:44pm | #15

   Where are you seeing the steel framing? In new houses? Wouldn't it stand to reason that if the screws will rust so will the studs?

   I've used nothing but PT lumber for anything even slightly exposed to weather at the beach and Sanibel for 40 years without any problems. Again, don't remember ever seeing a rusty drywall screw except around some sort of leak.