# Filling old screw holes when replacing deck boards



## Matt_D (Feb 14, 2012)

Hello,

I am in the middle of a project to replace the pressure treated deck boards on the deck behind my house. The joists under the decking are still in relatively good shape so I'm planning to reuse them. The problem I have is that after removing the deck boards I am left with a bunch of screw holes in the joists. I'm worried that water will collect in these holes and accelerate the deterioration of the wood.

Before installing the new deck boards should I fill these woods with something to plug them up? If so, what type of wood filler would hold up to an outdoor environment like this?

Thanks for the help,
Matt


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## Dal300 (Aug 4, 2011)

Pressure treated wood shrinks and swells with the weather. I wouldn't worry about filling the holes.

As an addendum, I would take up the worst looking joist and cut it apart in many places to see how bad it really is. This is just for piece of mind. I rebuilt a deck awhile back for a friend and all the joists looked good until I started putting screws in. Three of the joists were of inferior grade SYP cut from the core and even using 5" deck screws I couldn't get them to grab. I ended up cutting them out and replacing them.


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## Doss (Mar 14, 2012)

Grabbing some roofing paper and cover each joist if you're that worried about it. Another option is getting out the caulking gun and filling each hole with a dab of silicon.

I'd only do this if the new decking wasn't going to cover the holes.


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## SWM (Jan 10, 2010)

Great question. This is one of those things that I would think about too. My guess is it probably doesn't matter, but if you are like me, you might lose sleep a couple of nights worrying about the "best" way to rebuild that deck. I just happened to read this artlcle over the weekend and I'm seriously considering adding to my next deck rebuild this summer. Hope this helps and let me know how it goes.

http://community.familyhandyman.com/tfh_group/b/diy_advice_blog/archive/2011/02/23/protect-your-deck-from-joist-rot.aspx


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## MrRon (Jul 9, 2009)

You could slather on a coat of tar on the top of the joists.


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## doughan (Apr 22, 2011)

Any thing you put over the joist that will slow the drying between rain storms only accelerates the rot process.Tar and tar paper won't do any good at all

use something that will penetrate the joists and repell water from ever getting into the interior of the wood.


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## Doss (Mar 14, 2012)

Two details I forgot to ask (and I think everyone else has too) is where you are located and how much rain is this deck going to get?

Help us help you.


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## Maggiepic (Aug 26, 2010)

Don't worry about filling the holes, cover them up as mentioned earlier by Doss. A step better would to use ice and waterguard, even better would be a self adhesive membrane for flashing windows. All your new fasteners would self seal in the membrane to prevent any future water intrusions. Whatever you use, saddle it over the joist.


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## donwilwol (May 16, 2011)

I second what Dallas wrote. Won't the new deck boards cover most of the holes anyhow?


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## Matt_D (Feb 14, 2012)

I am in northern Illinois so the deck will be getting plenty of rain and snow. It sounds like the holes won't be such a big deal so I may just leave them.

Matt


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## ChuckC (May 13, 2010)

You probably don't have to do anything but you could always put the screw back in the hole, under the new deck boards and flush with the top of the joist.


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