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Removed some drywall next to the garage door opening and found a couple of large holes in the OSB.

Water main enters the wall on the other side of the lower hole and it looks like some water pipes were replaced at some point.

I’m trying to avoid bringing the garage door brackets into play, so would it be safe to cut out this 2-foot section of OSB and replace it? Unsure of any potential structural ramifications…

Or should I instead repair/cover the holes to better cover the water pipes?

Or … should I just leave it as-is and put up new drywall?

garage wall OSB with holes

EDIT: Adding info and pics to address questions below.

  • I don’t see nails or screws attaching the OSB to the studs. There are staples in the OSB going into the left-most stud in my picture above. There are no fasteners going into the next stud, which is 16” oc from the first. Since I only opened 2’ of drywall, this is all I can see.
  • The staples are roughly 4” apart starting from the top, but they get sparse on the bottom half of the OSB, until there are only two remaining that are about 15” apart. Perhaps a couple were missed (?)

Staples fastening OSB to stud

  • The top hole in the OSB had some of the cut piece sitting in the cavity attached to a 1x2. The 1x2 was just sort of floating. Perhaps I can use this piece to make a better patch, though the top would still have a small strip opening based on how it’s cut:

Cut piece from top hole

  • The bottom hole is cut much less neatly, let’s say, and feels a bit trickier to patch well — there’s no remaining piece from that cut, unless it was dropped into the wall cavity with the rest of this stuff that I haven’t cleaned out yet:

Bittom hole in OSB

My motivation for removing the drywall in the first place was: I’m insulating the garage and will eventually be cooling it to use as a shop in the hot summer months here in Southern Arizona. I’m also trying to seal up some rather large cracks and access points for the many large insects that come and go as they please. I know I can’t keep them out completely, but I hope to make it less easy for them in general. So sealing and insulating is where I began, and I’m also fixing issues as I find them.

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    What's the spacing of the screws attaching the OSB to the studs?
    – popham
    Commented Oct 25, 2023 at 22:23
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    I’m seeing staples, not screws or nails, attaching the OSB to the left-most stud. I’m not seeing any fasteners on the OSB along the next stud to the right, which is 16” oc.
    – R.J.
    Commented Oct 26, 2023 at 16:08
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    For the 4" spacing of staples, my suspicion is that this is non-structural. I could see using the staples to position sheets, where you come back later to nail them on a fastener schedule. 4" spacing is way too tight for somebody implementing this pattern. I don't like this sort of inferential bumbling, though, so I might still treat it as structural. I would definitely ridicule myself as I did it.
    – popham
    Commented Oct 26, 2023 at 16:45
  • @R.J., thanks for following up, but resolutions don't belong in question posts. There's also no need to denote edits. It's all in the log anyway. Go ahead and post an answer if you like.
    – isherwood
    Commented Nov 27, 2023 at 17:42

2 Answers 2

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That's a common location for wall bracing, where if it's bracing, then the OSB strengthens the garage front against left to right (and right to left) forces. The house layout is necessary information (among many other necessary pieces of information) to say for sure. See IRC R602.10 if you want more details about wall bracing.

Why wasn't the wall framing left bare like everywhere else? The use of OSB there in contrast to the neighboring wall is a red flag, suggesting that it's structural. Alternatively to the structural possibility, though, it could be there to protect the utilities from physical damage. OSB wall bracing calls for fasteners installed every 6" around the perimeter and every 12" in the interior (see IRC Table R602.3(3)), so if your OSB has far, far fewer fasteners than that, then this signals that the OSB was slapped up by somebody looking to protect the utilities. Or your house's contractor had poor quality control.

To play it safe, I would border the hole edges inside the wall cavity with flat-oriented 2x4s, where I would then patch the hole with the same thickness of OSB. I would hold these 2x4's in position with screws and then install pairs of 6d common nails (one on each side of the seam) spaced every 6" based on IRC Table R602.3(3).

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  • In earthquake country, it’s 3” spacing on the perimeter and 12” spacing in the field. Nails, not screws. More: jlconline.com/how-to/framing/shear-walls-the-basics_o Commented Oct 26, 2023 at 14:16
  • Thanks, I’m editing the question to include some additional information.
    – R.J.
    Commented Oct 26, 2023 at 16:30
  • @Aloysius Defenestrate, under the IRC's tables, the fastening schedule stays fixed and the bracing length increases with seismicity (see codes.iccsafe.org/content/IRC2018/…). This is intuitive in that for such tables you would want to present minimum brace lengths that develop the full strength of the chosen sheathing. In your article, an engineer has diverged from the IRC in deciding a fastener schedule.
    – popham
    Commented Oct 26, 2023 at 16:35
  • @popham — noted, and somewhat moot as I don’t think AZ is seismically active. I’ll leave my link, as it represents (for better or worse) the way things are done in my seismic zone. Commented Oct 26, 2023 at 17:04
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I'd suggest screwing some nice neat pieces of plywood over the holes, and drywall around them (or trim around them and drywall around the trim) so you have access holes without bashing drywall the NEXT time the waterline needs to be accessed.

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  • DV: if this is shear (which my intuition says it is), a patch has to span studs (plural). Commented Oct 26, 2023 at 14:10
  • Lacking confirmation from the OP on the nail spacing, what I can make out in the picture looks much wider.
    – Ecnerwal
    Commented Oct 26, 2023 at 15:19
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    I see staples attaching the OSB on the left side. Some of them are roughly 4” apart, but toward the bottom there are only a couple, and they’re about 15” apart.
    – R.J.
    Commented Oct 26, 2023 at 16:10

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