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How close from joist hanger is it ok to drill a hole?

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covfefe

Civil/Environmental
Apr 21, 2022
4
I can't find any guidelines on this. How close from a joist hanger is it ok to drill a hole? Or is it irrelevant?
(joists are 2x12, hole 3.5")

The answer I'd like is anywhere between 1-5" ha.

IMG_0245_uf1lit.jpg
 
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I'm not aware of a general rule for the location of a hole relative to the distance from supports for sawn lumber - just location vertically. I'd have to consider the whole situation. At first glance that looks too close to the end, though, especially if you're going through more than one joist.
 
Probably "d" from the end of the beam would be a safe starting point.
 
I'd want to be at least 1.5 joist depths away from the hanger unless I could prove that the thing was viable assuming only this was left:

c01_orlc91.png
 
My annotations could have been clearer. I have updated the picture in the post to add some details.

The 3.5" hole will be about 1/3 through the joist, so nowhere near the ends of the joists.
 
Most firms' typical detail will say something like "penetrations allowed within the middle third of the depth and the middle third of the span with the following limits..."
 
@KootK, yes. The 3rd rules work just fine here: 3.5"/12" = 29% < 1/3 and we are located around 6ft/18ft = 1/3 of the joist length.

My only worry is the nearby joist hanger. Ideally, I'd drill it as close as possible to the hanger (1" or so. But it feels like there has to be a minimum clearance rule somewhere...)
 
If you drill it an inch or so from the joist hanger, the hole is not in the middle third of the joist span.

BA
 
BA - I think the joist being holed is the supporting member.
 
phamENG said:
BA - I think the joist being holed is the supporting member.

Of course! That makes sense. Why didn't I see that? My grand-kids would say "old and slow".
A distance 'd' away from hanger would be desirable, but it probably is not critical.

BA
 
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