Could you expand on this comment, please?
"personally I think some code allowances for holes in joist are a
little too generous."
From your comments, you appear to have run tests.
Were the results recorded and conclusions drawn?
From that particular snippet it's unclear whether he means that code
allows the holes to be too big, or if it should allow them to be
bigger. I'm old school - if you want holes in your joists, use truss
To clarify..... some codes (I did a little researching when the topic
came up another time a while back) allow holes that are (IMO) too
large & too close together but its just my opinion
It's been a while since I looked at them but it seems that allowed
drilling & notching of joists varies a lot from place to place
I recall that one jurisdiction allowed something like multiple 2"
hole in a full size (6") 2x6, the separation required was something
like only 1" of meat between the holes! .....That didn't seem all
that large & the required separation was independent of the hole size
which didn't make me feel any better.
Some jurisdictions allowed notches, which is something I would never
do without some sort of reinforcement plan.
Sawn lumber isn't a homogeneous material & putting multiple rather
large holes in it at questionably close separation doesn't seem like a
The recent thread about a 2" hole (rather near the end of the joist)
in a 8.6" (?) deep joist didn't seem like a big deal......that's
pretty much why Robert Allison & I said "don't worry" since that was
a pretty big timber & it left a lot more than 2" of meat above & below
I've be lucky to have had many opportunities to perform & observe
tests on timber structures & components.
Often if we had a question about how something would perform...we'd
just build it & test it.
I have not specially investigated holes in joist but I'm sure
research / testing has been done on the topic.and it could be dredged
So unfortunately I don't have any hard data to share
I've seen a lot members hacked up (notches & holes; too large, wrongly
placed) so I'm not a huge fan of letting the misinformed loose with
Hole-Hawgs & Sawzalls.
Hopefully I have enough engineering sense & experience to be able to
tell when a hole in a joist is ok & when it isn't.
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