Code Allowance for Holes in Joists Bob K

Bob, 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?

T
Reply to
tbasc
Loading thread data ...

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 joists! ;)

R
Reply to
RicodJour

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 great idea.

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 the hole.

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 up.

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.

cheers Bob

Reply to
Bobk207

Does this apply to end notches on the top edge as well? Perhaps you could comment on my "Joist Selection" thread. :-)

Cheers, Wayne

Reply to
Wayne Whitney

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.