H Beams.

How big a hole?  (I have drilled a hole through a ship's side before now.)

That's a wide question!

The thing is, what for?

Some H-beams have holes drilled in the web (for lightening?). The ½ ton beam across my garage has some small holes in it and it has sat there for nearly 90 years. I have even drilled a hole in one to get a cable through. Neither beam has collapsed.

You can drill holes in wooden joists.

Not at all scientific (in an engineering way), but my final answer is “yes”.

AncientMariner: 
How big a hole?  (I have drilled a hole through a ship's side before now.)

Presumably above the water-line. ??

This type of building……..

AncientMariner: 
 

How big a hole?  (I have drilled a hole through a ship's side before now.)

Any size hole in the load bearing H beams.

Z.

Looks like a nice garage! ?

I may well enroll in an Open University engineering course this year, partly because I think that it would be useful to know about simple beams.

So let's say that you drill a 20 mm hole in the web. If it were going to fail, presumably the hole would squash in from the sides. But if you put some galvanized conduit through, the picture may be very different.

Oh well, make sure that your insurance is paid up and give it a go!

I would be very reluctant to drill any holes in the beams of a modern building such as that illustrated.  I suspect that modern buildings are designed “close to the limit” with very little safety margin. 

Several have collapsed unexpectedly.

I suspect that modern buildings are designed “close to the limit” with very little safety margin. 

About 20 years ago I understand that some large span agricultural use ones collapsed under the “allowed for” snow loading and it was ascertained that it was due to the bolt holes being punched out, so it became a requirement for the holes to be drilled.

Not sure if it is still a requirement………………………………………………

As to the OP, good luck in getting a committed answer from the supplier…………………

Regards

BOD

?   We were always lead to believe that you never drilled holes of any size through RSJs where they providing engineering structural support. You were supposed to use conduit and pipe hangers.

If unsure what I'm talking about then check out amazon or ebay …… lol

Legh

ps. mind you, I've seen what happens to RSJs when consumed by fire. They warp and buckle and collapse in a tangled mess……

Where  I served my time you had to get written permission from the works engineer to drill beams