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Most of the work I do is additions and alterations in domestic properties, and other than swapping accessories and lights in new-builds for fancier ones, the majority of the work is in older, "traditional build" houses. I've come across a range of interesting construction methods, including walls made of straw and Wimpy no-fines - every day's a school day. I've tended to steer clear of bigger jobs on newer builds, particularly those with engineered I-joists (JJI/TJI/FJI) as I'm burdened with a risk-averse nature and I don't know much about them and don't want to start drilling holes in things I don't understand, but I'm wondering if this abundance of over-caution is justified or not?
I've found a couple of manufacturer's spec sheets that say you can drill holes up to 20mm pretty much anywhere in the web, which would cover >95% of all the jobs I'd need to do. Obviously don't damage the flange. And they seem to be able to accommodate much larger holes if done in the right places, much bigger than would be allowed on a solid timber joist. I've seen holes for 110mm soil pipes in the local Barratt houses they're chucking up nearby, but for all I know they might be supplied pre-fabricated that way for that size of project.
So what's the general deal, those of you who come across these more often than I do (new builds etc)? Is there a massive variation in what's permitted between different manufacturers, or are they all pretty much the same, i.e. if you keep the hole small (≤20mm) and in the middle (top to bottom) of the web, then you're pretty much ok? Or is my fear of drilling holes in new-fangled things justified?
Cheers!
I've found a couple of manufacturer's spec sheets that say you can drill holes up to 20mm pretty much anywhere in the web, which would cover >95% of all the jobs I'd need to do. Obviously don't damage the flange. And they seem to be able to accommodate much larger holes if done in the right places, much bigger than would be allowed on a solid timber joist. I've seen holes for 110mm soil pipes in the local Barratt houses they're chucking up nearby, but for all I know they might be supplied pre-fabricated that way for that size of project.
So what's the general deal, those of you who come across these more often than I do (new builds etc)? Is there a massive variation in what's permitted between different manufacturers, or are they all pretty much the same, i.e. if you keep the hole small (≤20mm) and in the middle (top to bottom) of the web, then you're pretty much ok? Or is my fear of drilling holes in new-fangled things justified?
Cheers!
