The bigger question is whether it is permissible to make holes at all, or if so, where in the I-beam, and how big?
I presume you are talking about making holes in the web of the beam. If holes are required and are permissible, it is usually best to have them punched in the shop when the steel is fabricated. In the field, holes may be cut with a torch, but not without the approval of a structural engineer or competent architect.
Probably, holes cannot be cut at all in the outer thirds of the beam, without also reinforcing the web where the hole is cut, but the specific holes should be approved by a design professional wherever they are to be cut, and then they should be cut by a licensed welder.
Architect (NY) and Home Designer (PA)
Posts: 2450 | Location: Tobyhanna, PA | Registered: 24 October 2005
Thank you Richard for your insight. I will pass your suggestions on to the manufacture.
Richard I had a chance to speak to several structural engineers who said that putting small holes in I-beams to run electrical and plumbing will not affect the structural strength of an I-beam. They also said that if what you were saying was true then builders would need to consult and architect or engineer every time a wood frame home was constructed, because wood has ten times less strength than steel. Plumber and electrician drill holes in wood exterior wall studs and interior floor joists every day. Richard I thank you for your post.
This message has been edited. Last edited by: Trysteelfla,
Posts: 3 | Location: trysteel@trysteelfla.com | Registered: 27 July 2007
You use a drill. If you need a larger hole you use a step drill. Look in the electrical tool section at your favorite hardware store.
The rules are simple only drill in the center of the web of the I beam. Most of the stress is in the top and bottom. You should use a pvc electrical condut fitting to protect the wires from the steel
The engineers were being silly. When a hole is cut in a steel beam by a torch, it has uneven sides and produces stress points in the perimeter of the hole. Also, if the welder isn't careful, he can overheat part of the beam, and substantially weaken the beam. Finally, there are places where holes are permissible, and places where holes are forbidden, and there are limits as to the size of the hole in each place. Very large holes may require that the beam be reinforced. A steel beam in a residence is usually a girder carrying enormous load. That is very different from a single joist or two in wood framing. I've seen parts of wood joists cut out entirely, and somehow the structure stood. That would never happen with a steel beam. Tell those engineers they need sone continuing education.
Architect (NY) and Home Designer (PA)
Posts: 2450 | Location: Tobyhanna, PA | Registered: 24 October 2005