English Deutsch Français Italiano Español Português 繁體中文 Bahasa Indonesia Tiếng Việt ภาษาไทย
All categories

3 answers

Check with your local building inspector

local codes vary

2007-01-11 04:12:32 · answer #1 · answered by Anonymous · 0 0

I wouldn't make that assumption without qualified inspection. But I have limited knowledge of the private market, I usually do civil.
Safety factors are included, and many builders intrinsically know the size/loading factors without math, knowing they will need cable access. So it could well be a reasonable assumption. However the official inspection will be a problem without the plans. Safety wise it's too risky without knowing for sure, for your case.
And 2 inches is a hell of a lot for any joist not made from re-inforced concrete. Joist are comparably expensive, and I never design a structure with anything near that much overdesign (my boss would kill me, after the accounts department gave him an earful).
If the joist are steel, cutting through the top or bottom flanges is a no-no. Just to cover my ****

2007-01-11 03:11:39 · answer #2 · answered by Simon D 5 · 0 0

50mm sounds too much.

The least stressful part of a beam is in the middle. If you can you should drill through the beam and run pipes and cables trough the middle.

generally I would chisel only 25 mm into a roof joist.

and of course that assumes that it was built properly in the first place. Some older roofs are very thin compares to modern regs. If you have a typical span of 4 metres with a 6x2 or less then you can't touch them. The roof joists need to be 200mm min for a 25mm cut

2007-01-11 02:59:55 · answer #3 · answered by Michael H 7 · 0 1

fedest.com, questions and answers