jeremysterling
Senior Member
- Location
- Austin, TX
Placing decking in attic
- Thread starter james_mcquade
- Start date
- Status
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
If you have an 11' span with 2x6 joists then you have a problem. If the ceiling joist is part of a truss then I am not sure they should be drilled. What depth insulation do you have in the attic. Around here you need R-30 so that is 9-10" of insulation. I would fur the joists with 2x4 and then notch where the wires run. I would then get more insulation and then screw down the plywood.
But why give yourself (2) possible failure points if you can avoid it?
jeremysterling
Senior Member
- Location
- Austin, TX
I do mostly service work, so adding boxes and splices is pretty routine for me. Sometimes its 200 amp conductors with compression butt-splices and cold shrink in a 12" trough. Other times its red wire nuts in a four square box. I never consider these joints "possible failure points."
Even at NASA's Johnson Space Center, where "failure is not an option", I routinely set boxes and made joints with wire nuts.
And avoiding twenty foot of 14/2 romex, (2) plastic boxes and (6) tan wire nuts is possible. Just walk around with a flashlight.
jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
Would you Home Run every outlet? Run multiple switch legs?
No I don't homerun every outlet or switch leg. But IMO it is better to have less points of failure. I have yet to repair a splices that i have made. When i make a splice i make sure it will last a very very long time. But if there is another solution for the OP then i think he is better off with furring strips. Just my 2 cents.
readydave8
re member
- Location
- Clarkesville, Georgia
- Occupation
- electrician
Like edward I'm not worried about my splices and don't mind using junction box where necessary, however avoiding junction box sometimes makes things simpler.
kwired
Electron manager
- Location
- NE Nebraska
As a couple have at least partly covered, just what exactly is the joist to be bored, notched, etc. If it is part of a truss it is possible it should not be bored or cut at all as that may effect the strength of the entire truss. They can make a large framing member out of pretty light material but about every bit of the material making up the truss is critical to its performance.
jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
Trusses may not be 'tampered' with in any way. There is a 'left' and 'right' side to a truss even if it looks the same, symmetrical. Pick up a truss drawing (required to be on site during construction) next time that you do a resy project.
james_mcquade
Senior Member
Thanks everyone for the replies.
the offending wire is located above a hallway that is 5 ft wide running diagonally about 10 ft.
i removed some items left by the previous owner and found wiring with decking layed on top of the wires !
i removed the decking and inspected the wiring. no apparant damage.
i have since removed that decking and sawed the decking to free the wire, no notches or boring. the wire is out in the open and exposed for all to see.
i am still working on the problem with the hall way. the wiring is #14 for a 3 way light.
if i bored a hole it was going to be 3/4"
no notches or boring was to be done over the rooms.
thanks again,
james
the offending wire is located above a hallway that is 5 ft wide running diagonally about 10 ft.
i removed some items left by the previous owner and found wiring with decking layed on top of the wires !
i removed the decking and inspected the wiring. no apparant damage.
i have since removed that decking and sawed the decking to free the wire, no notches or boring. the wire is out in the open and exposed for all to see.
i am still working on the problem with the hall way. the wiring is #14 for a 3 way light.
if i bored a hole it was going to be 3/4"
no notches or boring was to be done over the rooms.
thanks again,
james
kwired
Electron manager
- Location
- NE Nebraska
I realize you are over a 5 ft wide hallway, but is the joist in question part of a much larger truss? If so that truss is depending on the integrity of all the components making it up for its strength. Drilling the bottom chord may not hurt it as far as vertical stresses since it is a short span to hallway walls that will help support it, but very well may weaken it for horizontal stress imposed on it. The weight of the roof will be placing some horizontal force on the bottom chord.
- Occupation
- Licensed Electrician
I just don't see any reason to avoid j-boxes other than the time it takes to mount it and make up the splices. If the pay off is worth more than the effort, and we agree that good junctions don't fail; where is the downside?
A/A Fuel GTX
Senior Member
- Location
- WI & AZ
- Occupation
- Electrician
I'm assumimg you are referring to trusses and not joists. I don't believe it's legal to bore holes anywhere in a truss.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Here is a good reference
A/A Fuel GTX
Senior Member
- Location
- WI & AZ
- Occupation
- Electrician
Great graphic, Dennis. Notice trusses are not part of it? I believe the OP's situation is in violation of code with holes bored into trusses.Here is a good reference
kwired
Electron manager
- Location
- NE Nebraska
Any engineered framing member may have different rules as to cutting and boring.
We don't know for certain if the OP has trusses, but we have concluded it is a good possibility.
renosteinke
Senior Member
- Location
- NE Arkansas
Dennis, I think your reply is pointing the OP in the wrong direction.
First off, the graffic is for certain framing members made of dimensional lumber. Glulams and TJI's have different rules for hole making.
Second, the atrwork does not include 'engineered trusses.'
By far the most common form of roof framing, these trusses are designed with the absolute minimum amount of wood. Even simply placing decking in your attic and storing stuff can be a risky proposition; many have found this out the hard way when they attached hoists to their garage trusses.
Such trusses are not allowed to be drilled or notched at all.
First off, the graffic is for certain framing members made of dimensional lumber. Glulams and TJI's have different rules for hole making.
Second, the atrwork does not include 'engineered trusses.'
By far the most common form of roof framing, these trusses are designed with the absolute minimum amount of wood. Even simply placing decking in your attic and storing stuff can be a risky proposition; many have found this out the hard way when they attached hoists to their garage trusses.
Such trusses are not allowed to be drilled or notched at all.
jxofaltrds
Inspector Mike®
- Location
- Mike P. Columbus Ohio
- Occupation
- ESI, PI, RBO
disagree. OP said joists so trusses are not what is being discussed.
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