When running rough wiring along and through studs and plates, can the wires be doubled up (two wires under one staple or two wires through one hole)?
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
![](https://images.finehomebuilding.com/app/uploads/2019/07/09093552/021285034-main-thumb-16x9.jpg)
Choose the right WRB product and install it well, because if you're not keeping water out, nothing else matters.
Featured Video
Builder’s Advocate: An Interview With ViewrailHighlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
Yes
If you haven't drawn blood today, you haven't done anything.
Thank you for your reply.
In my experience, and subject to local ruling, two flat, 12/2 or 14/2, cables are generally allowed to be stapled together as long as both are flat to the wood and the staples hold well without having to be overdriven. Ideally the staple should allow either cable to slide a bit, with only a little resistance, if pulled. Flat cable should not be stapled edgeways as this tends to damage the cable structure and invite short.
Three wire cables, 12/3 or 14/3 typically, have a round profile and they shouldn't be doubled up. They also demand extra care when being stapled because where the wires cross internally pressure tends to pinch the insulation on the conductors causing a short or fault.
There are plastic retainer and bridge units that will hold multiple, some up to a dozen, cables while providing some space between the cables for ventilation. I seldom use these but they have a place.
Thank you for your reply. Is there a rule of thumb you go by when drilling plates?
Drilling plates.The only ideas that come to mind are:Generally 3/4" or 7/8 is large enough. Drill two overlapping and you can get a large range cable through. Smaller holes make it easier to fill with fire block caulk but don't go too small as you need to be able to pack sufficient amounts of caulk.Several inches out of line with the stud is good. If you drill in the middle you eat up more cable because the cables tend to be run up the side of the stud. Don't forget nail plates. Not required if you can maintain the 1-1/4" clearance but still a good idea any place nails, or screws, are likely. Especially where cabinets or other wall mounts are going. When drilling top plates don't drill through the roof sheathing. A strong drill, a long auger bit and a sticky trigger can make this an issue.Limit the number of cables in the drilled hole to what will fit easily and quickly. Usually two. Drilling another hole is faster than trying to force fit a cable.
I asked the ESA guy today (Electrical Safety Authority) the very question about the staples today. His response was if the packaging from the company who manufactured the staples says you can double staple, then you can, otherwise don't try it. As far as the holes go I generally drill 7/8 of an inch in wood or use 7/8 grommets in steel studs and they can easily accomadate 2 wires.
Have a good day.
Cliffy