Electrical Wiring & SIPs
Written by Dave Stevenson
Follow Dave on twitter: @DStevensonSIP
There’s no getting around the fact that electricians don’t like SIPs, but the reality is that SIPs aren’t any more difficult to wire than any other type of construction – just different.
If you’ve never worked with SIPs, contact an Insulspan representative before the panels even arrive and ask for your very own set of plans. If you take the time to strategize beforehand, the time spent on site will be significantly reduced. Clearly marked on the drawings, you will see a grid work of hatched lines, both horizontal and vertical, marked W.C (wire chase), that indicate every chase location within the exterior shell of the building. Trust the drawings.
All of the wiring can be run within these 1 ½” diameter chase-ways, and as long as the installers have remembered to drill similar diameter holes down through the bottom plates corresponding with the vertical chases in the panels, the wiring should be a breeze. The electrician can simply use a hole saw (any diameter is fine) to cut out a ‘plug’ at any vertical and horizontal junction. Then just use a ‘fish tape’ to pull the wire up from the floor. At that point, the electrician can either decide to wire in the outlet and run back down into the floor and then over to the next vertical chase, or run the wire horizontally through the chase over to the next junction or outlet.
The horizontal chases are completely unobstructed, which means that an electrician could install an outlet on one end of a wall and run the wire horizontally all the way to the other end without having to drill a single stud. This process would literally take only minutes. Once inside the wall, the wire can be run horizontally and vertically. If enough forethought has been put into the design, it is conceivable that an outlet or fixture could be located virtually anywhere along the plane of the wall or roof. The boxes that are typically used with SIP construction are standard ‘renovation boxes’ or sealed ‘flanged’ boxes that are fastened to the face of the OSB sheathing. These boxes are available at any building supply store.
If all this still sounds like too much, there are other options. For example, many architects, builders and homeowners are attracted to the panels because of their energy saving qualities, such as greater R-values and reduced air leakage. For this reason, they are reluctant to introduce any chase-ways what-so-ever to the exterior building envelope, and are compulsive in their efforts to eliminate all electrical wiring from the exterior shell by either moving everything into partition walls or furring out the inside surface of the SIP wall with 2 x 4s.
The point is, the electrician need not be overly intimidated by the panels. There is a way to run the wiring within the panels. It may be slightly different from conventional methods, but once an electrician has a few under his belt, he may even find panels easier and less time consuming than ‘normal’ 2x construction. For more information on wiring SIP panels I recommend YouTube. Simply enter in ‘SIP Wiring’ (or anything to that effect) and everything you need to know about this subject (with video) is right at your finger tips.