While there may be debate between individual contractors about spraying foam insulation over electrical wires, industry guidelines state that spray foam insulation can be applied directly over electrical wiring. The fact is, when wiring is properly sized and housed, there should not be any temperature issues as a direct result of the spray foam. As for applying spray foam to seal up recessed lighting fixtures (or other fixtures), this may necessitate some air circulation to ensure cooling. There are a number of construction options that will accommodate this.
In terms of ensuring accessibility to electrical outlets, junction boxes, and lighting fixtures, it’s a good idea to plan it out ahead of time, well before the spray foam insulation is even applied. For a good insulation contractor, this is academic, because it becomes part of the overall project, and planned accordingly. In fact, in some cases, empty electrical conduits can be installed (for future use) and easily covered with spray foam. In this way, an electrician can use the hidden conduits to route wiring without having to break open the already installed spray foam.
Another aspect of spray foam insulation, with respect to electrical wiring, is its capacity to block moisture – a definite advantage with electricity. As it is, industry groups have conducted several decades of extensive testing, finding that spray foam insulation does not affect electrical wiring when safely applied and installed. Importantly, old “knob and tube” wiring cannot be covered over with spray foam insulation. Here, a professional insulation contractor will recommend the removal and re-installation, with upgraded, building-code-rated wiring.
Spray foam insulation is not corrosive to metal. When spraying on or around existing wiring, the gauge/voltage of the wiring should be taken into consideration. There are, however, concerns with wiring that is low-voltage. For the most part, experienced contractors will avoid spraying this type of wiring, and in any situation, will choose to be safe rather than sorry. Most attic insulation products are installed over and around electrical wiring, and spray foam is no exception. The key, of course, is a professional installation, so that potential overheating of electrical wires is totally prevented. This is definitely not the appropriate time for a do-it-yourself installation.
At Great Northern Insulation, specializing in spray foam is about having a team of experts with years of product experience and installation expertise. Install teams always work according to recognized industry standards, and follow all applicable building codes. It means that electrical wiring, HVAC ductwork, and interior plumbing is handled with care. As well, GNI installers don’t take shortcuts, and work to the manufacturer specifications. This expert approach to installation provides the homeowner with the assurance that everything is safe.
GNI installation teams are licensed and certified with spray foam products. They prepare the job site the right way; they use appropriate protective gear and safety equipment; and they make certain that residents and occupants are safe during the installation process. In the attic, roof, basement, or garage, spray foam can deliver excellent results, but it’s an insulation product that must be expertly installed and professionally managed.