Adding Electrical Wiring to a Wall With Spray Foam Insulation

A wall with spray foam.
  • 20-40 hours
  • Advanced
  • 10,000-20,000
What You'll Need
Drill equipped with spade drill bit
Drywall saw
Measuring tape
Grease pencil
Electrical wires
Insulating/electrical tape
Draw/fish tape
Electrical outlets

Spray foam insulation is generally used in most modern houses to provide protection against very hot or very cold conditions by keeping the temperature inside at a tolerable level. One downside to having spray foam insulation is that it is hard to perform any modifications, like adding new electrical wiring and outlets, once it is installed. If you do need to add some electrical wiring to a wall with an existing spray foam insulation, then you can either hire a professional or follow the steps below to do the project yourself.

Step 1 - Plan

Carefully plan before you drill to avoid unnecessary work and electrical hazards. Then, determine where you plan to place the wire ends and the sockets you are going to use. If you already have a properly laid-out plan, you can start by drawing the spots where you intend to place your sockets using the grease pencil.

Step 2 - Measure Outlet Placement

Take into consideration where you are either getting or sending out the wire that you're going to place. Use your measuring tape to determine the distance from the outlet to the intended place in the ceiling.

Step 3 - Make Holes

After making sure that the power is cut off, go to the floor on top of the ceiling wall and find the exact location of where the wire would appear. Use your drill to make a hole small enough for the wires to run through it and make sure that there are no obstructions, except the insulation, from that spot down to the socket area. Return to the wall socket area and use your drywall saw to cut the trace of your socket out from the wall.

Step 4 - Add Wiring

Using your fish tape, go back again to the place where you made your hole above, then push the wire down to the hole up to the point where it reaches the socket hole area. Retrieve the wire by going back to the socket area and drawing out the end of the fish tape. Affix the other end of the fish tape, which is the one that remained above, to your electrical wire by wrapping it together with electric tape. Then, pull the socket end from below to snake your electric wiring through the spray foam insulation in the wall.

Step 5 - Connect the Power

Fasten the electric wires to the socket, then connect the other end above to the wires that link up to your power source. Make sure both are properly done to avoid any bad or defective connections. Finally, attach the electrical outlet firmly by screwing it directly to the wall. Turn on the power and test if the outlet is working properly.