Feeling your walls is an easy indoor project for a cold winter evening. Take a tour of you place and feel the walls in each room with your bare hand. Take notes or make a sketch of the floor plan. Mark the coldest spots that you discover.
You are not checking for the actual temperature of the walls. You just want to find out which walls are colder than the rest. You also want a reminder of where they are so you can fix the problem later on.
If you prefer to find out exactly how cold your walls are, I recommend the pistol grip style of infrared thermometer that are available now. I often use on in my day job as an Energy Conservation Engineer.
It is logical that the inside surface of the exterior walls will be cooler than the interior walls. It is normal for the walls next to the windows to be cooler than the wall between the kitchen and bathroom for example. You may be surprised to find that one wall is colder than the rest.
Remember Your Walls Are Hollow; See the Photograph
The empty space inside of the walls of your house makes a pathway for air to flow up or down. Typically, warm air from inside your house will sneak up to the attic using the secret passageways inside the walls. Hollow walls waste energy when they act as an escape route for air that you paid to heat.
Hollow walls can also provide a pathway for cold air to drop down from the attic making the wall feel cold.
Seal Off the Secret Energy Passageways In Your Walls
A can of spray foam insulation is the modern answer for shutting off the energy escape route in your walls. Use the foam to seal the wall at the floor and in the attic at the top of the wall.
WARNING: Don’t go crawling around in your attic unless you know how to avoid putting you foot through the ceiling or worse.
WARNING: Use just enough foam to do the job. Excess foam can cause damage as it expands.
All holes for wires or pipes need to be sealed in the attic. You need to seal around ductwork that goes up into or down from the attic.
A small amount of spray foam can be used to seal electric outlets. Take the out let cover off and squirt a little foam into the wall at both sides of the outlet. Trim off any excess and put the cover back on.
You can seal light switches the same way. Spray foam is fun to work with.
What to Do About Cold Exterior Walls
Cold areas on exterior walls indicate that there is air moving inside the wall or that there is not enough insulation inside the wall or both. Map out the cold spots and then talk with an insulation contractor about having spray foam injected into the walls. Spray foam seals and insulates, all in one application, fixing both types of cold wall problems.
The job needs to be done by a contractor who has the equipment and knowledge of just how much to use without damaging your walls.
If too little foam is used the wall will still have hollow areas.
If too much foam is used it will push out so hard, as it expands, that it can split the wall open. Fixing bulging walls will be expensive.
Eliminating cold walls will reduce your heating bills and lower your air conditions bills too. You will be more comfortable and save money.