Insulation

It’s that time of year to think about ways to keep the heat in and the cold out! Besides tightly closing all your windows and making sure your weather-stripping is in good shape around your doors, it’s a good idea to be sure you’ve got the proper amount of insulation in your home.

There are many different dimensions of insulation depending on the cavities being filled. There is insulation for framing that is 16” on center and 24” on center. There is insulation that is 3 1/2” thick for walls and up to 8” thick for ceilings and floors. Insulation is also referred to by its’ R-value. Simply put, the R-value refers to the materials’ resistance to heat flow. The greater the R-value, the greater the insulation ability. You can get 3 1/2” insulation with 3 different R-values, R-11, R-13 and R-15, so be sure to ask your supplier what’s available.

The insulation process is certainly not the most desirable, particularly crawl spaces and attics. However, the proper clothing and equipment makes the job a lot easier. And when you get your next heating and/or cooling bill, you’ll see it was well worth the effort.

Let’s start with the crawl space. I would use a minimum, R-19 in this application, with a foil face. The foil acts as a vapor barrier and the vapor barrier, regardless of the location, always faces the heated space! So, in this case the foil would go up and the insulation is held in place with pieces of rigid wire which are pre-cut and available from your supplier. You simply bend them in place between the joists. You want to be careful not to overstuff the insulation anywhere. When you come to a cavity that is less than 16”, you’ll need to cut it accordingly. Using a utility knife, lay the insulation foil side down, pushing down on it with one hand, cut it with the other. I usually cut it about an inch wider and longer than the actual measurement. You also want to be sure not to block any vents or to conceal valves or electrical boxes you might need access to.

In the attic, I recommend at least an R-19 also in the floor beams, remember, the vapor barrier would be facing the ceiling! If you have insulation in the attic now with a vapor barrier and would like to add some more, you must use an, “unfaced” insulation. If you double your vapor barrier you’ll be trapping moisture and you don’t want to do that. You want to be careful not to cover any vents in the attic either.

If you’re going to be finishing your attic, you’ll want to insulate the rafters first. In this application, you’ll need to use an R-30 insulation as well as provide an air space behind it. Your rafters need to be 10 “ deep, which is unusual for a rafter. What you’ll probably need to do is to build them up by nailing strips of wood to the bottom in order to make them 10”. To maintain an air space, you can purchase styrofoam that is designed for this purpose which fits between the rafters and is molded to leave about an inch of space for air to flow. You only need to do this in the part of the rafter that is going to be finished. In the horizontal portion of the ceiling, you can use an R-19 again. If there is no horizontal portion, you’ll need to have a ridge vent cut into your roof. (Check with your supplier).

To install the insulation between the rafters or in the horizontal ceiling, the vapor barrier faces the room and has flanges that open up for you to staple through. A staple hammer is the easiest tool to use for this application. You’ll need to staple about every 16” on each side. Be careful not to rip the vapor barrier.

If you have no insulation in your prefinished walls, I recommend blown in insulation. Just be sure the entire cavities get filled. If there is a horizontal member in the wall, the insulation will not fill the entire cavity without drilling another hole. (I would leave this to a professional).

A word of caution, don’t ever install insulation around hi-hat type lighting. If you have any question, please check with a professional about that. And, as an effective way to minimize the insulation getting into your skin, put a liberal amount of powder on before you cover everything up. Please, where gloves, long sleeves and make sure you use a respirator.

Another real good way to keep your home warm is to put a cherry pie in the oven!
 

Estimated time: Depends on the location, but it’s time well spent!

Tools/materials needed:

Utility knife, staple gun or hammer, staples, wire stays, respirator, insulation talcum powder & gloves.

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