How To Add Crawlspace Insulation How To Add Crawlspace Insulation

Having adequate crawlspace insulation is essential to keep heat or cold from escaping your home. A crawlspace with poor insulation will also breed mold, and mildew, because of the moisture content.

Crawlspace insulation installation is a relatively easy do it yourself job. With a few basic materials and hand tools, you can insulate your crawlspace in a day or two, depending on the size. Once you have added the appropriate crawlspace insulation you will find that your heating, and cooling costs will be a little lower.

Two Considerations When on a Budget

Crawlspace insulation is important to your overall income. If there is not sufficient insulation coverage, then your heating bills will be high. Depending on your budget there are two ways to insulate your attic.

  • Insulate Floor Joists - You can simply place insulation between the ceiling joists that make up the ceiling of the room below the attic and the floor of the actual attic.
  • Insulate  Walls And Floor - Another method is to add foam, or batt, insulation to the walls.

Depending on which you choose the costs could be higher. Generally insulating between the floor joists is a cheaper way to go.

Insulate Floor Joists

If you elect to place insulation between the floor joists then the right insulation is the rolled up kind that comes in varying thicknesses. You can get thicknesses from 5 1/2 inches to 9 1/2 inches. These will each have a different R- rating which is a measure of how much heat the insulation will hold in. The higher the R- number, the better the rating.

Once you have enough insulation to fill in between the ceiling joists, roll it out to the correct length and cut to size with a utility knife. Place in between joists and duplicate until entire attic is covered. You need to secure them as they are laying between the joists with a staple gun.

Insulate Wall Insulation


By installing crawlspace insulation in the walls and floor, you are going to be spending a little more in materials. The process is much the same as with the floor joists, except this time you will need to secure them to the walls and floor. By using some construction adhesive to the back of the foam insulation panels you can stick them to the walls. Lay a vapor barrier on the floor and then cover over with interlocking insulation panels.

Finishing Touches


To finish your crawlspace insulation project, you can go along the side of the crawlspace walls, and using foam insulation that is sprayed from a can, insulate the corners all the way around. This creates a tight enclosure that seals the heat above.

Crawlspace insulation is an easy project, and can be done inexpensively depending on how you plan to insulate. Get the best R- number you can and the best thickness you can.

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