Add Crawl Space Insulation to Stop Heat Loss and Save Money

Safety Precautions

• Enter the crawl space carefully. Using a bright light, inspect for any wildlife that may already be down there.


• Wear long sleeve shirt and pants to cover as much skin as possible.


• Wear a mask to avoid breathing in fibers.

Supplies For Installing Crawl Space Insulation

These instructions for installing insulation in a crawl space floor are intended for crawl space floors that are open on the underside. Crawl space floors usually have exposed floor joists with nothing inbetween them. This is where the new insulation needs to be installed.

Exception would be if you are adding additional crawl space insulation to increase the R-factor.

You can use rolls or batts of insulation. How much crawl space floor insulation you need is determined by where you live. You won't go wrong by having 6 - 10" of insulation in your crawl space floor.

Below you will find instructions for installing batts or rolls of insulation in your crawl space floor.

Instructions for Installing Rolls or Batts of Insulation

1. Determine the spacing between the open crawl space floor joists. You should come up with a number 14-1/2" or 22-1/2".


2. Purchase the correct width of insulation in a quantity to cover the square footage of the crawl space floor.


3. If using batts of insulation, place the batt all the way up into the space between two floor joists - PAPER SIDE UP.
   
   Note: The paper on the insulation batt is a vapor barrier. This barrier needs to be installed with the vapor barrier on the top side. You should not see the paper after you have installed insulation in your floor.


4. Use a metal insulation hanger placed every 18 - 24" to hold the batt between the crawl space floor joists.
   
   An insulation hanger is simply a piece of metal that springs inbetween 2 floor joists and the batt rests on top.


5. Continue placing batts of insulation up against the last one already installed until all of the crawl space floor insulation has been installed.
   
   Use a utility knife to cut batts of insulation by laying them paper side down on top of a board or other hard surface, providing a cutting surface. Drag the knife across the width of the batt a couple of time applying light pressure while compacting the material.


6. You may encounter pipes or other portrusions through your floor. Cut batts around all obstacles as required.


7. If you encounter a water supply line to an exterior hose bib, place the new insulation under the pipe so that it stays on the warm side of the new insulation. This will avoid freezing of this water line.