How to Install Underlayment for Carpet

The life span of your new carpet is partly determined by the quality of the carpet underlayment and the soundness of the subfloor. Properly installing the underlayment really pays off in the longevity and beauty of your carpet, whether the carpet is being installed in a basement over concrete or over a wood subfloor. Intalling the underlayment yourself will also save you money.

Things You'll Need

• Box knife Tape measure Duct tape

Instructions

1. Measure the room to be carpeted. Multiply the length by the width to get the square footage. Divide the square footage by 9 to determine the number of square yards. The amount of underlayment required will be the same as the amount of carpet required. If the temperature is very cold or very hot, allow the underlayment to sit in the room before installing it for a minimum of 24 hours but 48 hours if possible, which will allow it time to adjust to the room temperature.

2. Run the seams of the underlayment opposite to the direction the carpet will be installed. Unroll the underlayment, starting along the wall, with the foam side down and the plastic vapor barrier on top. Stagger the seams in each row of underlayment. The finished installation should have a staggered appearance similar to laying bricks for a patio or sidewalk.

3. Tape the seams in the underlayment with good quality duct tape to thoroughly seal them. The room is now ready for the carpet to be installed.

4. 

   Apply a moisture barrier if installing underlayment on a concrete floor. If the concrete is smooth and level, apply the moisture barrier under the underlayment to prevent moisture from seeping up into the carpet. For concrete that is uneven, you may need to install a floating subfloor before installing the underlayment.

References

• Information on underlayment
• Preparation for underlayment