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How Much Underlayment Do I Need to Buy?

How Much Underlayment Do I Need to Buy?

Dear Bob and Betsy,
I’m getting ready to install my flooring in my living room but I still need the 3-in-1 underlayment. The room is about 350 square feet, maybe a little bit less. Do I need to cover the entire floor? How much underlayment do I need to buy?
– James K.

Dear James,

This is a common question. Since underlayment isn’t actually seen, many homeowners think that they might be able to get away with leaving a little room on the sides of the flooring, and not buying the full amount needed. That’s dangerous and it could decrease the life of your flooring.

As a rule, we suggest buying as much or more than you need. If your room is about 350 square feet, you will probably want to buy four rolls of 100 square foot underlayment. Most underlayment is sold in packages that cover 100 square feet, so the math is easy.

Here’s why you’ll want to ensure your underlayment covers the entire subfloor when you install.

1. It’ll reduce the amount of noise in your room.

Because you’re buying 3-in-1 underlayment, you want to get the maximum benefit of the noise reduction. Without the 3-in-1, your floors might echo, making your house a little noisier than you’d like. To get the full noise reduction, make sure you install the underlayment throughout the room.

2. It’ll decrease your risk of moisture damage.

Moisture and laminate flooring don’t mix very well. That’s especially true when moisture is found underneath the floor boards. To prevent warping caused by leaks or cracks in the subfloor, you need to cover the entire room with underlayment.

3. It’ll extend the life of your floors.

The underlayment is there to stabilize your flooring and make it more comfortable. If there are sections without underlayment, you risk your floors becoming damaged from the bottom up. This can cause serious harm to your flooring over time. Although laminate planks are easy to replace, you don’t want to have to go through that burden if it’s not necessary. Install your subfloor throughout the entire room, from corner to corner, for the best results.

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  1. we are thinking of pulling the carpet up in our living room. The floor is cold in the winter due to the basement is concret. Will laminate flooring the floor ever colder or there a way to put a warm under layment to help keep some of the cold out.

    • Ashley Arndt

      Hi Margaret! Yes, you can definitely add an insulating underlayment underneath your laminate floor to make it warmer. We recommend Roberts Super Felt Premium Underlayment. This underlayment also comes with a vapor barrier, which you need if you are installing over a concrete sub-floor. Good luck with you installation and feel free to call us if you have further questions! 1-800-520-0961!

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