Do You Need Special Tape to Install Floor Underlayment?

You don’t always need special tape to install floor underlayment, but using the right type of tape can make a big difference in the performance and durability of your flooring system. Here’s a quick breakdown to help you decide:

✅ When You Do Need Special Tape:

• Moisture Barrier Underlayments: If your underlayment includes a vapor barrier (common for installations over concrete), you need a seam tape to seal the seams and keep moisture from seeping through.  Here is another article that could help with the materials you need for the jobsite.

• Sound-Reducing Underlayments: Taping seams tightly helps maintain the acoustic integrity of the underlayment.  Often times, the underlayment like QuietWalk family of underlayments come with a self-sealing lip and tape system.

• Manufacturer Requirements: Some underlayment brands require specific tape to maintain warranties.

❌ When You Might Not Need Special Tape:

• Attached Underlayment: If your flooring already has underlayment attached (common with some laminate or LVP products), you likely won’t need separate tape. However, it is always good practice to protect from beneath with a 6-mil poly sheeting product like MoistureBlock.

• Tongue-and-Groove Underlayment: Some underlayments interlock and may not need tape for installation.

• Non-moisture-sensitive areas: In dry areas (like upper levels with plywood subfloors), regular duct tape or packing tape may be fine—if the underlayment isn’t a moisture barrier.