Underlayment
# Underlayment

Underlayment may refer to:

* Underlay, a material placed underneath floor carpet, other flooring materials, or mattress bedding
* Underlayment, a water-resistant or waterproof layer used beneath many types of commercially available roofing material
   * Bituminous waterproofing, systems designed to protect residential and commercial buildings
   * SDM strength film, a kind of High Density Polyethylene (HDPE) Cross Laminated Strength Film
   * Tar paper, a heavy-duty paper used in construction
* Underlayment in road construction such as nonwoven fabric
* Underlay, a material in sewing
* Underlay, a technique in some types of surgery such as myringoplasty
* Underlay, a material in printing
