No Wall-to-Wall Carpet Installed in Wet Areas
No climate specific information applies.
Water splashing or spraying out of sinks and tubs; rain and snowed tracked in on wet shoes; and water vapor in the air from cooking, laundry, and bathing – all contribute to wet floor surfaces. When the floor surface is covered with carpet, it can take longer for the moisture to evaporate, leading to mold and mildew problems and the carpet can hide serious water spills that may result in warping, swelling, and rotting of the subfloor. To minimize the opportunity for mold growth and structural damage, carpet should not be installed in bathrooms, kitchens, entry ways, laundry rooms, or utility rooms. Instead water-resistant hard-surface flooring should be installed in these areas.
The design and construction of bathrooms and other wet areas of the home should be part of a comprehensive water management strategy that includes the following:
- Hard surface flooring
- Properly installed air sealed shower and tub enclosures, as described in Solution Center Guides Moisture-Resistant Backing Materials at Walls Behind Showers and Tubs and Walls Behind Showers and Tubs.
- A mechanical exhaust system, as described in the Solution Center Guide Bathroom Exhaust and Kitchen Exhaust.
- Paints and wall finishes specifically designed to handle high moisture levels.
See the ENERGY STAR Water Management System Builder Checklist for additional guides to help you design and construct a home with reduced risk of water damage.
Figure 1. Mold on the Wall, Baseboard, and Carpet. Wall-to-wall carpet installed in a bathroom will likely become wet, not dry completely, and encourage mold growth, which is visible on this wall, baseboard, and carpet.
Several hard-surface flooring products are appropriate for areas of the home that are likely to get wet – ceramic tile, stone, and vinyl flooring are all good choices.
The following flooring materials are hard surface but are still not recommended for areas especially prone to water spills.
- Hardwood flooring. Although usually sealed and water proofed, hardwood flooring is not generally rated for excessive and repeated exposure to water.
- Laminate flooring. Laminate flooring is made from either melamine resin or linseed oil and wood chips. Although laminate flooring can tolerate some exposure to water, excessive saturation, spills, or standing water will damage the material over time.
- Bamboo, cork, and alternative flooring options. Other types of modern sustainable flooring options such as bamboo and cork are not appropriate for wet areas as they will warp and wear poorly when exposed to the amount of water expected in a bathroom.
Due to the amount of water that can be introduced into the home from showers, tubs, and toilets, consider designing and building the bathroom, the laundry room, and/or the kitchen as a true “wet room” (BSC 2009). A designed wet room is built to contain and remove excessive water, keeping it from entering the other parts of the house.
How to Select Water-Compatible Flooring
- Select appropriate flooring materials for wet areas including bathrooms, kitchens, entryways, laundry rooms, and utility rooms (EPA 2012):
- Ceramic tile. Ceramic tile is a clay-based material that is kiln dried and installed in mortar or thin set over a cement backer-board. Once installed, the tiles are treated with a water-resistant finish that protects the floor and subfloor. Relative to other flooring types, ceramic tile is moderately priced.
- Stone. Stone is a natural product that is installed like ceramic tile over a cement backer-board in thin set. Natural stone can be marble, granite, travertine, or terrazzo and must also be treated with a waterproof coating. Stone is the most expensive flooring option.
- Vinyl flooring. Vinyl flooring comes in rolls, planks, and tiles, and is composed of polyvinyl chloride (PVC) resin along with additives such as plasticizers, stabilizers, pigments, and fillers (EPA 2012). Vinyl flooring is relatively inexpensive compared to ceramic tile and stone flooring. When properly installed, vinyl flooring provides a waterproof barrier between the bathroom and subfloor. Vinyl flooring that comes in rolls is installed using an adhesive that is painted or sprayed directly on the subfloor. Vinyl planks and tiles usually have self-adhesive peel-and-stick backing material.
- Sealed concrete flooring. When sealed, concrete provides a non-pervious, water resistant surface that is ideal for wet areas. Concrete’s thermal mass lends itself to radiant floor heating. Clear chemical sealants must be reapplied every 1 to 2 years. The sealant can contain particles to provide traction on wet floors.
Figure 2. Select Flooring Appropriate for Wet Area. The toilet, sink, bath, and shower are all significant sources of water, and flooring options need to be selected that do not absorb water and are not damaged by water.
How to Make a True “Wet Room” (BSC 2009)
- Install a water-resistant flooring material (as listed above and according to manufacturer’s specifications) that extends wall to wall and is continuous under fixtures and cabinets, with only those penetrations needed for plumping pipes.
- Caulk and seal all plumbing pipe penetrations.
- Install water-resistant baseboard material that is sealed to the floor or install floor material that is turned up at the walls and sealed at the corners.
- Install a floor drain that is properly attached to the home’s sewer system.
- Install a raised sill at doorways to contain any excess water that may flow toward the rest of the home.
- Make sure all drywall is installed at least ½-inch above the finished floor to reduce the chance of wall materials coming into contact with and absorbing water.
Avoid installing carpet in areas that routinely get wet or have an increased likelihood of getting wet such as bathrooms, kitchens, entryways, laundry areas, and utility rooms.
When home building, employ a comprehensive water management strategy.
Avoid installing carpet in areas that are likely to become wet.
Zero Energy Ready Home Notes
The DOE Zero Energy Ready Home program requires that builders comply with EPA Indoor airPLUS. The Indoor airPLUS checklist (Item 1.11) requires that builders -install only water-resistant hard-surface flooring in kitchens, bathrooms, entryways, laundry areas, and utility rooms.
ENERGY STAR Certified Homes Notes
The ENERGY STAR Certified Homes Water Management System Builder Checklist recommends that wall-to-wall carpet not be installed within 2.5 feet of toilets, tubs, and showers.
The ENERGY STAR Certified Homes Water Management System Builder Checklist recommends that wall-to-wall carpet not be installed within 2.5 feet of toilets, tubs, and showers.Zero Energy Ready Home
The DOE Zero Energy Ready Home program requires that builders comply with EPA Indoor airPLUS. The Indoor airPLUS checklist (Item 1.11) requires that builders install only water-resistant hard-surface flooring in kitchens, bathrooms, entryways, laundry areas, and utility rooms.