A moisture-barrier underlay can be useful in homes where spills, pet accidents or other liquids are a realistic risk. Manufacturer material from Airstep explains that liquid can pass through the carpet into the underlay, where contamination may remain even after the carpet surface has been cleaned. A barrier layer is intended to reduce the amount of liquid reaching the absorbent part of the underlay, which can make recurring stains and odours less likely. It is still important to clean spills promptly and to choose an underlay that is suitable for the carpet, subfloor and room. Product construction and warranty conditions vary, so the exact moisture-protection claim should be checked for the underlay being quoted.
