Kahrs Installation Items, Combo Underlayment 118672 Use it over regular sheet

Use it over regular sheet rock

There's no need for other sealers on top if it's maintained regularly

or other harmful chemicals

It's also great for grungy jobs

Fights indoor air pollution – prevents off-gassing of toxic chemicals in carpet fibers

Kahrs Installation Items, Combo Underlayment 118672 Use it over regular sheetGreat all in one underlayment for moisture protection and sound reduction Khrs Combo Underlayment is a two ply polyethylene film with flexible polystyrene granules sandwiched between to provide a dual moisture barrier with a thickness of 3 mm. It has a compression recovery of 80% (ASTM D1055) without loss of resilience. It also has a good sound rating (ASTM E 90 and E 492, STC = 59, IIC = 59) which means it provides very good sound deadening