ACI Global Home Middle East Region Portal Western Europe Region Portal
Email Address is required Invalid Email Address
In today’s market, it is imperative to be knowledgeable and have an edge over the competition. ACI members have it…they are engaged, informed, and stay up to date by taking advantage of benefits that ACI membership provides them.
Read more about membership
Learn More
Become an ACI Member
Topics In Concrete
Home > Frequently Asked Questions
In This Section
Frequently Asked Questions
Submit a Question
Search other resources on the ACI website for answers to technical questions
Q. We have a basement slab that was heaving, possibly due to poor drainage or expanding soil. The slab was removed and a new one poured. It is a finished basement and we will be installing a pad and carpeting. Should the slab be sealed? A. Concrete is porous and water vapor will eventually come through the slab. Many concrete sealers may prevent the intrusion of water but not water vapor. Sealers that stop all water tend to fail after a period of time because the water collects at the barrier/concrete surface. This water destroys the bond and the barrier fails. ACI does not have a recommendation for this application. The most effective solutions, from external sources, are impermeable barriers that create an air space between the floor and barrier; or insulation directly on the surface of the floor with wood flooring on top. Both solutions are trying to create an equilibrium where moisture vapor is free to move but is no longer driven to the surface to collect by difference in pressure or temperature. References: 360R-10; 302.1R-15 Topics in Concrete: Slab
Q. We have a basement slab that was heaving, possibly due to poor drainage or expanding soil. The slab was removed and a new one poured. It is a finished basement and we will be installing a pad and carpeting. Should the slab be sealed?
A. Concrete is porous and water vapor will eventually come through the slab. Many concrete sealers may prevent the intrusion of water but not water vapor. Sealers that stop all water tend to fail after a period of time because the water collects at the barrier/concrete surface. This water destroys the bond and the barrier fails.
ACI does not have a recommendation for this application. The most effective solutions, from external sources, are impermeable barriers that create an air space between the floor and barrier; or insulation directly on the surface of the floor with wood flooring on top. Both solutions are trying to create an equilibrium where moisture vapor is free to move but is no longer driven to the surface to collect by difference in pressure or temperature.
References: 360R-10; 302.1R-15
Topics in Concrete: Slab