Can I Caulk Control Joints in Basement Cement?

Concrete Considerations

• Concrete is like any other material in that it is subject to the laws of nature. Natural expansion, during the warmer months, as well as contraction in cooler weather is part of the process. Concrete also shrinks during the curing phase as the materials soak up the water and condense. The average estimation of concrete expansion and contraction is 2/3-inch for every 100 linear feet of poured concrete.

Solution

• Control joints are the intelligent solution for movement in concrete slabs. These are 1/4-inch wide cuts made down into the concrete slab or pre-fabricated during the pouring process with a pre-molded resilient product that can be removed after the concrete cures. Control joints are generally placed every 15 to 20 feet on a slab although reinforced concrete can be between 40 and 80 feet, depending on the engineering requirements.

Empty Control Joint

• Since a control joint’s primary purpose is to provide movement space for the concrete, it does not serve any aesthetic purposes. As such, you can leave control joints empty, if you choose, as long as they are in areas where you do not require any visual updating. For example, unfinished basement floors are fine to leave uncaulked because they are located in an unfinished section of the house.

Caulked Control Joint

• If your floor sees any type of foot traffic or is in a visible area, you will need to caulk the control joint. Not only does caulking the joint fill it so that no dirt and debris can enter the void, you can also choose colored caulk to match your flooring material. This is useful for when a control joint carries up through a ceramic tile installation and you need to caulk the control joint with a color that matches the grout installation.