Concrete Floor With Control Joint

Think of it as a planned crack.

Concrete floor with control joint.

Properly placed control joints will allow concrete to shrink expand and contract reducing the tendency for it to crack. Filled in control joints in polished and stained concrete floors provided an easier to clean surface. A fresh concrete mixture is a fluid plastic mass that can be molded into virtually any shape but as the material hardens there is a reduction in volume or shrinkage. A control joint or contraction joint is intended to induce cracking in a concrete slab.

Contraction control joints are placed in concrete slabs to control random cracking. When in a rectangle shape the rectangle ratio seldom exceeds a length to width ratio of 1 5 to 1. Control joints are planned cracks which allow for movements caused by temperature changes and drying shrinkage. Control joints in concrete should be placed around the entire perimeter of a floor slab at all intersections of two different concrete structures and at regular intervals to break up large areas.

As we know control joints more properly according to the american concrete institute contraction joints are essentially planned cracks that allow for movements caused by temperature and moisture changes drying shrinkage. I ve been in the concrete floor business for over 30 years. The only thing that we can do is control where it cracks with proper concrete control joint spacing and depths at the right time. A joint cut into a slab to ensure that as the concrete slab.

I ve installed thousands of lineal feet of control joints in my concrete floors. Control joints in concrete slabs which are poured on grade on top of the ground are placed so that the concrete is in a square or rectangle pattern or shape. In other words if the concrete does crack you want to have an active role in deciding where it will crack and that it will crack in a straight line instead of randomly. Most of the time we saw the joints using an early entry soff cut saw.

One thing that i was taught in my years as a concrete finisher is that there are two things in life that are certain the first is of course death and the second is concrete is going to crack. In this post i want to help you understand the why s when s where.