How to Install Expansion Joints When Pouring a Concrete Driveway

Expansion joints prevent cracks from developing in newly poured concrete when subjected stress. Concrete shrinks when it hardens. This can cause stress and cracks. To prevent this from happening, install expansion joints into a newly poured slab. Expansions are spaces created within the slab that allow for movement during stress or temperature change.

Supplies

• Pre-made expansion joints


• Thin pieces of wood


• Jointing trowel

Premade Expansion Joint

1. Install expansion joints while the concrete is being poured. Pre-made expansion joints can be used for slabs, which require numerous pours. These are usually made from a cork or piece of wood.


2. Install the joints inside the frame on each of your pours.


3. Place the expander between the first pour and the next pour made.


4. Join each new piece of concrete with an expander. Put them in as the pours are done.


5. Leave the joints in the concrete.

Trowel Expansion Joint

1. Create expansion joints with a joint trowel. Trowel expansion joints relieve the tension caused by the curing of the concrete. This procedure can be used if you are not using full expansion joints.


2. Place a two by four stud across the curing cement.


3. Slice the concrete with the joint trowel along the lumber using it as a guide. This procedure is often used in sidewalk projects.

Saw Expansion Joint

1. Employ a concrete saw on cement that has already set when it is found that an additional expansion joint is needed. Make the joint approximately one-half inch thick.


2. Use a chalk line or straight edge and construction chalk to set the line for the cut.


3. Run the blade across the concrete.