Do I need to seal my driveway or concrete?

A sealer is a surface treatment. It reduces water and oil absorption, which helps with staining, and on decorative finishes such as exposed aggregate or stencilled concrete it holds the appearance and binds the surface. It does not add strength and it does not prevent cracking.

What it does and does not do

• Does reduce oil, tyre and organic staining, which matters most on light coloured decorative finishes.
• Does reduce surface dusting and minor abrasion.
• Does not stop cracking, which is a function of the slab, the base and the joints.
• Does not prevent movement at joints, which is what control joints are for.
• Does need recoating, typically every few years depending on exposure and traffic.

Cracking is a different question

Concrete shrinks as it cures and moves with temperature, so it cracks. Control joints exist to decide where. Cracks that follow a joint are working as intended. Cracks that wander across a slab, that are stepped, or where one side has dropped, indicate a base or drainage problem underneath, and no surface treatment addresses that.