For small cracks smaller than 25 mm, sealer can be used. For larger cracks, even a slurry seal will not fill cracks in the pavement. The aggregate in a slurry seal is meant for minor imperfections, not cracks. Cracks come in many sizes, and we repair cracks smaller than 2.5 cm wide, but ideally less than 2 cm. Larger cracks need a different application. Crack filler helps to slow the progress of pavement damage. Once it has started, the damage tends to progress at an increasing rate. The sooner cracks are filled, the longer you can delay the damage.