Guide · 4 min
Control joints: when to cut and how deep
Concrete shrinks as it cures and cracks. The control joint tells it where. Doing it wrong —late, too shallow or crooked— lets the crack start where you don't want it.
of the slab thickness
typical cutting window
always wet cut
When: not too early, not too late
Cut as soon as the slab bears the saw's weight without raveling aggregate (early-entry), usually 6 to 18 hours depending on weather and mix. Waiting too long lets the crack beat you.
How deep and how far apart
Depth ≈ ¼ of the slab thickness, to create the weak plane that guides the crack. Space joints by thickness: square panels, no long narrow strips.
Wet cutting and a straight line
Always wet cut: water cools the diamond blade, controls dust and extends its life. Snap a line and follow the saw's guide — don't force full depth in one pass.
Takeaway
Cut early (once the slab bears it), at ¼ of the thickness, in square panels and with wet cutting. The SIMAQ concrete & asphalt saw includes a guide and water tank to do it right.
Frequently asked
Concrete or asphalt blade?
A specific diamond blade per material. The saw includes two extra 400 mm discs (concrete and asphalt).
