When installing a reconstituted stone bench top, proper support spacing is critical to prevent cracking, sagging, or structural failure. Unlike natural stone, reconstituted stone—made from crushed stone bound with resin—has high compressive strength but lower flexural strength, meaning it relies heavily on even support underneath.

The general rule for support spacing is a maximum of 600mm (24 inches) between supports. This applies to both timber frames and metal brackets. For overhangs, such as breakfast bars, the unsupported edge should not exceed 300mm (12 inches) unless reinforced with a steel bracket or a thicker stone profile. For islands or long runs longer than 2.4 meters, consider adding a center support beam or additional cross-bracing.

Bracket placement is equally important. Support brackets should be installed at least every 600mm along the length of the bench top. For corners or L-shaped sections, a bracket should be placed within 150mm of the corner to prevent stress concentration. Use heavy-duty adjustable brackets that can support at least 50kg per bracket, and ensure screws are anchored into studs or solid substrate.

The substrate itself must be level and rigid. If using a plywood base, 18mm structural plywood is the minimum recommended thickness, screwed at 200mm intervals. For metal frames, the frame should be stiff enough to resist twisting when pressure is applied.

Finally, always consult the manufacturer's specific guidelines, as different reconstituted stone blends may have different span limits. A well-planned support system will ensure your bench top remains flawless for decades.