Fixing Loose Garden Steps

A Practical Guide to Re-Bedding Stone, Brick, or Slab Treads

Loose steps are a common problem in outdoor settings where stone, brick, or slab treads have been laid using mortar. Unlike standard bricks, which often feature a “frog”—the scooped-out depression on one face that helps mortar grip—the flat surfaces of slabs and natural stone offer little for mortar to cling to. This lack of mechanical suction can lead to the mortar failing after a season or two, especially with frost and water movement.

Why Traditional Mortar Fails

When building or repairing steps, it’s common to lay the tread (the horizontal surface) onto a bed of mortar. While this works well with bricks laid frog-down—because the mortar fills the depression and forms a tight mechanical bond—stone or slab treads usually have flat, non-porous undersides. Once the mortar sets, it may not create a lasting bond unless both surfaces were prepared and keyed-in properly. Over time, foot traffic and weathering cause the tread to work loose.

A Long-Term Fix: Using Grit-Peel Adhesive

One effective solution is to use a construction adhesive known as GripFill—a high-grip exterior adhesive that acts like a bonding agent between the step surface and the underlying base.

Here’s how to do it:

1. Choose the Right Conditions
   The success of this method depends heavily on dry weather. Ideally, the steps and surrounding masonry should have remained dry for at least seven consecutive days, especially during summer. This ensures no trapped moisture affects adhesion.
   
2. Clean the Surfaces
   Remove all old mortar, dirt, dust, and loose debris from both the tread and the base. A stiff wire brush and vacuum or blower help here. The cleaner and drier the surfaces, the better the bond.
   
3. Apply Grit-Peel Adhesive
   Grit peel typically comes in a cartridge and is applied using a standard sealant gun. Run beads of adhesive generously across the underside of the tread, especially near the edges and corners.
   
4. Set and Weight the Tread
   Carefully place the tread in position and apply even weight across the surface—heavy paving slabs or buckets of sand work well. This pressure helps ensure a strong bond while the adhesive cures.
   
5. Curing Time
   Leave the weight in place for at least 48–72 hours. Follow the manufacturer’s recommendations for full curing time.
   
6. Repoint Any Gaps
   Once the tread is bonded, repoint around the joints with mortar to seal the edges and prevent water ingress. This will also help stabilise the surrounding structure.
   

With the tread now glued and repointed, your step should stay solid for many years. This method avoids the common pitfall of relying solely on mortar where there’s no mechanical bond and adds an extra layer of stability against the elements.