Crazy paving is an irregularly shaped slab with a natural surface and edges. They come sorted into various sizes, from small to extra-large, and in different thicknesses, ranging from thin slabs to glue onto a wall to slabs sturdy enough for driveways where cars can be driven over them.

For walkways, such as garden paths, terraces, or trails, a thickness of 2–3 cm is sufficient. For driveways, the slabs should be 4–6 cm thick.

Refer to the table as a guideline.

You can also watch a video on how to choose the size and thickness of crazy paving for more details.

When it comes to quantity, it depends on the desired appearance, i.e., the degree of finishing. Significant shaping of the slabs to achieve a neat look with narrow joints results in more offcuts than minimal shaping for a rustic look with wider joints. Check out our video demonstrating how to achieve different visual styles with crazy paving, along with a video on estimating the amount of crazy paving you’ll need.

The quality of the finished result largely depends on the groundwork. Therefore, it deserves proper attention.

Ensure good drainage by avoiding gaps and unevenness, and make sure there’s a slope so that water drains away and doesn’t pool in or on the finished surface.

Try to get the foundation as flat and stable as possible. Compact it well, ensuring full contact between the slabs and the substrate.

Lay a layer of sand or sub-base, about 5 cm thick. If you don’t want grass (or weeds!) growing between the slabs, you can place a geotextile fabric under the top layer of sand.

Although slate is technically one of the most durable materials, it will, like any other material, be affected by water that carries dirt from the surface and substrate.

First, empty the pallet and spread the slabs out over an area so you can get an overview.

Plan to take advantage of the thickness of the slabs relative to the slope of the site: use the thickest slabs at the lowest point to avoid having to build up the slab too much with sand.

Find the slabs that fit best together before you start shaping them.

Crazy paving can be shaped using many methods. In general, we recommend not using an angle grinder but instead some of the following simple manual methods, which produce a neater result and avoid dust and noise.

Method 1: Ball-peen hammer and chisel/slate knife

Method 2: Cut with slate scissors

Method 3: Hewing (score and snap)

Method 4: Angle grinder

See here for 4 tips/rules for the best results when shaping crazy paving.

1 – Get an Overview

Lay out all the slabs. Take your time finding slabs that almost fit together already.

2 – Choosing a Slab

Start laying from a corner and work out in a fan shape. Place slabs with straight edges against walls or natural edges. Lay the slabs with a minimum slope of 1 cm per meter, away from the house wall. Use a level and a long wooden plank to even out the sand layer and achieve the correct slope.

Choose a new slab that fits well and place it on top of or next to the “neighboring slabs” that have already been adjusted. Ensure it just covers the opening you need to fill. Mark the slab with chalk to show how much you need to chip off. Remove the slab. Now the real work begins!

3 – Adjust the Slab

It’s important that the slate slab is stable and flat when you hammer it. Use the ball end of the hammer directly against the stone. When chipping slate, it’s about the weight and speed of the hammer. Don’t hit with crushing force straight down but at an angle, with a flicking motion like you’re playing tennis or casting a fishing rod. This way, you only stress the part of the slate you’re chipping off.

Don’t remove more than 2–3 cm at a time, and work your way gradually inward on the slab. When you’re about 1 cm from the chalk mark, start the fine chipping with a chisel or slate knife. Begin fine chipping farthest from you and work backward as you chip. The chisel/slate knife should be held slightly angled against the slate slab.

Hit quickly and with a flicking motion. You’ll get the hang of it as you go.

4 – Put the Slab in Place

Once the adjustment is complete, wiggle the slab back into place. Make any small adjustments while the slab is in position.

Lift the slab from one side and adjust the sand underneath until it no longer wobbles and is at the correct height relative to the previously laid slabs. Tap it into place with a rubber mallet or something similar. Check the height and slope one last time before moving on to the next slab.

5 – Spacing Between Slabs

The spacing (joint width) depends on the desired look. The stricter you are about achieving a narrow joint, the more shaping and waste there will be. Regardless, save the leftover slate pieces – they’re both beautiful and practical, for example, as slate mulch!

Check out our video offering 5 different ideas on what to fill the joints with!