To calculate the quantity you need:

Measure the area in square metres (m²).

Decide on your desired depth—typically 25 mm for decorative borders and pathways, or 50 mm for driveways and heavier use.

25 mm depth → 420 kg per 10 m² (21 small bags)

50 mm depth → 850 kg per 10 m² (1 bulk bag)

Disclaimer: Actual amount needed can vary from job to job.

Yes, installing a permeable weed suppressant membrane :

Prevents weeds from growing through the stones

Keeps the chippings cleaner by stopping soil splash

Allows water to drain freely through the surface

Yes, provided you:

Lay a properly compacted sub-base (e.g., MOT Type 1 or crushed concrete) of at least 150 mm

Install a geotextile membrane to separate soil from the sub-base

Use a minimum of 50 mm depth of chippings over that sub-base
This combination ensures stability under tyre loads and prevents rutting.

Raking: Lightly rake the surface every few months to even out wear patterns.

Weed control: Spot treat any weeds that penetrate the membrane, or replace small sections of fabric as needed.

Cleaning: Remove debris such as leaves and dirt, then occasionally rinse with a garden hose or use a low pressure pressure washer to remove any algae buildup.

Planters: Yes, use a thinner layer (10–20 mm) on top of potting mix for decoration and moisture retention; ensure pots are sturdy for the extra weight.

Pathways: Ideal for decorative garden paths; use a 25–30 mm depth over a compacted sub-base and membrane. Note that larger stones can be uneven underfoot, consider pairing with stepping stones if preferred.