163 Square Raising Piece (commonly used in underground drainage and plumbing systems) is a durable PVCu riser component designed to extend and elevate specific drainage fittings—such as bottle gullies or shallow access points—up to the required finished ground level.

• Elevating Surface Drainage Components: Used to extend the height of underground bottle gullies or yard gullies so that their grates match the final surface level of patios, driveways, or paved areas.

• Accommodating Level Adjustments: Helps bridge the gap when ground levels change or when thicker paving slabs and sub-bases are installed, ensuring the drainage inlet doesn't end up trapped below the surface.

• Maintaining Access and Maintenance: Keeps inspection and entry points accessible at ground level, allowing for easy removal of debris and unblocking.

• Creating a Secure Underground Fit: Provides a tight, push-fit or spigot connection directly onto compatible underground drainage components to maintain a watertight and stable system.

Available for collection from our Rugby branch or local delivery using our own fleet.

Delivery is kerbside and the final offloading position is always subject to safe access and the driver’s discretion.

Please tell us before delivery about:

• Narrow roads or restricted entrances
• Parked vehicles or limited turning space
• Overhead cables, trees or other obstructions
• Soft, sloping or unsuitable ground
• Any other access concerns

Enter your postcode on the product page to check your delivery area. We’ll confirm the delivery date after your order is placed.

What is the primary purpose of a square raising piece?

A raising piece is designed to extend the height of a drainage gully or access box vertically, allowing the top grate to sit flush with the finished ground level when landscaping or paving layers are thicker than anticipated.

What size of drainage gully does a 163 square raising piece fit?

It is specifically engineered to fit standard 163mm square drainage inlets, bottle gullies, and hopper heads commonly used in domestic underground drainage systems.

Can multiple raising pieces be stacked together?

Depending on the specific manufacturer and model, some raising pieces can be stacked to achieve greater heights. However, for deep level adjustments, it is usually recommended to use a standard inspection chamber riser or adjust the main pipework to prevent structural instability.

How do I install a square raising piece securely?

Clean the collar of the existing gully or chamber, apply a suitable lubricant or waterproof sealant if required by the manufacturer, and push-fit the raising piece firmly into place. Ensure it is level before laying surrounding paving or concrete.

Do I need to seal the joint between the gully and the raising piece?

Yes. Using an exterior-grade waterproof sealant or checking that the built-in rubber seal (if present) is properly seated ensures that groundwater or surface run-off does not leak out into the surrounding soil before reaching the drainage pipe.

Can raising pieces be cut down if they are too tall?

Some plastic raising pieces can be carefully cut down using a fine-toothed hand saw if you need a non-standard, custom height adjustment. Always check the manufacturer's instructions to ensure cutting won't compromise the interlocking joint or structural integrity.