450mm Solid Top Poly Manhole Cover and Frame
SOLID TOP COVER & FRAME
| Application: | Domestic driveways |
| Loading: | 3.5 Tonne - 35kn |
| Lifting Key: | N/A |
| Product Features | |
| Cover & Frame | Solid top. Black polypropylene. |
| Locking | Dual locking (Cover screws to frame & frame screws to chamber top). |
| External Dimensions: | 550 (W) x 50 (H) |
| Clear Opening: | 450 |
A 450mm Solid Top Polypropylene (Plastic) Manhole Cover and Frame is a lightweight, corrosion-proof circular access lid designed to seal 450mm plastic inspection chambers and shallow drain risers in non-vehicular domestic areas.
Primary Uses & Key Features
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Pedestrian & Garden Drainage: Ideal for installation in domestic lawns, garden borders, flower beds, and footpaths where there is no risk of vehicle traffic.
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A15 Light-Duty Rating: Built to safely support pedestrian foot traffic, wheelchairs, and domestic garden equipment like lawnmowers (tested to a 1.5-tonne / 15kN load limit).
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Universal 450mm Chamber Compatibility: Engineered to fit directly onto standard 450mm circular plastic inspection chamber risers from major underground drainage manufacturers.
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Rust & Corrosion Resistance: Made from high-density polypropylene, it will not rust, rot, or degrade over time when exposed to standing water, damp soil, or garden fertilizers.
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Child Safety Features: Features integrated screw-down locking points around the frame perimeter, allowing the lid to be firmly bolted down to prevent children from accessing the deep chamber below.
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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 concernsEnter your postcode on the product page to check your delivery area. We’ll confirm the delivery date after your order is placed.
How do you cut a 450mm poly frame to fit tight against a wall or step?
The polypropylene frame can be easily trimmed or notched using a standard handsaw, angle grinder, or jigsaw with a coarse plastic-cutting blade. Trim only the outer bed flange while keeping the main circular seat structural and intact.
Can a 450mm plastic cover be painted to match surrounding paving or turf?
Yes, but you must first prime the surface with a specialized plastic/polypropylene primer spray. Once primed, you can apply outdoor-grade masonry or exterior metal/plastic paint to blend the lid into surrounding patio slabs or artificial grass.
What size screws should be used to lock down a poly cover?
Use 5mm x 40mm (or 5mm x 50mm) grade 316 stainless steel countersunk wood/decking screws. Stainless steel is essential to ensure the screw heads do not rust and strip out when you need to undo them for maintenance.
Why does a 450mm plastic cover feel flexible compared to cast iron?
Polypropylene has natural elastic flexibility under load, whereas cast iron is rigid and brittle. This small amount of flex allows the cover to absorb minor foot impacts without cracking or splitting, as long as it stays within its 1.5-tonne A15 weight limit.
How do you seal a poly cover against water ingress and foul odours?
Many 450mm poly covers feature an integrated rubber seal pre-fitted into the underside channel of the lid. If your model is plain-seated, you can run a thick bead of silicone sealant or petroleum grease into the frame recess before screwing the lid down.
