Adding a Glass Wine Cellar Door to an Existing Spiral Cellar

Replacing the lid on an existing spiral cellar is one of the most common jobs we are asked about. The cellar is already there, the opening is already formed, and what sits over it is usually a dated timber or metal cover that is heavy, awkward and blocks every bit of light.

This is a retrofit, which makes it a different exercise from specifying a cellar from scratch. The door is designed around the opening you have rather than the opening being formed to suit a standard product.

Why people replace an existing cellar lid

Light and view. A solid lid makes the cellar a hole you climb into. Glass turns it into something you look down through — the staircase, the racking, the bottles.

Operation. Hand-lifting a timber or steel lid gets old quickly, and a cellar that is awkward to open stops being used. Gas struts or a motor change that.

Appearance. A flush glass door reads as considerably more refined than a dated cover sitting proud of the floor.

The detail that makes a retrofit look designed

Spiral cellars are formed in concrete, and the top of the shaft almost always leaves an exposed concrete lip around the opening. Left visible under clear glass, it is the thing that makes a retrofit look like a retrofit.

Our solution is a painted border applied to the underside of the glass, shaped precisely to follow the curve of your spiral. It conceals the concrete lip and gives a clean transition from the floor finish down into the cellar, so the finished door reads as though it was designed for the space from the outset rather than fitted over what was already there.

It is a small detail and it is the one clients notice most.

Circular or semi-circular

A round cellar means a round opening, and there are two configurations.

A full circular lid gives a clean symmetrical result — it reads almost like a porthole in the floor, with the whole opening on display. It is the better-looking option where the panel can be raised comfortably.

A semi-circular hinged door lifts over one half while the other half stays fixed. This suits openings where a full panel would be heavy or awkward to raise, or where a raised full lid would swing into a walkway. It also works well where the cellar stair is positioned so that you descend on one side.

Neither is universally better. The decision usually comes down to the weight of the panel and what is immediately around the opening. Both are made to measure — see our circular wine cellar doors and bespoke spiral cellar doors.

Measuring and matching an existing opening

The panel has to relate accurately to the existing structural upstand or frame, so this starts with measurement rather than product selection. Span, support and floor loading are assessed by a structural engineer rather than assumed from the old lid.

One dimension to establish before anything else: our frame takes up 100mm or more of the finished hole size. On a spiral cellar you generally cannot enlarge the opening, so the clear access you end up with is meaningfully less than the shaft diameter. Work out the clear access you need at the survey, not after the drawing is approved.

The glass, the frame and everyday safety

Structural floor glass is toughened and laminated, with bonded layers so the panel retains integrity if one layer is damaged. Our standard build-up is 25.5mm, designed against BS EN 1991-1-1 — typically 150kg/m² distributed plus a 2.0kN concentrated load domestically. Impact performance is classified to BS EN 12600. Thickness is confirmed per project against the opening size, loading and support.

Supporting steelwork is manufactured under UKCA certification to BS EN 1090-2.

Anti-slip treatment is applied to the walking surface where wanted — our invisible treatment reaches a Pendulum Test Value of 68 and lasts around five years without affecting clarity.

Two limitations worth stating. A cellar door cannot guard its own opening: a continuous staircase handrail cannot pass through a closed floor, which is why a glass cellar hatch sits outside full Building Regulations compliance as stair access and should not be the primary route into a habitable room. And a motorised panel takes around 40 seconds to open, so it is not a means of escape. The space below needs a secondary escape route, and that risk assessment sits with you and your building control officer.

How the new door will open

Gas struts store energy that counterbalances the weight of the panel, so a heavy circular lid can be raised with far less effort than the lid you are replacing. Struts are matched to the panel size, weight and opening geometry rather than a fixed formula. Maximum 2000 × 1000mm.

Motorised removes the lifting entirely and is usually specified where the panel is large or where whoever uses the cellar cannot comfortably lift glass. Electric systems are specified per project against the size and weight of the panel, and are supplied with a UPS backup as standard so a power cut mid-use does not strand the panel. Maximum 2300 × 1100mm.

On a retrofit, how the mechanism sits within the existing opening and floor build-up is the constraint that most often decides between the two. Doors can be supplied lockable.

Lead time is 6–8 weeks for gas-strut and 10–12 weeks for motorised, from approved drawings. Nothing is stocked. The installation guide covers handling and fitting, and our FAQs answer the questions that come up most.

Talk it through

Send us the diameter of your opening and a photograph of the existing lid and we can tell you what is possible.

Call 0114 229 1578 or email sales@glassfloorsystems.co.uk. Prices are on the circular cellar door and bespoke spiral cellar door pages, with indicative figures for every product type on the pricing guide.