When to install a Spiral Cellar
Advice for both Fit and Full installations
Option 1: New build house, house extension or house refurbishment = Fit Only Installation
The most time and cost efficient opportunity to install a Spiral Cellar is when you are already building a new home, garage or outbuilding, or building a new conservatory or extension or even where the flooring in a room is being replaced.
We recommend that any demolition work is undertaken, and once new foundations have been set, the circular hole for the cellar be excavated. The contractors will probably already have a mechanical excavator on site, and the hole can be dug in less than one day, whilst site access is at its easiest.
The hole should be shuttered such that the hole is safe, with our hole protection rings and the rest of the build programme can continue. The slab should be poured to the outside of the shuttering and the contractor will be required to provide an electric supply to the cellar and to fit two ventilation pipes (50mm UPVC pipes) within the floor construction to the nearest external wall. This will be agreed in advance by Spiral Cellars and guidance notes will be provided.
An alternative to the steel shuttering panel earth support system supplied by Spiral Cellars is to install precast concrete ‘Milton’ Rings (or similar supplier). The Milton Rings are not supplied or installed by Spiral Cellars. The rings usually sit on a concrete slab. Note that a 2.4m diameter ring x 500mm deep weighs approx 1.05 tonne. The step irons need to be cut off. If this method is selected please confirm for advice on the minimum internal diameter of the rings - generally a 2.4m internal diameter ring is required for Original Spiral Cellars and 2.6m internal diameter for White Spiral Cellars, but we need to confirm the details for each particular job. Please consider cost, delivery and plant required for Milton rings, in addition to access issues on your site.
Spiral Cellars should be booked to install the cellar between first and second fix stage of the build. Our schedule is normally booked 12 weeks ahead. To re-schedule the installation date we require 28 days notice as per our Terms and Conditions.
The Spiral Cellars team then supply, deliver and install the cellar. The construction method for the cellar involves: installing the butyl liner and fleeces, casting the base, constructing the cellar modules, casting a reinforced concrete ring in-situ, if required. The trap door and ventilation pipes are connected and the installation is complete. On a well prepared site, this process will take 3-5 days. The final electrical connection should be completed by the contractors’ certified electrician.
What the contractor will be required to do:
The ‘fit only’ option for the installation of a Spiral Cellar has a number of critical elements that must be executed as per our specification. These elements will be checked ahead of our attendance. Any variances will become chargeable.
1. The contractor should excavate a hole as per the structural calculations package, on average 2300-2500mm diameter and up to 3600mm deep (depending upon cellar size selected – the exact dimensions would be confirmed by Spiral Cellars once the engineering calculations have been prepared, which are project specific). Any larger excavation will result in additional backfill and hence incur additional costs to the client/contractor.
2. The hole should be protected with our steel shuttering rings. This will be delivered to site at 1 week’s notice, prior to the excavation date. All bolts, washers and nuts are supplied. Follow our ‘Guidelines for Contractors – hole preparation’ spec sheet.
3. VENTILATION PIPES: Once the excavation is complete and made safe, it is critical that the preparation for the vent pipes is given consideration. 2 x 50mm internal diameter UPVC pipe with solvent welds must be installed in line with the Spiral Cellar’s designs. Where possible 90 degree bends must be minimised. At the external end the 50mm pipes can be terminated 100mm beyond the brickwork if they are contained within the cavity. If the vents are to be outside the external wall, the 2 x 50mm pipes can be terminated side by side and protected. The low level ‘cold – in’ pipe will be 300mm above hard landscape, the high level ‘warm – out’ pipe will be at 2000mm height, unless agreed differently at survey stage. All pipe ends to be taped up. Vents to be marked ‘upper’ & ‘lower’. Follow our ‘General Guidelines for Contractors’ spec sheet. Please note, the vent pipes must not have hot water pipes for radiators or under floor heating set over. The vent pipe run must be executed as per our specification.
4. ELECTRICAL SUPPLY: The cellar requires a power supply for lighting and for the motorised door (if applicable). An electrical feed to the cellar will need to be installed within the floor construction in conduit with no junctions. Leave approximately 3.5m of cable within the cellar. Tape ends. Provide a 3amp fused spur for cellar supply and to make final connections outside the cellar. Follow our ‘General Guidelines for Contractors’ spec sheet.
5. FINISHED FLOOR LEVEL DATUM: A datum level mark on a wall or similar indicating Finished Floor Level (FFL) is to be provided within 3m of the cellar location on DAY 1 of our installation. – this cannot be changed thereafter.
6. The Project Manager will be in touch in the run up to the installation to agree a suitable start date for the installation and answer any queries that may arise. A pre-installation visit may be conducted to confirm the site and excavation are ready for our team’s arrival. We will expect to be able to arrive at the site on the agreed date, remove the protection and fit the cellar, reinforce concrete ring (if required), make final connections to the ventilation pipes and then finally fit the trap door. Any delays/incomplete works which cause the project to run beyond the scheduled programme will be charged in accordance with our terms and conditions. If there are any doubts concerning the installation procedure and requirements the contractor should contact the main office for direct referral to our Project Manager for technical guidance, or to arrange a site meeting.
7. We will expect good, clear, safe site access and an area for materials in line with the discussions and agreements at site survey stage. The HSE do not consider other teams working overhead or obstructing scaffold to be a safe working environment.
Option 2: Retro fit scenario = Full Installation
We are able to undertake the full installation into existing buildings, even when the property is fully occupied. We can also carry out a full installation on refurbishment and new build projects if the contractor prefers not to do the excavation. We dig and remove the spoils by hand, and as such we are able to install in most ground floor rooms or basements regardless of construction build up. For the Original Spiral Cellar, this can take 5-6 working days. For the White Spiral Cellar, this is more likely to be 8-9 working days. Access for materials and skip positions need to be considered carefully at site survey stage.
The Spiral Cellar team will also organise skips for removal of waste, gain the necessary permits from your local authority, and supply all building materials, waterproof liner, Spiral Cellar modules, trap door and lighting.
