SYSTEMS SPECIFICATION

1.0 Introduction

The FLODEF system is a complete system designed to protect a whole property and minimise the effects of normal flooding.  The system is installed below ground and the works are undertaking in accordance with BS 8102.  The above ground works are designed, manufactured and installed in accordance with BS PAS 1188 - III.  In addition the customer will be able to take out a service package for the maintenance of the system to ensure that it’s performance is maximised when deployed. Flodef strongly recommend clients to take out a Service Contract.

2.0 Site / Pre-Installation Survey

2.1 New Build projects will require a full set of scheme drawings of each property type along with full details of ground conditions, topography, flood history, services, drainage details, hard and soft landscaping etc at an early stage. If the Flodef system is unsuitable this will be notified to the developer concerned. The development will need to be designed to take account of and properly incorporate the Flodef system.  A pre-fit survey will be carried out if requested to check that the pre-installation works have been completed correctly, otherwise the survey will be undertaken on the first day that the installation team is on site. A final measure will be undertaken on site prior to installation commencing and any variances notified.

2.2 With existing properties a full site survey is required to establish ground conditions, topography, flood history, services, drainage details, hard and soft landscaping etc. If the Flodef system is unsuitable this will be notified to the client. A final measure will be undertaken on site prior to installation commencing and any variances notified.

2.3 Where ground levels vary around the property the system can be stepped up or down to account for reasonable changes of level. Where level changes are significant this will need to be taken account of in the design of the system and where retaining walls are to be incorporated the system may not be required on all sides of the building depending on anticipated flood levels.

3.0 Tolerances

The system is designed with standard industry tolerances the system can be designed to be able to take account of excessive tolerances particularly if the property is not square or walls or corners not plumb.

4.0 System Below Ground

4.1.1. All barrier works are to be carried out in accordance with BS 8102 and the anti-flood devices fitted comply with BS EN 13564-1.

4.1.2 All service entry points are to be properly sealed at entry point with a sealant used in accordance with manufacturers recommendations.

4.1.3. All foul drains entering the building are to have suitable non-return valves fitted to comply with BS EN 13564-1 and are to be properly sealed at each entry point into the building with a sealant used in accordance with manufacturers recommendations. Where requested by the client inspection chambers can be incorporated in the installation of the non-return valves.

4.1.4. Existing storm drains and foul gullies etc may require to be moved away from the building to accommodate the system and this will be undertaken in accordance with current codes of practice.

4.2 New Build Systems

4.2.1 The construction needs to be carried out in accordance with current Building Regulations and the details shown on Drawing Ref Cavity Wall Section. Where advised by the structural engineer the floor slab shall be reinforced with suitable mesh reinforcement and waterproof concrete used along with a 1000/1500 micron DPM with sealed laps. 

4.2.2. In some ground conditions and where flooding over 900mm is anticipated it may be necessary to strengthen the walls and fit an under floor system to reduce hydrostatic pressure under the floor construction.

4.2.3 The external face of the cavity wall below ground from the foundation up to ground level is to be treated with an impervious barrier or membrane in accordance with the manufacturers recommendations (Flodef Membrane or similar). Any drains or services entering the building are to be properly sleeved as recommended by the manufacturer. A minimum void 500mm wide down to the top of the foundation shall be left for the system to be fitted by FLODEF Installations Ltd.  Once the system has been fitted the void should be backfilled up to ground level, allowing for hard or soft finishes, with min. 20N pumped concrete with maximum 10mm aggregate with an approved waterproof additive mixed in accordance with the manufacturers recommendations.  The concrete is to be fully vibrated and care must be taken to ensure the system is not disturbed or damaged by the backfilling or vibrating operations. When placing the concrete it is imperative that the internal box temporary spacers are kept in place until the concrete has completed its initial set and has preferably cured.

4.2.4. It is recommended that the system is fitted after the scaffolding has been taken down around the building.  If the builder requests that the system is fitted at an earlier stage of construction then he shall take all adequate precautions to protect the system from any damage.

4.3. Retrofit Systems

4.3.1 The construction needs to have been carried out in accordance with the details shown on Drawing Ref  Cavity Wall Section or similar.

4.3.2 In some ground conditions and construction types and where flooding over 900mm is anticipated it may be necessary to strengthen the walls and fit an under floor system to reduce hydrostatic pressure under the floor construction.

4.3.3 The external face of the cavity wall below ground from the foundation up to ground level is to be exposed, cleaned and treated with an impervious barrier in accordance with the manufacturers recommendations. A minimum void 500mm wide down to the top of the foundation shall be excavated for the system to be fitted. 

Once the system has been fitted the void should be backfilled up to ground level, allowing for hard or soft finishes, with min. 20N pumped concrete with maximum 10mm aggregate with an approved waterproof additive mixed in accordance with the manufacturers recommendations.   The concrete is to be fully vibrated and care must be taken to ensure the system is not disturbed or damaged by the backfilling or vibrating operations. When placing the concrete it is imperative that the internal box temporary spacers are kept in place until the concrete has completed its initial set and has preferably cured.

4.3.4. It is recommended that the box housings of the system is fully fitted before backfilling is commenced. However in some ground or weather conditions the system may be fitted in sections with the concrete keyed by scabbling off between pours if it is left for 24 hrs or more between pouring the concrete.

4.3.5. Where trafficking is heavy, i.e. garage doorways etc the system is set down and a special cover frame and plate positioned to accommodate light vehicular traffic passing over the system.  When deploying this cover plate will need to be removed before deploying the system.

5.0       Above Ground System

5.1 The deployment instructions go through the simple deployment of the system.

5.2 Uprights are fixed to the main structure comprising the seal housings and back plates, which are used to form external and internal angles. Running joints are formed with a back plate and seal housings between each section of the system.

5.3 When deployed the membrane is raised from the housing by pulling up the top rail which is held in place by retaining latches at the required maximum design height whilst the side seals are then inflated to the specified air pressure.

5.4 The sink waste gully will be repositioned and a removable section fitted to the waste pipe and a cap supplied to be fitted before the system is deployed.

5.5 Similarly low level tumble dryer vent pipes will be adapted to take account of the Flodef system and where floor standing boiler vents are present adequate precautions must be taken when fitting the system.

5.6 In accordance with BS PAS 1188 – 3 you will be provided with ply panels to place over large glazed openings and door openings where required to support the membrane when deployed.

6.0 Key Materials Specification (N.B. main parts suppliers are all approved) Available on request.

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