cr06-07 frp swimming pools

NGCC/NCN Case Review 07/06: FRP Swimming Pools e-mail: [email protected] Web: www.ngcc.org.uk

Case Review 07/06 FRP Swimming Pools.

Introduction

Domestic swimming pools are big business in the USA and Australia. It is estimated that the US pool and spa industry is worth $8 billion alone. However, FRP swimming pools account for only 3% of this, despite offering distinct social, economic and environmental advantages over the concrete and vinyl liner pools that dominate the market.

The FRP shell structures have now overcome blistering problems encountered on their introduction, thanks to the development of vinyl ester resins. At present this application is pertinent in those countries with warmer year round climates. However, the economic benefits offered by FRP pools could help expand the market in other countries, particularly the UK.

The sports industry has also taken advantage of the property and construction benefits offered by FRPs. A recent high profile example is the Sydney Olympic training pool, situated in Homebush, Australia. The pool harbours the largest fully removable FRP floor in the world.

The application is a good example of synergy combining 22 tonnes of FRP with 30 tonnes of corrosion resistant metal. The use of FRP made installation possible in 8 months, at an average cost of $1750/m2 compared to $3000/m2 previously. The lighter weight of the floor allows it to be raised or lowered (range 2.5m to zero) to cater for a range of activities, thus increasing the functionality and appeal of the pool.


Key properties The higher strength/stiffness to weight ratio of FRP materials means that less material is

required in the structure, and provides greater impact resistance as a result of these properties.

Vinyl-liner pools are prone to cuts and other damage. The FRP shells can be pre-fabricated, minimising site assembly and installation times. The flexibility of composites allows the design and manufacture of almost any shape. A standard product range can be developed, maximising the efficiency of the

ordering/delivery/installation process The shell construction method provides an opportunity for synergy with other materials to

achieve desirable functional properties. For example, the addition of a ceramic core provides greater stiffness and thermal insulation.

The shell can be completely finished and quality controlled before delivery. Through life costs are significantly less than for conventional pools due to a number of

contributory factors: o Site installation is typically 1-5 days, compared to 4-8 weeks for a concrete or liner

pool o The light weight reduces personnel and site equipment requirements during

installation o No periodic maintenance/re-painting is necessary o Power consumption is less due to better thermal properties. o It is claimed that they require fewer water treatment chemicals than conventional

pools due to less microbial contamination. FRP shells can be sold direct to the homeowner for D-I-Y installation. Electrical and chemical usage is about half that of a concrete or liner pool, meaning

extraction and processing benefits for the environment. There is no leaching of chemicals from the shell into the surrounding earth. Rapid installation causes minimal disruption to the domestic routine. Pools can be manufactured to the specification of the customer. The pool can be moved to a new place of residence. The pools can be installed all year round, unlike gunite pools which cannot be installed in

cold weather. FRP shell pools are the least dependent of all pool types on the skills of the installation

crew.

Opportunities for FRP and potential market size

This is a predominantly market driven leisure product. Less significance is placed on the structural performance as would be in industrial applications. Therefore there is little 'pure' research behind the products, manufacturers have taken up the use of FRPs because of their production benefits, long term durability and negligible maintenance requirements. The leisure industry has taken a lead from the marine and offshore industries, where FRPs have been proven to provide high performance in aqueous and corrosive environments. Long term cost effectiveness is the major driver for this domestic product.

The main competitors for FRP pools are gunite (concrete) and vinyl liners. A comparison of key characteristics can be made:


FRP Pools

Concrete (Gunite) Pools

Vinyl Liner Pools

Warranty

Lifetime by the Manufacturer

1-5 years by contractor

Liner seams only

Installation Time

5-13 days, ready for decking using few (if any) subcontractors.

8-12 weeks using many different subcontractors.

2-3 weeks using few subcontractors.

Shapes of Pools

Limited to the models of the manufacturer.

Unlimited

Limited to the models of the manufacturer.

Price of Pools

Average

High

Average

Estimated Chemical

Usage

Surface does not alter water's chemical

balance. Substantially fewer chemicals used.

Plaster reacts with water to raise pH levels. Uses substantially more acid

& chlorine to counterbalance this chemical reaction.

Surface does not alter waters' chemical balance.

Substantially fewer chemicals used.

Estimated Electricity Use

Circulate Water 4-6 hours daily.



Surface Texture

Smooth, non-abrasive to skin or swim suits,

walking and seating areas are textured for

slip resistance.

Rough, causes skin abrasions to feet, hands

and swim wear.

Slippery, easily punctured or torn by toys, pets, or

surfacing rocks.

Algae Penetration

Algae sweeps off with wall brush.

Algae grows and is harbored in pores of

gunite. Acid baths and scrubbing required to

remove algae.

Seams of liner harbor algae.

Estimated Maintenance

Time

1/2 hour per week maximum

4-5 hours per week

2-3 hours per week

Major Renovation

None

Re-marcite or re-plaster at 5-7 years.

Vinyl Liner needs to be replaced every 7- 9 years.

Quality Control

Manufactured in controlled factory to

quality control standards.

Manufactured on-site. No environmental

control.

Kit manufactured in factory. Quality of on-site

assembly varies by installer.


Installation of FRP pool

Flexible design As well as small domestic pools, FRP materials are used for many applications in large public and competition swimming pools, such as starting blocks, end walls, water polo goals etc. The application of FRPs offers greater flexibility in the use of the pool than would be achievable using other materials. Two important features are moveable bulkheads and moveable floors these allow the pool size to be tailored to meet varying requirements of its use.

Moveable bulkhead The moveable bulkhead is designed to function as a substantial stable pool divider which can be fitted with starting blocks and used for national and international level competitions. The bulkhead spans the width of the pool and allows the pool to be programmed for maximum utilisation and revenue generation.

The motorisation option comprises battery powered transport trolleys which can be stored away from the pool. This system eliminates the hazards of wiring built into the bulkhead.

Bulkheads are built using a unique modular component system which ensures high standards of engineering and allows for the detailed customisation to meet the needs of each installation. This means that tolerances can be exceedingly fine while costs are kept under control.

Moveable floor The Variopool system is based on a floating floor which is pulled to the desired depth using a pulley system of stainless steel cables and hydraulic cylinders. This is a proven concept that is characterised by its simplicity and a minimum of moving parts resulting in high reliability and low maintenance costs. Moreover, a unique feature is that it is unnecessary to empty the pool for regular maintenance or repair.

Movable pool floors can be made from various materials or combinations of materials. The choice of material is determined by the customer, the set requirements and the functionality. Variopool supplies three different types of floor: - Glass-fibre reinforced plastic - Stainless steel frame covered with glass-fibre reinforced polyester - Stainless steel frame covered with polypropylene panels.


All three types have an anti-slip surface as described in the latest version of NEN 13451-11.

A GRP floor consists of elements between 9 and 15 metres long and 2 to 2.5 metres wide. The buoyancy is guaranteed as it is permanently integrated into the elements. When making these elements, at an early stage an indication must be given of whether the movable floor must have competition lines, coloured areas or logos. The advantage of this is that they do not wear.

Photos courtesy of Variopool

The advantage of the glass-fibre reinforced floor is that it is completely self supporting, the mould imparts an anti-slip structure to the floor surface and the floor can be installed very quickly, meaning that the swimming pool only needs to be closed for a limited time.

The stainless steel frame with GRP panels moveable floor is built using a 316L stainless steel frame that is joined together using nuts and bolts. Glass-fibre reinforced anti-slip plastic panels are attached to the frame.

The advantage of this type of floor is that the parts can be brought in through a small access opening. The parts of the structure are also light, meaning that there is no need for hoists or other tools.

Future developments

It is inevitable that manufacturers will start adding FRP pools to their product portfolios as consumers become aware of their functional benefits and economic savings. The products will become more readily available and cheaper as manufacturing systems develop.

Internet ordering of 'standard' pools is already available and will become a large market over the next 5-10 years as the concept filters from the main markets in the US and Australia. The ability for self installation will also attract a wider market due to associated financial savings.


There is the potential for development of indoor FRP pools in the UK. A total FRP 'system', including covering structure, would reduce costs and promote the product to a wider market.

Further information

Companies

Variopool B.V., Netherlands http://www.variopool.nl

Oasis Swimming Pools - California - Advanced Composite Pool (ACP) www.deluxepool.com/acp.html

Advanced Composite Technology Company Ltd - Australia www.adcomp.comp.au

Antiwave - FRP pool components www.dibro.co.nz/antiwave http://www.anti.to/Pdf/BWBrochure.pdf

Research Papers "FRP swimming pools' low maintenance, high quality make a splash". Feature in "Composites Technology Magazine", July/August 2001.

Acknowledgements Acknowledgement is given to the NGCC steering group for their valuable contributions to the document.

Disclaimer: Whilst NGCC has endeavoured to ensure the information in this document is accurate, NGCC makes no warranties or guarantees, actual or implied, and bears no responsibility for the use of information from this document. NGCC cannot accept any liability for any loss or damage, whether direct, indirect or economic, as a result of the use of information in this document.

cr06-07 frp swimming pools

Documents