Alternative Pool Tank Types
I. CONCRETE POOLS
Introduction
There is no doubt that the structure of a swimming pool built in reinforced concrete will have a very long life before it deteriorates to the point where it is unusable.
Until the advent of vinyl liners, concrete pools were finished with masonry paint, fibre-glass, acrylic paint, river pebbles, glass beads, aggregates and all kinds of different plasters/renders and of course, tiling. Tiling was carried out initially using large pattern tiles that require really specialised tilers. Mosaic tiles in large sheets are now predominantly used because they are much quicker and easier to fix although they can cost 10 x as much.
Nowadays, reinforced concrete pools with vinyl liners dominate the European quality pool market and monopools (made of fibreglass) the smaller basic pool markets.
The vast majority of outdoor pools in the UK are and have been built using concrete in one form or another. They are far more acceptable to the average house buyer, and as a consequence the type of pool tank will have a direct effect on the value of the property in which they are built.
Tiled Concrete Pools
A modern tiled pool relies on the 4 component systems that are required to ensure that the tiling does not need to be replaced within a very short timescale and that the pool does not leak.
Water-proof render (1st Component) is needed to provide a stable flat sub-base on which the tiles are glued using the a special adhesive (2nd Component). It is vital that tiled pools are grouted with an epoxy grout (3rd Component) as cement grouts will fail and need replacing in a few years. Finally, the tiles themselves (4th Component). Small mosaic tiles supplied as sheets are not difficult to install and cost around £50 per square metre. Larger tiles can be a lot cheaper but are very difficult to install on large flat areas like pool walls.
The primary problem with tiling is that these 4 Components are all provided by different manufacturers and each one needs to be used "exactly as it says on the tin". As a result, the pool buyer does not have an overall guarantee on the completed system. Many people end up badly out of pocket because they have to foot the bill for retiling themselves - which is a common occurence.
Most tiled pools are built using Gunnite or Shotcrete (as described below). This is quite a costly process because of the need for highly skilled labour and large scale pumping equipment.
Tiled pools can also be built using concrete blocks but these often fail structurally because they have not been designed by a qualified structural engineer. Timber shutter systems are also occasionally used for concrete pools. Both blocks and shuttered pools are costly because of the skilled labour required and the long construction periods.
Vinyl Liner Concrete Pools
A vinyl liner pool relies on the liner to provide the waterproofing and because the liner will easily stretch over any cracks the concrete can be designed to BS110 or the European standard equivalent. The same volume of concrete is required but a lot less reinforcement will be needed - making the walls much easier and quicker to build.
Method of Construction
Concrete pool tanks are currently built using the following methods:
1) Reinforced concrete walls formed using shotcrete or gunite
Shotcrete is formed by taking very wet concrete from a truck mixer to an application gun where compressed air is used to "fire" the concrete at a timber form that is placed behind the reinforcement.
Gunite is similar but sand, cement and water are mixed together at the gun and fired at the timber forms. Normally Shotecrete is used because it is cheaper if there is a local ready mixed concrete plant.
There are only a few UK firms geared up to do this and the costs are high because the same companies work for the government on various large civil engineering projects. Very specialised equipment and very skilled labour is also required.
2) Concrete Block Walls with reinforcement
Historically this was the most common type of construction but it has fallen out of favour recently because of the labour costs and the necessity to render the walls. Transporting and laying the very heavy blocks and the rendering are time consuming and costly processes.
3) Reinforced concrete walls using timber shuttering systems
This involves the temporary installation of heavy reinforced plywood panels or steel forms that retain the wet concrete until it cures and gains strength.
The walls need to be designed by a Chartered Structural Engineer according to the water retaining Codes of Practice and the large amount of reinforcement required makes the structure difficult to build and very costly.
The main problem with all three of the above methods is that they require costly specialist equipment and even more costly skilled operatives.
That is why Bluepools always uses "Polybloks".
II. MONOPOOLS
Monopools are delivered to the site as one piece and are then craned into the excavation. Some are provided with all the pipework but some are delivered as shells and the pipework has to be fitted on site.
Fibreglass
High quality fibreglass pools that are provided with manufacturers' guarantees can be a practical solution in some circumstances. Some are sold as kits for self-builders / DIY (e.g. Bakewell pools) and some are sold on a supply and install basis (e.g. Compass Pools). Most are manufactured in Eastern Europe where the labour costs are lower. All the better quality fibreglass monopools are made indoors in an environmentally controlled environment and should last at least 10 years.
Niveko Polystone
Niveko pools are fabricated from a 10mm sheet of High Density Polyurethane, a resin that is mixed with powdered stone additives (manufactured by a company called Polystone) that are welded together by a machine and hand welding on the more complicated joints. They are much more vulnerable to damage in transit than one piece ceramic or fibreglass monopools and the surface can easily be scratched because it is not as durable as the gel coat provided on good quality monopools.
Niveko provides a 10 year guarantee that the pool body will remain watertight but this only guarantees that they will repair the pool - and it will need to be empty, clean and with external access to the damaged part - not really much us if the pool is in the ground and surrounded with concrete to stop it from floating like a boat. The Niveko guarantee does not mention colour change or deterioration in the gel coat. The guarantee is also based on Czech law and if you sue them the documents need to be in Czech and action will presumably need to be taken in Czech courts.
Norsup Ceramic and Fibreglass Pools
Some of the best ceramic and fibreglass pools available are manufactured by Norsup. This is a brand owned and marketed by Bosta - a large company in Holland. The Norsup range has a 15 guarantee on construction and 7 years against osmosis. It also has a gel-coat that is designed to resist the UV radiation that eventually will destroy all fibre-glass pools. The smaller Norsup pools are much better value for money than comparable Niveko pools and and basically have the backing of the large Bosta group of companies with substantial presence in the UK and so are much safer to buy.
Monopool Defects
Poor quality fibreglass pools can be covered in black spots where the gel coat has failed with a few years after installation. They are never used for indoor pools because the high capital cost of the pool hall and equipment justifies the installation of a long lasting pool tank.
Because of the potentially short life of a fibre-glass pool they can have a negative effect on the value of any property where they have been installed. This problem is exacerbated if the pool has been surrounded by concrete to stop it from floating - the removal of 20 or 30 tons of concrete can be very expensive!
Why Bluepools does not supply Monopools
The cost of manufacture, transport and installation of premium quality fibreglass pools results in a situation where they cost more than vinyl liner pools built in Polybloks.
There is a also significant risk of structural damage during transport and installation.
Furthermmore it is impossible to renovate the surface of the gel coat of a fibreglass pool and vinyl liners cannot be fitted to them for renovation purposes.
III. PANEL POOLS
The introduction of vinyl liners transformed the pool industry because it allowed manufacturers to produce panel pool kits that could be fixed together and then waterproofed with a vinyl liner.
There are literally hundreds of different types of panel pool kits available across Europe and they are all a complete waste of money.
They are aimed at the DIY market but are useless because in the majority of cases they are more difficult to install properly than a concrete pool.
They all share one unique drawback - none of them are founded on a reinforced concrete footing that holds the walls rigidly in position.
As a result, if a panel pool ever has to be emptied it is likely that the walls will move or even collapse! They are never used for an indoor pool for the same reason as fibreglass pools.
Furthermore, the water circulation systems are never of the level required to keep the water safe in a hot August period and do not approach "Clear Clean Water" standards.
They will all detract from the value of any property and can be very costly to remove.
IV. WOODEN POOL KITS
Vinyl liners also allowed the introduction of wooden pools and other above ground pool types.
Top quality wooden pool kits that incorporate a reinforced concrete base slab are very good value for money and can be installed either above ground, part in-ground or wholly inground.
The best range of timber pools is a range called Gardipool. They are good quality and are sold by several UK suppliers.
The pool will probably not effect the property value significantly unless it has been sunk ino the ground.
V. STAINLESS STEEL POOLS
Stainless steel tanks are a very expensive solution. The specialist suppliers also add ridiculous profit margins that are never justified. If a stainless steel finish is required the best way to do it is to use stainless steel panels on the face of a reinforced concrete tank.
They can have a negative or positive effect on property value and this will depend on how visually attractive the pool is.