The Water Gardens – Makers & Triflex
The Water Gardens
The Watergardens incorporating Burwood Place Basement car park was designed by award winning architects Trehearne, Norman, Preston & Partners and was constructed by Wates. The original construction consisted of 3 12 storey residential blocks, 2 podium decks, a 202-space basement car park and the Watergardens designed by Philip Hicks, Landscape Designer.
The construction took place between 1961 completing in 1966. The main structural form was reinforced concrete which provided the structural fabric for both the car park and gardens and a combination of reinforced concrete to the towers with mosaic tiling and associated precast units.
Originally constructed for the Burwood Place Development Company, a subsidiary of the Church Commission, this housing project provided 1200 dwellings for residential use built in what is described as ‘Brutalist or Modernist Style” using monolithic structures with rectangular features a result of conflict and pressure between cost, form and functionality.
The operation of the original Covent Garden site had become cramped, archaic and unsuitable given the increase in motorised traffic. After several feasibility studies several new sites were considered but the market was moved to Nine Elms due to cost and location.
As with most schemes built within the 1960‘s the construction methods were traditional and the technologies available were limited in constructing and protecting the fabric.
The basement car park beneath the Watergardens has almost incurred leaks and water penetrations from the outset but with the continued deterioration of the structural fabric and significantly reduced occupation of the car park with more attractive premises being available the NCP lease ended in January 2017 and the car park became redundant and closed to the general public.
The structural covering some 5800 m2 had been left to its own devices since its construction in 1966 with periodic measures to placate the water leakage through the structure which was causing damage to parked vehicles and moreover the structure itself.
The existing pools had been leaking into the structure since its completion in 1966 containing over 148,000 litres of water and after the last time the pools were maintained serious amount of silt mud and debris had accumulated.
The aqua beds had become so overgrown that the pool construction was lost and damage was being caused to the Philip Hick design, and the 9 individual planters constructed to form the oriental feel garden had become lost in the overgrown trees and species that had been added to over time by residents.
What was intended to be an ornamental garden with simplistic lines and features had in fact turned into a jungle losing the shape and dynamics of the garden and proving difficult to manage. The competition for space meant that plants had become diseased and were dying.
The overall parking environment had become so poor that less than 8% of the parking capacity was being used with a peak of 66 cars occupation from the 202 available.
In order for the car park to become a storage facility it had some major challenges to overcome.
1.the roof structure was incomplete with ventilations voids that need to be infilled with proposed Green Roof systems.
2.the structure was leaking and allowing in water to penetrate the structure, 5800m2 of surface area
3.the internal fabric needed to be repaired
4.the lighting system within the car park was not complete and was adopted from the 1960’s
5.asbestos was known to be in the storage and electrical cupboards
6.the existing drainage system did not work with roof penetrations disposing water on parking deck slab
7.the floor slab needed repairing and the whole internal environment a complete uplift
8.the drainage valves to the pool had seized
9.a fire corridor had been constructed and existing fire sprinkler system over hauled to provide protected access.
Due to the asymmetric nature of the design of the gardens access to the planters was critical in so much that these areas had to be completed together with their respective planting as access was required across the pools when transporting large trees and soil. As heavy plant was needed these areas had to be completed to avoid any damage to the waterproof membranes.
This provided a sequence whereby the planters were first attacked followed by working from the top of the site to the bottom picking up pedestrian areas and pools as we came through the site taking care not to travel or articulate any machinery of the new finishes or waterproofing.
The pools had to be drained but due to the seized drain the pool only drained from a single point so the 4 pools could not be drained individually. To overcome this MAKERS cored through each pool base and transferred the water through a series of hose pipes directly into the basement storm system
Due to special features of the Philip Hicks design the concrete planters had to be protected to ensure the concrete fluting created from the original pouring process was not damaged as a result of removing both vegetation and soil. Due to the difference is size of the planters some were hand dug out and other a combination of small mechanical diggers and dumpers.
The design of the planters created a structure 1.60m high off the original roof slab construction resulting in over 526 tonnes of soil and vegetation being removed off site, not an easy task to complete on a site as restricted as this one.
It has been over 50 years since the pools were last drained and the volume of spoil created by the debris, silt and aquatic sludge meant that 208 grab movements were required to remove off site to get back to the original concrete. With only one access road available the visits had to be planned and coordinated as the only access route was a single lane road traversing the perimeter of the site. Access and egress were controlled by gated entry.
Makers selected Triflex as waterproofing material manufacturer, Triflex are a leading European specialist in the manufacture of cold liquid applied waterproofing, surfacing, protection, marking and repair systems.
Repairs to the concrete were carried out using Triflexs repair system with the entire area then being coated with a double Triflex Pro-Tect system.
The main benefits of the Triflex system: Versatility and compatibility, Cold applied, fast curing with rapid installation , Single process application, Self-terminating, Fully reinforced technology Tough and durable protection.
With the basement car park below being transformed into a storage facility Makers had to ensure that the entire 5800m2 area of the Water Gardens would be leak free. After removal of all soil and vegetation from the insides of the Planters and tons of silt and mud removed from the ponds, which was approximately half of the entire area the area was cleaned by high pressure washing to allow close inspection of the concrete and any repairs that needed to be carried out before application of the waterproof membrane. Any concrete repairs required were carried out with Triflex Repair materials – Triflex Cryl Paste Mortar, Triflex ProFloor and Triflex Cryl RS 240 in line with the specification.
Weather was a real issue in the waterproofing element of this project as continuous heavy rain fall caused delays due to many hours in the mornings spent extracting the water with wetvacs so water proofing could continue. Due to the efficiency of the Makers workforce this lost time was pulled back.
Once the repairs were completed the areas were waterproofed using the Triflex reinforced Pro Tect and Pro Detail systems. Previously sealed day joints were raked out and replaced with Triflex Flex filler and reinforced before applying the fully reinforced waterproofing. Because of the importance of providing a leak free finish and huge issues it would cause if the system was ever breached Makers doubled up the system, Base coat, fleece, top coat, once this had cured the same process was carried out to provide an exceptionally strong membrane. Triflex’s Technical Department would visit site monthly to inspect and sign off works that had been completed.
To protect the waterproofing from puncturing in the planter areas through garden maintenance ‘no dig” Corex board was introduced to the base and walls of the planters. Holes were drilled through the planter walls to allow drainage into the ponds.
The planters were refilled using 100 mm deep 10mm aggregate to provide drainage, 300mm of 40mm gravel, 600mm of sand sub-base, and 450mm to TOHA approved topsoil topped off with 50mm mulch.
The voids would be home to a strategic Low height planting strategy green roof. As part of the Planning Consent the planting had to replicate the original form and structure of the void so the use of grasses and low maintenance plants was critical in creating this look.
As the voids were a new construction the design was to be lightweight, capable of supporting the roof but strong enough to allow the formation of a Green Roof. Above the no dig board, 500mm of polystyrene was placed to lift the infill height and reduce imposed load. Terram matting was placed over the polystyrene and then a special ZINCO Reservoir material was added. The Zinco material has the ability to also be lightweight and was made up from crushed volcanic rock and crushed brick medium.
Metal deck formers were placed level with the existing soffit and flexible joints created to the perimeter. Once in place the concrete slab was poured 150mm thick in C35 concrete. Once fully cured these areas were then waterproofed with the Triflex System.
Holes were drilled through the void walls to feed the water harvester system. Triflex reinforced waterproofing was applied to the surfaces and then protected with Cordex “no dig”resistant board.
The voids in the Watergardens provided both ventilation and natural light to the basement car park. The metal rails were grit blasted and painted. These were retained to provide a baseline to the original void openings and to maintain elements of the original construction to comply with the Planning Consent conditions.
The Green roofs would be supplied with water from the irrigation system created below the pedestrian paving. New pump housing ensure adequate water is provided from the harvester units filled during rainfall. The capacity of the harvesters is a massive 95,000 litres.
As the areas were completed the new tress and plants could be planted. The mix of planting will add colour all year round and provide a cleaner look to re-establish the original form & feel of the oriental flavour that Philip Hicks originally intended. There are over 25 Specimen Trees, 2000 plants and 6000 bulbs contained within the planters, Green Roof voids and aquatic beds, not including the 12 Olive trees in planters that were retained.
The garden was difficult for tenants with mobility issues and had no disabled access a reflection of the original construction of the ’60’s. To make the garden space more accessible 2 access ramps and a new set of stairs were constructed to allow mothers with prams and mobility scooters to gain access. High quality finishes were installed to comply with current regulations. The gentle incline removes the need for handrails maintaining the minimalist design
The car park has been reinvented with the closed car transformed into a brand new storage facility that serves the local community.
The concrete structure has been repaired and waterproofed and guaranteed for the next 20 years.
The Watergardens have been returned and transformed back to the original design Marking the 150 year anniversary of the Hyde Park Estate.
5 new green roof have been constructed to improving the air quality in the area
Disability access has been constructed to allow all the tenants at the Watergardens to enjoy the facility.
The fire sprinkler system is now working and fully operational
95,000 litres water harvesting reservoir has been created to maintain the gardens and pool levels.
The garden has been transformed with a completely inclusive design that will last another 50 years with architectural features.
Created a community nature project for the Hampden Gurney School with site visits and competitions
Improved the health of the fish who are now reintroduced back to their pools and improved the water quality and management. As part of the structural repair works the water within the pools some 148,000 litres of water had to be drained but due to the pool drainage system it had to systematically pumped out of the pools and fed into the storm drainage via the voids into the basement car park. This was done in 2 operations so that the fish could easily be removed and prevent overloading of the existing drainage system.
Children from 3 classes were invited to site to see the is be extracted and to start their “pondlife” school projects.
Over 70 pupils attended with teachers, teaching assistants and Mums and Dad’s. They also met a very special person who was engaged to prevent any birds nesting in the trees as these were due to be removed.
BUDDY the harris hawk was on site to meet the children and his handler Oliver allowed the children to stroke him and answer questions. Buddy trained from a chick is 3 years old and was a clear favourite with both Children and Adults.
“..my favourite thing was the Hawk, I enjoyed stroking him, he was so soft.” James pupil Hamden Gurney
The children took great joy in watching the fish be carefully removed form the pools by Ian Owen of Aqua joy fishery specialists who were going to be housing the fish for the duration of the project until their return. The larger fish brought squeals of delight from the children and a total of 285 were removed including Mirror and Koi carp together with Golden Orfe.
As part of MAKERS “BE SAFE BE SEEN “ campaign the children returned to class to begin their projects and enter a picture into the competition. 2 boys and 2 Girls would be selected from each class and prizes awarded to those lucky winners who captured the essence of the day!
“we set up holding tanks so the children could watch the fish but the real star turned out to be Buddy! he was so good with them considering how many children actually stroked him.. the only person he bit was me but the kids were truly amazing.” Willy McCrimmon Regional Contracts Manager.
“ the feedback from the children has been awesome and they were excited throughout the whole day. I would like to thank willy and his team for their efforts and generosity on the day, I have forwarded a few comments from the children” Robbie Middleton Teacher Hampden Gurney COE.
“ I liked the animals and the hawk’ Philip, “I liked the big Fish!!!” Estelle, “I liked the little fish because they splashed when they were put into the big pool” Alexis
Following their visit to the water gardens in June Simon Lamb managing Director returned to the school to present prizes to those children who in the opinion of the teachers had achieved the most with their colouring and story behind the pictures.
Winners were invited to the front to their classes to explain the picture and what they enjoyed most about the day. 2 boys and 2 girls from each class were presented with reading books by Juila Donaldson author of the Gruffalo and Hugless Douglas as well as David Melling another childrens favourite author. Winners also received MAKERS Lifecare Satchels and Colouring Pens.
All the children that attended received Makers Pencil cases complete with colouring pencils, rubber and ruler to ensure they continue with their artistic tendencies.
of the intermediate decks, but a concrete block coping stone had bee installed as part of the original design. The mortar beds between the concrete blocks had been eroded over time and the blocks had become loose. These concrete blocks were used to increase the height of the parapet walls to a permissible height. The blocks provided
The competition winners returned to Watergardens to take part in the restocking of the pools. The fish had been accommodated off site and were excited to see them re-introduced under the watchful eye of fish specialist Ian Owen of Aquajoy.
Over 60 sixty fish were introduced in the first batch covering 6 species that were originally removed from the pools. The larger fish were first a climatized and the smaller fish placed in the water by the pupils via small fishing nets, each taking time to name the fish individually.
the competition winners brought along their winning entries and were amazed to see their pictures transferred onto big banners that had adorned the site for the duration of the project bringing colour and a sense of community to the project. the children were joined by Staff and Governors of the school to watch proceedings and learn about the fish