HARD LANDSCAPING
Corten effect GRP planters have been used due to the material being lighter than steel while having a realistic resemblance to Corten Steel. GRP Corten effect replicates Corten steel without the associated complication of staining and the weight of the Corten Steel. This effect was also chosen to match the Corten wood stove owned by the client. Europlanters were selected to installed the majority of the planters due to them being a local supplier to the location of the site. We tried to use local suppliers where appropriate to reduce the carbon footprint of the construction.
Planters were installed to allow for drainage by sitting the planters on a Millboard sub frame. This technique allows for any excess water run off to flow away from the planter and into the drainage system on the roof terrace. Thus improving drainage for the planting throughout the year.
A contemporary glass balustrade installed allows views from the terrace onto the surrounding countryside. Stainless steel handrail and glass panels tie into the contemporary design.
GRP partitions supplied by Europlanters are also lightweight and provide screening to create the feel of enclosure within the terraced garden. The gaps within these screens allow glimpses onto the existing native trees that provide a contrasting backdrop to the Corten effect screens.
SOFT LANDSCAPING
We feel that the colour palette used within the planting and the materials selected is a success and provides an engaging scheme that is allowing nature to thrive. Multi stem Amelanchier underplanted with sensory plants such as Salvia officinalis and Stachys byzantina surrounding the pergola offer seasonal interest, scent, texture and colour to engage with users of the space.
Rain water harvesting systems were installed by initially excavating the ground at a position between the surface water outlet pipe and the end of the garage with an outflow connecting to the existing soak-a-way system. We installed a rainwater harvest tank with 7500 litres capacity of water which was buried to the manufacturer’s specification. This is located within the upper area of the play lawn area following the line of the existing surface water drain system. A standard outdoor tap is positioned on the end of the garage wall connected to the unit with MDPE pipe buried underground from the unit for the water supply to allow for watering.
MATERIALS SELECTED AND WHY
We constructed a mitred picture frame deck board around the perimeter of the pergola base which helped to frame the pergola structure. A Subframe was constructed from Plas-Pro terrace joist battens 2400x50x50mm screwed together and suspended on adjustable joist cradles. The deck boards were Millboard with enhanced grain texture, brushed Basalt 3600x176x32mm. These boards were affixed using Durafix trimhead stainless steel screws 4.5x60mm. These screws were subtle and blended into the decking boards which compliments the design. The Plas-Pro sub frame material was chosen due to the materials longevity and also as it is made from 100% recyclable plastic.
Caribbean Blinds supplied the pergola structure with rotating roof louvres, L.E.D warm white perimeter lighting and integral heater. A Halogen element within the heater heats the body and not the air wasting less energy than conventional heaters.
Visqueen damp proof Eco Membrane has been installed underneath the millboard decking on the slightly sloped roof to ensure that water did not damage the roof structure in future. We installed Polished Dark Pebbles to provide contrast to the colour of the Millboard decking. The planting bed includes a weed proof membrane beneath the cobbles. This was to improve drainage and allow the plants to thrive.
Selected porcelain paving was supplied by London Stone, Blue Grey Granite Plank 900x200mm. Paving is laid on a concrete raft 100mm in depth Concrete to be laid on a sandwich of Butyl liner and fleece protects the integrity of the roof material. The Blue grey Granite plank paving compliments the millboard and also provides a contrast to the GRP Corten steel planters and screens.
LOGISTIC CHALLENGES AND OVERCOMING THEM
During construction the glass panels to the balustrade were left down to allow access for bringing in heavy materials and large design elements. This allowed us to safely access the raised terrace and was successfully achieved. Moving materials in this manner meant that we could bring the materials into the site with ease and avoided having to use the restricted access to the rear of the property. We worked closely with the client to achieve their dream garden and endeavoured to work at appropriate times to suit their lifestyle.
OTHER CHALLENGES
One of the large planters had sunk in the corner of the garden so we installed stone paving to displace the weight of the planter. This helped to keep the planter in the required position without damaging the membrane underneath. There was a malfunction in the pergola mechanism and this was replaced and re installed to the suppliers operational and maintenance instructions.
Resetting some of the Millboard decking boards that had moved since they were initially installed. This was carried out to ensure that they lined up correctly. The timber seating bench was adjusted to the required height to line up with the GRP Corten effect planters. This included tightening the bolts on the planters to ensure they were tightly fixed.
During installation of the decorative screens two tiles were damaged accidently. These were replaced and refitted accordingly. Some of the decorative panels were misaligned so we addressed this by using in fill pieces to line up the panels with precision. We resolved this and made a positive impact on the scheme.
Further remedial works were undertaken to the external staircase leading up to the roof terrace. A millboard step section was required to link to the metal staircase.
SUMMARY OF FINISHED PROJECT
We feel that the finished project is a success as it follows the clients brief and provides a high quality contemporary terrace garden. There have been some challenges highlighted in the wording above but we endeavoured to overcome these to deliver an excellent garden using sustainable methods of construction. Also we feel that the use of high quality materials and respected local suppliers where possible we have achieved a design that will last the test of time.
The finished terrace garden has been constructed closely with the client to provide a space to be enjoyed for many years to come.
Using design elements to create a functional roof terrace has been a success and provides the client with an engaging space for relaxation and also entertaining. The softening of the hard landscaping with the planting compliments each other and the sensory plants within the raised planters offer seasonal texture and interest which will benefit the family for years to come.
Furthermore lighting has also been utilised to highlight features and also allow the client to enjoy the garden all year round.
ADDITIONAL INFORMATION
Appropriate irrigation to the roof terrace was essential and various measures were taken to ensure water run off and irrigation was successful and functioning properly. A trench was dug to connect from end of garage around the rear of garage and we positioned a MDPE water pipe to link up to the roof terrace on the outside wall. Installation of an exposed pipe covered with insulation foam tube was required also.
A single tap was fitted for the client to use and was positioned on the end of the garage wall on the terrace. While a T junction off pipe was installed to supply irrigation pipework with an isolating tap. The irrigation system controls 6 areas; solenoid valves control each supply allowing for each area to be controlled for different amounts of water as and when required by the client. This allows the client to manage their irrigation system from their mobile device or web browser which was a benefit to the client. Each area has micro sprinklers to cover each planter to ensure correct and proper irrigation throughout the year. There is also pipework positioned under the Millboard decking which rise within planters where possible to ensure improved irrigation. An electrical supply of 240v was required for the control unit for connection by the site electrician which was organised and installed.
