Published: February, 2019
When you have an aspiration for a fabulous development with beautiful outdoor space, you want to make sure it is implemented to your vision. As you embark on a project that demands outdoor space, such as a roof terrace, it's important to align the practical requirements with the aspirational design.
Understanding the key purpose of the outdoor space will completely shape the design. It also affects the types of materials and finishes that will be required. Whether it’s for recreation, co-working or hospitality, the Kinley Raaft system enables a wide range of different materials to be incorporated.
Considerations for the design will include the typical age range of people using it and whether the space will need disabled access, or indeed will be used by children. Work space, for example, will have a completely different set of criteria to a recreational or private area. Disabled access will need more thought around navigating the site, access points and ramps, as well as having wider footpaths. School play areas will require different finishes and additional safety features.
Knowing the design requirements from the start will make specifying easier, as well as arranging delivery of products for when you need them.
A key challenge that we face on the roof terrace environment is having sufficient build up depth from the waterproofing to the finished floor level to allow for the construction sub-structure and pedestal system. Inverted roof systems (where the insulation is installed on top of the roofing membrane) can further limit the amount of available space so this is something that needs to be identified and established at an early stage. It is also important not to forget to take the door threshold levels into consideration.
If space is limited, then using 20mm porcelain tiles from Kinley’s Atria collection is a great option, as these can be set on the Raaft pedestal system with a total construction depth of as little as 32mm. This means that you can still create something amazing in a very challenging environment.
Conversely, podium courtyards can have an extensive amount of space available and it may be necessary to include some kind of void filler to reduce the construction depth. However, these zones can also provide valuable opportunity for water attenuation zones to assist with balancing drainage flow from the buildings and contribute to overalls Sustainable Urban Drainage (SUDs) requirements.
Taking into account the drainage provision of the roof terrace is also key. We’ve found in the past that drainage outlets can often clash with the positioning of pedestal supports or where foundations for planters are required. Identifying these early in the design process can save complications and frustration at construction stage.
It is also important to think about any special requirements for the terrace – for example, what plants might be needed, or the different surfaces that will be incorporated into the design. These can also affect the water drainage system required.
> For more, read our article: ‘Technical spotlight: Overcoming the challenges in designing and constructing terraces.’
When designing a roof terrace, there is the added complication of what is underneath. If the roof itself has not been designed to take sufficient load bearing capacity, it will need reinforcing. This is normally the key responsibility of the architect or structural engineer for the project. It is particularly important on refurbishments and when retro fitting roof terraces to existing buildings. Remember that soil is heavy, especially when wet, so be sure to do the calculations to ensure the roof structure can support your design!
Consider the logistics. It sounds simple enough, but it is easy to forget something that could ultimately hold up the construction, or stop it altogether.
One key consideration is to ensure that you can get what you are designing into the space, bearing in mind that a lot of construction for the building will have already taken place. It is quite likely that the roof terrace will be installed at the end of the project. For example, we have seen projects where contractors reach the 9th floor but have no crane on site, making it very challenging (and costly!) to get supplies to the roof space. Keeping this question in mind through the design and construction scheduling phases of the project can save a lot of time, cost and stress later on.
If you are designing or constructing a roof terrace, speak to one of our technical specialists who can help you making sure you have taken all logistics into consideration, and help you choose the right products to create the desired finish.