How to install fixed height pedestal paving

The use of fixed height pedestals makes it easy to install concrete paving slabs in applications such as balconies, roof gardens and built-to-fall roof terraces. Here are some key steps and installation tips for pedestal paving. 

How to use fixed height roof pedestals 

A fixed height roof pedestal is manufactured in four quadrants. These are joined together with a small link which can easily be snapped apart to produce segments of a half or a quarter. All the edges of the slabs can then be completely supported. This allows the concrete paving slabs to be installed around corners, edges and at the end of runs, minimising waste. 

Fixed height roof pedestals act as a guide when installing paving slabs and can help save time on site. The use of roof pedestals ensures there is very little wastage and gives a neat finish where the paving is installed flush against walls and parapets. 

Ensure the first row of slabs is correctly aligned in pedestal paving 

Using fixed height roof pedestals makes it easy to install the concrete slabs. It is important that the first row of paving slabs is installed to the correct line as this will then act as a guide to the remaining rows. Each paving slab should be lowered onto the support and then adjusted to ensure that straight lines are achieved. 

Roof pedestals are stackable to increase height 

A maximum of two pedestal units can be stacked on top of each other to increase the height. 

Installing stretcher bond and staggered joints in pedestal paving 

For stretcher bond and staggered joints on pedestal paving,  one of the joint lugs of the pedestal can be removed as shown in the image below, so that the slab will sit on half of the pedestal, providing proper support.

Inboard cutting with pedestal supported paving 

Cut slabs should not be less than half of the original size. To achieve this, inboard cutting must be used to avoid smaller pieces at the edges of paved areas. Careful attention to setting out can ensure that full units are installed in the more heavily trafficked areas, such as at doorways. 

What types of pedestals are available when installing pedestal paving? 

There is a vast range of pedestals available to suit all types of application, including roof decks, terraces and balconies. There is a pedestal to solve almost all problems that may be encountered on a project. These include: 

• Low height 

• Fixed height 

• Fixed height adjustable 

• Self-levelling adjustable 

• Slope correcting 

• Non-combustible 

Where would non-combustible pedestals be required? 

Non-combustible Euroclass A1 fire rated pedestals are available for projects using pedestal paving where combustible materials are banned.  

Balconies are now considered as part of the external wall and classified as a “specified attachment”, and the following applies. 

Where the construction is of either: 

New buildings, which are 

• over 18m, and
• in which people sleep

or for the refurbishment of existing buildings where: 

• changing the cladding would result in lower safety (i.e. recladding over concrete), or
• the building is changing in use 

Then the new legislation specifies that all components of the wall must be individually tested as non-combustible (European Classification A2-s1, d0 (limited combustibility material) or A1). 

What are the advantages of pedestal paving for roof terraces? 

In addition to simplifying the installation of the concrete paving slabs, there are several advantages when using pedestal paving for roof terraces. 

Pedestal paving eliminates the need for additional roofing materials 

A key advantage of using pedestals on balconies and terraces is that it eliminates the requirement for bedding sand or mortar. This reduces the mess and the hassle of importing such materials onto the roof of a building. The overall weight on the roof is also reduced, decreasing the structural load on the building’s foundations. 

Pedestal paving provides roof drainage that can be utilised as part of a SuDS scheme 

The pedestals used to support the concrete paving slabs create open joints between the slabs. This allows water to drain through the joints into the void below and be directed towards roof outlets. It avoids ponding on the roof surface and, when integrated into a wider SuDS (Sustainable Drainage Systems) scheme, it can provide effective first-stage water management.  

Rainfall captured at roof level can be: 

• Stored in blue roof attenuation layers to slow discharge rates into the network. 

• Directed into rainwater harvesting systems for reuse. 

• Linked with ground-level SuDS features such as permeable paving plazas or swales 

In this way, open-jointed paving on pedestals contributes to a multi-layered SuDS approach, helping reduce flood risk, manage peak rainfall, and support compliance with planning requirements. 

Pedestal paving reduces maintenance and improves roof access 

Pedestal paving requires very little maintenance. Routine sweeping is advised to prevent debris from accumulating, and washing can be carried out when necessary. Always consult the system manufacturer for specific maintenance guidance. If a concrete slab becomes damaged, it can be removed and replaced. This removable design also provides convenient access to any services running beneath the permeable paving, as well as to the roof’s waterproofing layer when needed. 

Where can I get advice on the installation and specification of fixed height pedestal paving? 

Tobermore has an extensive concrete paving range for use in fixed height pedestal paving applications. With a wealth of both technical and installation advice, we help to ensure customers can specify and install the pedestal paving that is best suited to their projects.  

Sam McBride, Tobermore’s Technical Manager, explains that Tobermore can assist customers: “We offer a wide selection of paving products suitable for roof terraces, roof gardens, balconies, and podium decks. When paired with fixed height pedestals supplied by various specialist manufacturers, these products create an excellent solution for any rooftop setting. Our roof-terrace support service helps customers assess product suitability, strength and loading requirements, compatible pedestal options, and installation best practices.” 

​​​If you have a project and are considering using a pedestal paving solution, we have a Roof Terrace Support service. Contact our technical team, who will be happy to support you with considerations including product suitability, strength and loading tolerances, pedestal compatibility and placement, along with installation advice.