Roof terrace on torch-applied membrane

Torch-applied roofing membrane is one of the most commonly used waterproofing materials on roofs, balconies, and terraces. However, applying the waterproofing itself is only the first step. Equally important is the way the usable surface is finished.

Why do traditional terraces cause problems?

The biggest threat to a terrace is water. Even minor damage to the grout or the surface can cause moisture to gradually penetrate into the lower layers of the structure - the walls and the thermal insulation system. When pavers are bonded with adhesive (as in the case of a traditional terrace), any sudden temperature change, strong sunlight, or freezing water in the grout damages the protective layers, and over time, water seeps into the lower parts of the flooring.

Any damage to the insulation will require repair as soon as possible. At first glance, it may seem that all the grout joints on a bonded terrace are perfectly filled, but over the years, even with small gaps, water will begin to erode and expand, and what initially seemed like invisible defects will turn into serious problems.

That is why, over time, the following may appear:

  • cracked pavers,
  • crumbling grout,
  • delamination of the surface,
  • leaks to lower floors,
  • water stains, fungus, and mold.

In practice, this means that even a well-executed bonded terrace may require costly renovation after just a few years. Moreover, repairing individual damages often provides only a short-term effect.

Raised deck terrace on roofing membrane - how does it work?

A raised deck terrace is based on a system of adjustable or fixed pedestals that create a space between the waterproofing and the usable surface.

On the pedestals, you can lay both pavers (ceramic, concrete, stone) and joists (wooden, composite, aluminum) with decking boards.

The pedestals ensure that the terrace flooring is not permanently connected to the roofing membrane. This way, the surface material has the ability to move as a result of use and weather changes. Moisture does not accumulate in the insulation layer, nor is it exposed to damage. This is possible because we can create slopes on the substrate (standardly around 2%), which freely drain excess water from the surface.

Rainwater flows freely through the gaps between the pavers or boards and goes directly onto the waterproofing layer, from where it is drained to roof drains.

This solution eliminates the main cause of problems occurring on traditional terraces.

Old and worn-out terrace before renovation Wet wooden terrace with flower pots and a view of the garden Damaged terrace with ceramic tiles requiring renovation Detached and damaged terrace paver by the balcony door Damaged thresholds and cracked terrace pavers at the terrace door Large terrace with pavers and a linear drain on the roof of the building

Finishing the terrace surface on roofing felt

The surface of torch-applied roofing felt is problematic with traditional installation techniques — not only is it uneven, but it is also easily damaged.

In the raised deck terrace system, this problem disappears.

Terrace pedestals can be placed directly on the surface of the torch-applied roofing felt. The wide base of the pedestals will not damage the roofing felt, and their diameter will evenly distribute the live load.

However, on roofs and large usable terraces, it is recommended to use protective pads made of SBR rubber granules.

The pads:

  • protect the waterproofing from abrasion,
  • additionally dampen vibrations,
  • help distribute loads evenly.
Elevated terrace with ceramic pavers on adjustable pedestals

Example of a terrace design

One of our clients had a terrace of approximately 80 m² on the top floor of a residential building.

The terrace had all the typical problems:

  • cracking pavers,
  • falling out grout,
  • leaks,
  • moisture in the subfloor layers.

It was decided to completely remove the existing surface and the moistened subfloor layers. Then, a new waterproofing with torch-applied membrane was installed, and a raised deck terrace was mounted on adjustable pedestals.

The result was a completely sealed and easy-to-service surface.

Removing pavers on the roof

Long roof terrace with railing and tiles in a residential block Preparing the waterproofing and roof drain for terrace installation

Removal of old layers

Removal of old terrace pavers and preparation of the substrate with waterproofing

Exposed previous waterproofing

A roof terrace is particularly important in terms of waterproofing.

On top, torch-on membrane was laid with the appropriate overlap. The waterproofing issue is taken care of.

Renovation works on the roof terrace with visible waterproofing layer Leaking waterproofing and substrate preparation at the terrace door

Roof terrace - installation

Installation of ceramic pavers on adjustable pedestals on a rooftop terrace

Raised deck terrace system on roofing felt - a simple solution to a difficult problem

In the photos we see a finished paver surface - aesthetic and clean, and above all - durable.

Do you already know the raised deck flooring technology?

Adjustable pedestals are placed and pavers are laid on a raised deck terrace. Long raised deck terrace with grey ceramic pavers with railing

Roof terrace with WPC or HDPE composite decking

Terrace on torch-applied roofing membrane, exterior terrace with grey gres tiles next to a wooden door Construction for a raised deck terrace with pedestals and joists Modern WPC composite decking terrace at a garden house Elegant terrace with large-format gres tiles by the pool Installation of concrete pavers on adjustable pedestals on a raised deck terrace Installation of a raised deck terrace with gres tiles on adjustable pedestals Installation of a wooden raised deck terrace on pedestals and joists Modern rooftop viewing terrace with a grill zone and glass railings Long wooden terrace on a balcony with a glass balustrade Wooden terrace with a view of the river and historic architecture