In the 1970s it was the dream house of a young family, but decades later it is a renovation project with old materials, outdated construction and processing techniques and “building sins”. Therefore – and also for taste reasons – the new owner wanted to bring the bungalow in Darmstadt in the south of Hesse up to date.

The 80 square meter terrace was also a constituent of the forthcoming renovation. The client's request: to have a visually seamless transition from the inside to the outside area with large-format tiles laid in a bond. However, the problem was that this is not possible with normal bond laying. Because movement joints at regular intervals would then have been essential – and the joint patterns in the interior and exterior areas would have been different. Therefore, the client decided to get comprehensive advice from a Gutjahr professional partner as the installer.

Combination of fixed and loose laying

Tile specialist Langkammer GmbH & Co. KG from Otzberg recommended that the client use 70 x 40 cm tiles as 2 cm ceramic elements, and have them laid using the TerraMaxx PF method. This is a combination of fixed and loose installation. Powerful surface drainage ensures that surface water is quickly drained away. It also prevents the fixing points with which the ceramic elements are glued to the drainage from standing in the water. In the long term, this prevents efflorescence and damage to the covering. It was also an important argument for the client because he is one of the “best agers” and would like to enjoy the finished terrace for a lifetime.

It was a wise decision to involve the Gutjahr professionals in the renovation. This became evident no later than when the old terrace covering was torn down. Because it turned the project into an extremely tricky business.

Major challenges

Originally, the terrace consisted of exposed aggregate concrete slabs laid on a concrete slab in the mortar. Once the old covering had been chiselled off, it was evident that “the underneath” was anything but optimal. For example, the concrete slab did not have a fall, which had to be created later. As a result, only 3 – 4 cm of construction height remained after the required fall formation.

Other challenges: The terrace has a partial cellar, but there was no waterproofing. Nor were sufficient flange widths available for allowing fixtures such as the light shaft cover and connections to the patio doors to be connected with a mineral sealing slurry.

Reliable solution – for the long term

For the installer, this meant that additional work was required that had not been planned beforehand after the old pavement was torn down – with a tremendous amount of lost time.

The first step in the new construction was the introduction of a sloping screed which sloped towards the garden. In order to make up the lost time, the tradespeople decided against using a liquid film as the waterproofing and use the Gutjahr DiProtec SDB quick sealing membrane, which could be laid the day after the screed had been put in place.

This waterproofing system can be laid loosely on the substrate without preparation or waiting time. Then it is also immediately rainproof. In contrast to mineral sealing slurries or liquid waterproofing, no priming work is required. Because of the defined layer thickness and the self-adhesive system sealing tapes, installation is also easy and safe.

Particularly important for the construction site in Darmstadt: Because of the vapour pressure equalizing fleece on the underside, the Gutjahr quick sealing membrane can also be used on damp substrates, i.e. also on the screed that was applied the day before. The very tricky connections at the patio doors and the light shaft cover were reliably sealed in the system with DiProtec FLK.

Low construction height

The problem of the low construction height - as well the laying in a bond - could be solved using TerraMaxx PF. To do this, the tradespeople rolled out the AquaDrain T + surface drainage on the waterproofing. This was followed by a special fixing compound with which the coverings were glued at certain points. This fixation makes the covering look like a solid laid surface. The joints were also sealed with MorTec SOFT special joint filler. This also provides a high-quality look and the surfaces are easier to keep clean. Special expansion joints were not required, because each joint has a “crumple zone” which can absorb tension. After the completion of the work, the construction height was around 4 cm including the drainage mat and the covering – a real precision landing

Harmony between inside and outside

The client had chosen ceramic elements with a concrete look as the covering. In the living room, tiles from the same range were laid with a joint pattern that was identical on the outside. The outdoor covering harmonizes perfectly with the floor covering in the living room. Together they form a visually uniform, spacious area. The floor drain in front of a viewing basin and the ventilation of the glass-covered light shaft were implemented with drain grates with the shadowline design.

Spacious overall impression

After receiving expert advice from the Gutjahr professional partner, the client decided on the proposed solution. The work was carried out accurately and neatly within 3 weeks. The client and his family were therefore able to enjoy the summer on the newly designed terrace – which is now an extended living room in the truest sense of the word

Information about the TerraMaxx PF method

The TerraMaxx PF installation procedure combines fixed and loose installation, making it ideal for large-format slabs. The carrier is the AquaDrain T + surface drainage mat, which is laid loosely. The coverings are then fixed at certain points with a special adhesive so they can neither migrate nor wobble. But the installation is faster and easier than classic fixed installation. Another advantage: The joints can be closed with MorTec SOFT special joint filler without causing any tension problems, creating a uniform and permanently damage-free area.

Products used

Similar project reports