This is a very fine example of a set of 60 balconies in mixed wood and steel frames on a timber-framed building.

This project, located on rue des Lyanes in the 20e The Metadeck project in the Paris arrondissement is particularly interesting because all the difficulties and single points that can be encountered in the manufacture of balconies with a Metadeck waterproofing system are present and have been resolved.

This is a timber-concrete frame building, built in a cul-de-sac that is very difficult to access. The architect's main requirement was to build balconies with wooden decking, with an integrated load-bearing waterproofing system, while respecting the constraints of finesse and an aesthetic appearance on the underside.

1- In this photo, taken axonometrically, we can see the structure of the balconies, with the steel perimeter structure, the railings and, in the central section, steel joists and timber-framed struts in Douglas fir.

2- This view from below shows the structure of the balconies, with the timber framework to which the Metadeck profiles will be fixed.

3- This is a group of several buildings, all built identically using the same watertight balcony system. MetaDeck profiles were used for all the balconies.

4- The sections have been delivered to the courtyard, cut to final size as they go along and then assembled on the upper floors.

Fitting and fixing the profiles

This short video shows the assembly and fixing of Metadeck profiles.
The profiles are pre-cut to size. Installation is very simple: simply clip the Metadeck profile onto the previous profile, insert two screws through the Metadeck onto the timber frame and move on to the next profile.
Once the pace is set, the installation of profiles moves ahead very quickly.

6- The first series of balconies has already been fitted with Metadeck profiles. The profiles are slightly recessed on the railing side so that water can drain into a gutter.

7- Metadeck profiles require very simple tools for installation: a radial saw to cut the profiles, a drill, a screwdriver and, in our case, putty to seal the façade.

8- We take a closer look at how Metadeck profiles are used.
On the right, the profiles are interrupted in front of the French window. There is a grating between the profile and the French window.
will be installed, as is often the case. There is also the Metadeck
which protrudes slightly towards the inside of the castle on the left.

9- At the French window, the Metadeck profiles were carefully masked with polyurethane sealant, particularly the triangular section, to prevent water from seeping into the non-watertight part of the profiles.

10- Once sealed, Metadeck profiles are 100 % watertight for life.

11- This photo shows the detailed installation and sealing of the Metadeck profiles in relation to the frame. On the left, we can also see the fire-resistant sheet steel angle on which Metadeck comes into contact.

12- The same view shows the French window frame and a good view of the area where the grating will be inserted between Metadeck and the French window.

13- Balconies form a continuous unit with external or internal corners. Metadeck profiles must therefore be able to follow the string of balconies, since Metadeck serves as a support for the decking.

14- Here's a detailed view of the fire-resistant sheeting, laid along the façade, and the wood-and-steel structure of the balconies. The balconies are quite narrow (80 cm), and the structure takes up a lot of space.

15- In this photo, we have a very good view of all the details of the balcony's construction system. On the left is the gutter (in blue), specially folded to meet the needs of this site. On the right, we see the fire-resistant steel sheet again, and just above it, a new angle iron, the drip edge, to ensure that the façade is watertight.

16- This is a detail view of the gutter with the Metadeck profile protruding inwards between the Metadeck profile and the gutter. There is an EPDM seal to prevent water dripping back inwards.

17- The whole design is quite "workmanlike", but the result is as good as it gets, with a completely invisible rainwater collection system, no gutters on the façade, attractive wooden decking and a perfectly aesthetic balcony underside.

18- View from above. We can see the Metadeck profiles draining into the gutter with the opening for the drip tray.

19- On this first section of balcony, the decking is complete. All that's missing are the gratings, which will be installed at a later date. The decking is easily fixed to the Metadeck. For this project, we chose to install treated pine decking, which is quite economical. It is of course possible to install any type of decking in exotic wood, composite, bamboo, etc.

20- The previous photos show the installation of the Metadeck profiles on the inset corner. Now we see the installation of the deck boards with the 45° cuts, which are quite successful.

21- A lovely view, in bright sunshine, from our watertight balcony, with Metadeck profiles

22- Here's a nice photo of the balcony soffit. From the left, you can see the fire-stop sheet, the Metadeck profile and the board supporting the gutter. As the balcony is quite narrow, the Metadeck is obviously not very visible because of all these constructional constraints.

23- However, Metadeck provides outstanding waterproofing and support for deck boards, enabling the project to be implemented quickly and reliably.

24- This is the overall view of the main building. All the balconies have been finished with Metadeck waterproof profiles and wooden decking. Together with the wood cladding on the facade, the result is a highly successful ensemble.

25- The view from the underside of the balcony also shows a very fine finish, made possible by the use of Metadeck watertight profiles.