Exposed concrete and recessed spotlights

Exposed concrete installation is considered the gold standard of installation options and should be carried out professionally and to a high standard. Most proprietary solutions are relatively expensive, but when used correctly, they avoid common problems such as cracks, crooked cones or installation boxes, or almost impossible cabling.

Precise planning of exposed concrete spotlights

The precise, sensible placement of the light fixtures is essential in exposed concrete, as no changes can be made afterwards – not even by force. The reason for this is the "regular irregularity" of exposed concrete. Although there are special restorers, even they cannot rectify planning errors, but can only conceal imperfections.

Therefore, before placement, it should be determined exactly which product with which characteristics will be selected. Will spotlights with wide or narrow angles, recessed or even swivelling, be chosen? Once this has been decided, the placement should be carefully considered. Effective lighting of walls, functional lighting of furniture or work surfaces is not a major challenge for experienced lighting designers – distances and angles of incidence should be clear. Even greater care than usual should be taken to ensure that the plans are up to date and accurate.

Choosing the right product

Choosing the right product is crucial. When it comes to exposed concrete recessed spotlights, there are two types of products: those with frames (which are relatively unproblematic) and those without frames.

• Exposed recessed spotlights with frames can be installed in a standard box (e.g. Kaiser's standard box). The cut-out should be precisely defined, as should the size of the frame that overlaps the box. If this is relatively wide or generous, there is no need to install special solutions such as exposed concrete sleeves, as any imperfections will be covered by the spotlights. If the frames are rather narrow (e.g. with a 2.5 mm overlap), exposed concrete sleeves should definitely be used.
• Exposed concrete recessed spotlights without frames are installed using specially designed boxes. These boxes either sit flush with the exposed concrete or form a special shape (cone or curve) using special inserts. The latter option is particularly attractive and homogeneous, as the aim is to leave the exposed concrete ceiling as untouched as possible.
• A third option would be to create the holes in the exposed concrete using the concrete cones that are normally used for formwork. We have also successfully implemented this in one of our projects. This solution is cheaper, but much more adventurous than a specially prefabricated solution. Here, particular attention should be paid to ensuring a good connection between the cement cone and the cable conduit. Spotlights for this application must be custom-made and can therefore be expensive. Particular attention must be paid to adequate cooling, as there is little space for air in the normal supply pipes. The heat sinks must therefore be sufficiently large.

Here we see the nailed Georg Bechter exposed concrete capsules at one of our project buildings (client: A Leite GMBH, project: Urban Park).

The capsules were nailed shut with formwork panels, after which the pipes were inserted and the iron fixed in place.

The formwork panels are removed, leaving a uniform hole in the exposed concrete, which can be conical, rounded or flush, depending on the type of formwork plug selected. Here, we have chosen the rounded formwork plug.

The spotlight is seamlessly inserted into this "mould" in the exposed concrete using a bayonet suspension. There are no visible clamps or springs. The spotlight can thus blend homogeneously into the material.

Update to follow as construction progresses...

Standard recessed spotlights for exposed concrete

Integrating standard recessed spotlights into exposed concrete

There is also a much simpler way to integrate a standard recessed spotlight into exposed concrete surfaces. To do this, it is advisable to select the appropriate spotlight well in advance of casting the first ceiling and to study the technical data sheet. It is important to choose the mounting box so that the cut-out, overlap and installation depth are suitable for the selected product. Various manufacturers of exposed concrete recessed boxes offer ready-made solutions, such as Kaiser. Kaiser offers the standard box + exposed concrete sleeve for exposed concrete recessed spotlights. This sleeve prevents concrete from flowing in at the sides, thus keeping the edge of the spotlight clean. This means that spotlights with small overlaps (2.5 mm) can also be used without creating any imperfections. Minimal imperfections must also be taken into account with exposed concrete and can only (and even then not always) be avoided with special solutions (such as Georg Bechter boxes).

Here we see a bicycle garage with an exposed concrete ceiling and exposed concrete recessed spotlights. These were made in a custom colour that matches the concrete. This has resulted in a relatively inexpensive solution that, at first glance, resembles a cast concrete solution.

Integrating recessed rails into exposed concrete

It is also possible to integrate LED recessed tracks into exposed concrete. For more information, please refer to the article LED recessed tracks, in which we discuss this in more detail. However, consultation is always necessary for the exact procedure. The integration of LED recessed tracks into exposed concrete poses various challenges that can be even more delicate than the integration of recessed spotlights.