End of August, the metalwork on the spiral staircase platform was finally complete, and access was therefore ready to start with some challenging activities…

This meant that work could begin on constructing the foundation for the steel column.These works began with cutting into my flat roof – something you only do when you have thought it through very carefully… This step marks a decisive moment, because once the roof is opened, there is no turning back…

The reason for cutting into the roof was simple but crucial: the telescope pier needed a solid foundation that connects directly to the reinforced concrete slab of the house. Only in this way could I make sure that vibrations – whether from someone walking inside the observatory or from the wind shaking the dome – would not travel up into the mount and finally in the optics.

The connection to the concrete slab of the house was realized with a 300 kg reinforced concrete foundation (60 x 60 x 45 cm) …and yes, I did it again by myself supported by my lovely wife Natascha and my great son Lukas (…thanks again to both ❤️) – carrying up every kg 3 floors to reach the final place on the roof …)

To protect the construction site on the flat roof, I set up a weather shelter – essentially a tent that kept the work area mostly dry shielded from wind and rain. This made it possible to carry out the concrete and installation work without being at the mercy of the weather.

The actual base for the steel pier was then realized with a 70-kilogram (1.5cm thick) steel plate, anchored by four M20 threaded rods embedded deep in the 300kg foundation using grouting mortar.

In the next photos you can see the heart of the pier foundation coming together. On top of the foundation block I installed four M20 threaded rods that were cast into the concrete. They carry the base plate for the pier, which is double-coated for corrosion protection and sits on nuts and washers, which let me fine-tune both height and tilt. This adjustable interface is critical: I can level the pier perfectly now and still re-adjust it later if needed (maybe for other telescope rigs …). The elongated service slots in the plate provide clearance for alignment and future attachments.

The first image shows the trial fit and alignment process: tools at hand, nuts backed off, and the plate being positioned and checked. Once the final alignment is locked, the steel pier bolts to this plate, forming a mechanically decoupled system from the observatory floor. The result is hopefully a rock-solid, vibration-isolated base so that the mount and optics remain perfectly steady during long exposures.

The observatory floor is built as a decoupled structure. A grid of aluminum joists sits on height-adjustable pedestal feet, which distribute the load across the roof without penetrating the waterproofing. The joists carry the finished deck, while a protection layer separates the substructure from the roof surface. The telescope pier remains completely isolated: its concrete block is wrapped and sealed (the only work done by a professional …), and the deck frame stops short of it so no footsteps or vibrations can travel into the mount. This way, the room can be walked on freely while the pier stays rock-solid for imaging.

The finished deck is made from 27 mm film-faced plywood (“Siebdruckplatten”). These panels have a phenolic resin surface that is hard-wearing, moisture-resistant and slip-reduced—ideal for an exposed rooftop environment. The sheets are laid on the aluminum joist grid with staggered joints and a small expansion gap, then fixed with stainless, countersunk screws. All cut edges are sealed to keep moisture out. Around the pier, the panels stop short to maintain vibration isolation and to form a neat, removable service opening.

„First Light“ of the brand new Skywatcher EQ8-R Mount

Kind of a „First-light“ moment for the new Sky-Watcher EQ8-R on the steel pier: I simply had to test-fit it before the rest of the project continues. The impression is immediate—this is a genuinely massive, observatory-grade mount, exactly what I wanted for a future dual-telescope setup. With 50 kg payload, the EQ8-R gives me the headroom to run maybe also two instruments on one mount without pushing the limits.