ᐅ Which conduit pipes are typically used for garage connections?

Hello forum,

Construction of my double garage has already started. It was agreed with the construction company that the plumbing work would be done. The strip footings (about 1 meter deep and 60 cm wide (40 inches deep and 24 inches wide)) have already been created with reinforcement cages. The slab (about 15 cm (6 inches) thick) is still pending.

Unfortunately, I noticed that the contractor has not yet planned the conduit for the electrical installation. It was also my oversight not to possibly include a conduit for a water pipe in the garage. However, due to the strip footings and frost depth, this will likely no longer be possible.

The electrical installation, on the other hand, should not be a problem as the slab has not yet been poured. The strip footing itself will also be extended upwards by about 20-30 cm (8-12 inches). So there is some flexibility there as well.

My question: What kind of conduits are generally used for electrical installations outdoors? The double garage is approximately 15 meters (50 feet) from the house. Would you use 100 mm (4 inch) rigid pipes, or flexible cable protection conduits / corrugated conduit / installation pipes? How deep is it recommended to bury such an underground cable in the garden?

100mm (4 inches) PVC pipe is always a safe choice... I would go at least 60cm (24 inches) deep. If it's shallower, you need to remember exactly where it is to avoid damaging it when digging...

110mm (4.3 inches) is not bad. Although 75mm (3 inches) would probably also work.

For the length, I would definitely install two cleaning pipes (the ones with rectangular covers) to be on the safe side and make sure to mark the spots well so you can find them again.

For bends, don’t use 90-degree sections; it’s better to use ones with 15-degree angles.

Definitely avoid corrugated pipes. You will catch on every small irregularity (and there are plenty over 15 meters (50 feet)) when pulling through.

Is water involved as well? Then the depth must be frost-free at least 80cm (31.5 inches), depending on the region.
Your shell builder will know this, though.

Thank you. I have now used a 110mm (4-inch) PVC pipe. It goes about 80cm (31 inches) deep until the foundation. Then I chiseled the foundation slightly with the Hilti and built it up with 2-3 corners of 30cm (12 inches) each. I am only about 30cm (12 inches) deep in the foundation. That means the pipe extends about 30cm (12 inches) up from the ground into the foundation and is only 30cm (12 inches) deeper in the concrete where the soil ends. So, not ideal, but at least it’s something.