Water on flat garage roof problematic/dangerous?

so we also had a similar situation. There was a procedure, but water still accumulated at various spots from time to time. The developer said it evaporates or it is within the norm.

He then, at his own expense, had all the roofs, including those of the neighbors, planted.

No, we want to use the roof as a terrace...

The drain is located on the left side of the photo, roughly in the middle.

I think I need to take care of a new drain.

Since my architect says this is normal, I probably need an expert opinion to demand the defects to be fixed from him.

Or what do you think?

Hello Maronisch

the drainage is at the highest point. No slope towards it. That is stupid.
Are you still building up the terrace? Then it could be compensated again. But as it is now, it is wrong. The drainage should always be at the lowest point, otherwise it makes no sense. For you, it is an overflow.

Steven

Only a specialist lawyer for construction law can reasonably advise you on this! It first depends on what was agreed upon with whom. Afterwards, it is questionable whether having the right also means getting the right. In the case of a garage, I would advise against a lawsuit. Since you are planning a terrace, I see it somewhat more nuanced.

Are you still adding a terrace structure? Then that could be compensated again.

The waterproofing layer will certainly not be changed by a terrace structure. It will rather get worse, the water stands under the terrace. As I said, with a garage: it doesn’t matter, the roof is tight, the water evaporates. But if a terrace is put on top, the water stands under the terrace construction on the roof. One should choose a construction that is as open as possible.

I would try again to calmly clarify the whole thing with the architect (assuming he is responsible). Dismantling and rebuilding does not have to be the only solution. It should be discussed with an open mind how a technically clean condition can be achieved even with a terrace; without standing water.

So a defect. From the shell builder or from the architect?

From the architect - unless the shell builder did not work according to plan.

What are the consequences?

Standing moisture.

Nevertheless, they do what they are supposed to do: they are watertight.

Even the tightest pond is a pond and not a roof. A drain should be designed so that no evaporation needs to assist it.

No, we want to use the roof as a terrace...

Then it is often planned without a slope to avoid complicating the substructure of the covering. I fear there is a good chance that the expert will then find it completely acceptable.

Super thanks for your feedback.

The architect sticks to his opinion that everything is okay. The shell builder says he had tended to build the process differently.

What would you recommend for a structure that can later be used as a terrace?