Plan/internal/roof drainage behind surrounding parapet

Our current plan includes an internal roof drainage system. The drainage is located behind a continuous parapet, see photo.

Our future roofer strictly advises against this, as in the event of damage to the gutter, moisture would enter the house.

What is your opinion?

Then the roofer should do the roof drainage properly, man ;-)

In principle he is of course right, but it is also his job to do it correctly. And this is not the first time it is being built ...

That is probably true. He can also execute it according to the standard, but he warns that gutters naturally eventually suffer defects and then you have a problem. Therefore the question whether anyone has had negative experience regarding this!? How can it be prevented? How does it behave in winter when ice forms?

Nothing more needs to be added. There are certainly standards, technical guidelines, or at least technical data sheets for such internal roof drainage systems and the building materials to be used. Possibly even complete system solutions. Your roofer should know and also follow all of these. Such a statement would make me suspicious and prompt me to closely inspect the work.

Moin Moin

I understand this to mean that the DD points out the risk of significant damage in the event of a defect. Even with proper processing, damage caused by aging and weather influences as well as roof tiles that have slipped down during a storm cannot be avoided.

Olli

Hello,

Our current plan includes an internal roof drainage system. The drainage is located behind a continuous parapet. Our future roofer strictly advises against this, as in the event of damage to the gutter, moisture would enter the house.

This is a nice roof shape, which allows for architecturally good accents.

The roofer is obligated – if he does his job correctly – to point out any potential risks of damage to you. On the other hand, damage can occur wherever water is involved. If the location of the gutter is sealed in accordance with regulations, no problems should be expected here. You even have less trouble with leaves and thus cleaning the gutter.

However, if the roofer has made you "furrowed" and your courage to implement your planner’s idea decreases, it can also be done as in the attached picture. The fire wall is still extended upwards, but the gutter is conventionally attached anyway ;)

Rhenish greetings