Drainage pipe at thatched roof house

We are remodeling our thatched roof house, or rather it is getting an extension and thus a roof extension. The original part of the house has the yellow drainage pipe all around, but somehow I don't really trust it. I always wonder how much it has to rain for water to be visibly splashing out of the end piece... So my question is, does anyone know a better solution? Or do I not have to worry and can continue the yellow pipe?

Hello floor display case

The HT pipes are only intended for indoor use. Not suitable for outdoor use. You should reconsider the connections to the HT pipe. In my opinion, it’s a botch.
And the (yellow) HT pipes are not drainage pipes but wastewater pipes.

Steven

The yellow pipes are typical drainage pipes, right? And why don't you trust that? It is a proven system, but it requires maintenance...

Could it be that the HT pipes are normally located inside there and that the extension will be added there?

yes, first of all, thank you... I also think that the yellow pipes are DrainageRohr, as they have small holes everywhere... the reason I don't really trust that is because I have specifically checked during and after rain over the past year to see if water ever comes out at the end piece, but it doesn't.... and furthermore, yes, where the other pipes run, the extension abuts.... when it's finally finished sometime, the drainage definitely needs to be run around once.....

Hello display case

then you have suspenders with a belt. The drainage is obviously not needed, but it never hurts. Even if it only represents the very last reserve.

Steven

I don’t understand that. ... the thatched roof is extended on the annex. Then drainage is also necessary there on the sides of the house. ...