Diffusion foil on roof, adhesive spots are leaking!

Hi guys,

I built a little house in 1997. The company from which I bought the house back then consisted of 2 architects. The architects still exist, but the company does not anymore. The company that installed the diffusion foil probably still exists as well. Today I moved my satellite dish to make room for the photovoltaic system. In the process, I found that the diffusion foil is no longer sealed. Back then, they rolled 2m or 4m rolls over the roof and glued the seams together with a special tape. This tape is now completely dried out and no longer sticks. Now I practically have 3 slits in the foil on each side of the roof from the ridge to the gutter. What should I do, can I still claim this, is this a hidden defect?? Maybe someone had a similar case???

Regards, ariovist8

Hello ariovist8

What do you understand by diffusion foil? There is only one vapor barrier and that is on the inside of insulated pitched roofs (so that moisture from the house does not get into the insulation).

And there is a series of underlay membranes that are on the roof. However, they are laid horizontally towards the eaves (gutter) with an overlap of at least 10 cm; with flatter roofs, more overlap is used. Vertical installation of the foil is not correct. There are adhesive tapes but they do not stick forever either.
What kind of foil is it (PE or more like a kind of paper or fabric?)
Is your roof insulated?

Best regards, Sven

There is nothing left to complain about. The warranty period has long expired...

Hi!

Apparently an attic space not used as living space and therefore not heated. Still vapor barrier and insulation.

I think it's great that you never had problems with mold – and now with this "forced ventilation," it will probably stay that way.

But – where was the problem now?

Best regards,
Tomtom.

Yeah, where is actually the problem? As long as the insulation does not get wet, you have no problems.

Hello ariovist

I completed my training as a roofer in 1997, back then the membrane was always laid horizontally to the eaves, and that has not changed until today. So it is a defect, even if the architect claims that this is how it is done. Then it must be vapor permeable, the company Dörken has something like that in their range, and it is actually a so-called formwork membrane. The membranes are already stapled to the rafters, unless there is formwork on the rafters, then of course the underlay membrane is also placed on the formwork.

And @ Häuslebauer
As long as no tiles are broken and no water gets under the roof covering, he will have no problem. It is and remains a defect.

Best regards Sven