Underlay adhesive loosened

Hello everyone, because the underlay membrane is sagging, I cannot properly glue it together from the inside. The manufacturer of the underlay membrane is unknown, there is no print visible anywhere. So with Siga Crall, can you safely glue directly onto an underlay membrane?

Siga Crall please inside. Yes, sticks like hell on something like that. There is also a green one from Siga, I forgot the name, it is even stickier.

of course from the inside :P how do you want to get to it from the outside with a reasonable exterior wall ^^

You are right, nevertheless I would use an adhesive that is also suitable for outdoor use.

: we used LDS Solifit on the vapor barrier for bonding. According to the manufacturer, this is only suitable for indoor use. Why? Possibly long-term function, temperature, weather and aging resistance, no idea?

For the underlay membrane, the sealing agent recommended by the manufacturer suitable for Foxx Plus Delta was used. Now, how it looks if nothing more comes between the inside of the underlay membrane and the house, meaning the underside of the counter battens is the same as the inside of the house, I don’t know.

If I had to buy a tape or a sealing compound anyway, I would just play it safe and use the recommended product.

I’m not exactly a burned child, but a partially drowned child: our insulation between the rafters partially got soaked due to improper sealing of roof penetrations – maybe that’s why I’ve become overly cautious...