Is it possible to use underlagpapp instead of syllpapp? I am going to extend the boiler room and the sill will be located about 60-70 above ground. I think it is YAM 2000 on the underlagpapp.
You probably can, even though it's completely the wrong place to save on. There's no easy way to fix it afterwards. Maybe not the answer you wanted, but better safe than sorry.
