Hi. Just had our roof refelted, baton and new tiles fitted on our house about 2-3 weeks ago. We have had heavy rain and wind today and I went to put something in loft and just as I exited I notice the beam was wet. The membrane had a little wet patch by it where the baton gets nailed. I noticed this in a few places where the baton meets the beam so must be seeping in by the nail. Is this normal to happen with heavy wind and rain?