I'm currently installing my first metal roof over shingles. I started putting down underlayment today and was putting buttoncaps at every marked spot on UDl 25 . then went to every other one. Is it really necessary to use so many caps? It was really time consuming and seemed overkill but I wasn't sure.
Guest User
2017-04-09 01:11:59.000000
The risk with synthetics underlayments is that, when the installed underlayment is walked on, it will pull against the fasteners and tear the underlayment. The use of a fasteners approximately every square foot is to prevent enough movement of the product that it tears against the fasteners. I know it's a lot of fasteners but my recommendation is to fasten the product where it is marked.