It’s impossible to properly set up new flashing and underlayment should you don’t tear off the old roof beforehand. When tearing off the prevailing shingles, remember to take away all the old nails or pound them flat. Protruding nails will tear holes in your new shingles. If you’ve movable objects close to your home and also you’re nervous they could get broken, relocate them.
It additionally seals around nails, which retains water from leaking via nail holes. If you want more ventilation, cut extra vent holes in the decking with a circular noticed and set up vent flashing. Installing shingles round attic vents, plumbing vent stacks and furnace stacks is basically the identical process.
When putting in the felt paper over a stack, it is OK to make an oversize gap. But before you roll out the row of paper above the stack, reduce a 2- or three-ft. section of self-stick underlayment, reduce a hole in it slightly smaller than the diameter of the stack, and slide it over the stack. Make sure the piece is massive sufficient in order that the next row of felt paper overlaps the top a minimum of a few inches .
Windblown heavy rain and/or snow can pressure water up and beneath even correctly put in shingles. Buy it at roofing provide companies or house facilities. In severe climate regions, most constructing codes require applying it 3 to 6 ft. up from the eave (minimum of 2 ft. past the exterior wall).
Call your constructing inspector for local details. Position them so the adhesive strip is towards the bottom and dealing with up. Water can get in the seams between any two shingles, but that is OK as a result of shingles overlap and the seams are staggered. But if you don’t use starter shingles, water will run in between the seams on the primary row and proper onto the underlayment, growing the chances of a leak. The starter row shingles are only half as extensive as a full shingle. If they have been full measurement, the top half of the first row would have three layers of shingles as an alternative of the 2 the remainder of the roof has, inflicting a visual hump.
Install the second course similar to the first, utilizing the guidelines on the underlayment to get the correct overlap. When an ice dam varieties on a roof (normally brought on by poor attic insulation/ air flow), ice and water can work their way up beneath the shingles and leak again into the house. Also, strong winds can blow rainwater underneath shingles. Self-stick roofing underlayment (often called “ice-and- water” underlayment) can forestall this as a result of it sticks to the roof decking to seal out water.