Ice and Water Shield: What it is and how properly install it.
Ice and water shield is a rubbery substance that comes in a roll just like felt paper or tar paper. It is very sticky on the bottom side and gets installed right to the wood deck at the bottom of the roof line and down the center of any vally. It is very sticky on the bottom side and once it is installed, it adheres right to the wood and is hard to get up once it is installed.
Ice and water shield is an ice and water protect-ant that helps a leak from coming through your roof and into your attic. The most common place to get snow and ice build up is along the bottom of your roof and in valleys. If this ice and water was to get under your shingles the ice and water will help prevent it from getting through and causing a leak. It is a code requirement in Michigan and in other parts of the country due to the extreme weather conditions in these areas.
There are many different manufactures that make ice and water. Some of these brands in my opinion are better than others. I break it down to good, better, best. I would never put a low grade ice and water shield on any roof. Most roofs are fine with a mid grade and only in certain roof designs and slopes do I feel a high grade is needed.
When installing the ice and water shield to the bottom of your roof line there are two ways to install it. First you put your drip edge on at the bottom and then your ice and water shield over the top of it. Next you install the ice and water shield on, fold it over the edge, and then put the drip edge on. If you have a gutter the ice and water shield would go over the top of the inside of the gutter. In the valleys you want to start at the top of the valley and roll it down the center of the valley.
Make sure you follow the installation instructions when installing it. Also make sure you check with your town on their rules. Some towns want two rolls of ice and water along the bottom. Others want two rolls up of ice and water if you have an extended overhang.