When working on sealing in chimneys, it can be a tough job, especially when you are dealing with a notorious leak source, one that is around a chimney on a home. The roof protection decking can settle and move separately from chimneys, making it even more difficult. Install leak barriers to accommodate this movement. Install Shingle-Mate or Deck Armor roof underlayment flush to the leaking chimney wall; install a full 36″ of Weather Watch or Storm Guard leak barrier over the roof deck underlayment.
Run up the chimney sides 5″, the leak barrier should run up the chimney in question up the sides a minimum of 5″. Then, seal firmly into place by pressing the membrane, sealing in the chimney wall area, and seal to the Shingle-Mate or Deck Armor roof protection along the deck of the home. Completely cover crickets, the chimney crickets should also be completely covered with leak barriers as well. Install the shingles and the step-flashing over the leak barriers that were just installed on the roof.
To divert any leak water back out over the roof shingles at chimney front. Install Single-Mate or the Deck Armor roof decking underlayment, making sure it is flush to the chimney wall around the entire chimney. Then, install the shingles, making sure to trim them flush to the chimney front. Install the leak barrier of your choice 5″ minimum up to the chimney front; install this over the non-exposed area of the shingles at chimney front at a 5″ minimum.
Be certain to leave the shingle sealant exposed at this area under the chosen leak barrier protection that is being used on the area under also the roof deck protection above the chimney. Go up the chimney side’s 5″ minimum again and seal to all the areas by firmly pressing the membrane to the surface. This method will divert any water that enters past the flashing and shingles back out of the roof system itself over the shingles that are installed.
There are two instances where you would install either Weather Watch or Storm Guard leak barrier at the chimneys. Over the crickets of a home on the roof, making sure to abide by the chimney details that are set forth by code, and over the shingle method of sealing in a chimney. Making sure to go by these procedures will ensure your chimney on your home will be well protected against the weather elements.