Chase cover replacement by local pros in McDonald

Checking the chase for square

Few chases stay perfectly square after years in the weather. Measuring both diagonals shows whether the top has racked into a slight parallelogram. A cover built as a true rectangle for an out-of-square chase gaps at two corners and binds at the other two. When the diagonals differ, the new top is laid out to the measured shape. We record all four sides and both diagonals so the fabricated cover matches the chase you actually have. A cover that fits the true shape also keeps an even skirt gap on every side, which looks neater from the yard.

Checking the termination height after roof work

Manufacturer instructions set how far the termination must extend above the roof. The rule in one manual we use calls for three feet above the roof penetration and two feet above any roof surface within ten feet. A thicker new roof or an added layer can change those measurements. We note the height as we work on your McDonald chase. If the chimney looks short for its surroundings, that becomes a separate conversation and a separate item on the estimate.

Comparing two chase cover quotes

Two quotes can both say chase cover replacement and describe very different jobs. Our estimate lists each of these items in plain language so a side-by-side comparison is easy. A lower price that leaves out the storm collar or uses a thinner sheet is a different job, even if both say chase cover.

• The metal and its grade, and the sheet thickness
• How the top is shaped to drain, and the collar height
• Skirt depth, drip edge and fasteners
• Whether the storm collar and cap are included
• How hidden damage under the old cover will be handled

Sealing washers and exposed fasteners

Where a manual allows fasteners exposed to the weather, each one needs a sealing washer that compresses under the head and closes the hole around the shank. Washers of the wrong material crack in the sun, and overtightened ones split. We set exposed fasteners with washers suited to the metal and check each one before leaving, because a single weeping screw can stain the siding below it. Where the manual calls for fasteners only through the skirt, none go through the top at all.