Chimney animal removal and screened caps in Lake Magdalene

Timing chimney work around chimney swifts

According to the U.S. Fish and Wildlife Service, chimney swifts arrive in the country in March or April and leave in August or September. The agency suggests having the chimney cleaned between September or October and March or April, while the birds are away.

We plan cleaning and capping inside that window for chimneys with a swift history. Booking the work in fall or winter leaves time to finish before the birds return.

The same guidance suggests using a fireplace only during the part of the year when swifts are away. A fall inspection and sweep fits that timing and has the chimney ready before the cooler months.

What the code says about chimney cap screens

Florida's residential code sets rules for spark arrestor screens on masonry chimneys. The screen openings must not let through a sphere larger than half an inch or block one smaller than three-eighths of an inch, and the screen material has to hold up to heat and corrosion no worse than 19-gauge galvanized or 24-gauge stainless steel would.

That section also sets the arrestor's net free area at no less than four times the flue outlet's area. A properly sized screened cap meets those rules and keeps birds and squirrels out without choking the chimney's draft.

Choosing the right cap style for the chimney

Caps come in more than one form. A single-flue cap fits one flue and is fastened to it, while a larger cap can mount on the crown and cover several flues at once. The right style depends on how many flues the chimney has, how they sit on the crown and the condition of the crown itself.

Whatever the style, the screen has to meet the code's opening sizes and the cap has to come off for cleaning. We explain the options that suit your chimney and price them before anything is ordered.

A top-sealing damper as an extra barrier

Some homeowners pair a cap with a top-sealing damper, a damper mounted at the top of the flue that closes the chimney when the fireplace is not in use. It adds a second barrier at the top and is a separate installation from the cap.

Whether it suits your chimney depends on the flue and the crown. We explain the option when it is relevant and price it separately, so you can decide without pressure.