Texas Partners in Flight
Providing and Maintaining New Nesting Habitat
Full Detail of Nesting Tower
Chimney Swift Tower Design Basics
Experimentation with new materials, designs and methods of installation continue. However, several principals are known to work well in wooden Chimney Swift towers.
Heavy texture on the inside is essential. 5/8” Textured 1-11 siding is readily available and easy to work with.
Wooden towers should be double-walled with a space between the inner nest chamber wall and the outer skin. This space should be filled with some form of insulation to prevent overheating. A minimum of 3/4” rigid foam insulation is recommended.
The recommended minimum height is 8’, but 12’ is preferable. The inside diameter should be no less than 14”.
A 24” band of metal flashing around the top is also mandatory. This will prevent predators from being able to climb the tower and gain access to the nest chamber.
The bottom of the tower should be made from 3/4” treated plywood and have a grid of 3/8” holes spaced 1 1/2” apart for ventilation and installed with wood screws for easy removal. The top should be also be made from 3/4” treated plywood and have a opening cut that is no more that half of the area of the inside of the tower. The opening must be placed on the north top edge of the tower to exclude as much summer sun from the nest chamber as possible.
A free-standing tower on steel legs is easier to protect against ants. A 2” band of Tanglefoot (brand) sticky insect trap can be applied around each leg. A concrete foundation will eliminate the need for guy lines. Towers that are 12’ tall will require a 48” x 48” x 10” steel-reinforced concrete slab. Towers that are 8’ tall will need a slab measuring 36” x 36” x 6”. In areas where frost heave is a potential problem, consult local building codes for advice.
In the fall, after the swifts have migrated out of the area, the bottom should be removed and droppings cleaned from the tower. This is a good time to count egg shells and assess the success of the nesting season. Old nests should also be removed at this time. Covering the tower during the winter months will extend the life of wooden towers.
For more information about Chimney Swift conservation , please contact:
Paul and Georgean Kyle
c/o Driftwood Wildlife Association
1206 West 38th, Suite 1105
Austin, Texas 78705