& Nest Boxes
The 14 degree roof angle used in
50birds Birdhouse Plans
corresponds to what framers and roofers often refer to as a "3:12 pitch"
- 3 inches or feet of rise to 12 inches or feet of horizontal length. A
3:12 pitch then is the same as 1:4 pitch, one inch of rise to 4 inches horizontal
distance. Knowing the 1:4 relationship between rise and length,
one can easily determine the rise on any side panel using the floor
The height of the back edge
of a side panel of 4" width (equal to floor widths), is exactly one inch
greater in height than the front edge (one quarter inch rise for each inch
of width). A side panel of 5" width differs from front to back by 1
1/4", one of 6" width rises 1 1/2" front to back, and so forth.
The inside height of the front panel is
identical to the front edge height of a side panel. Power saws can then be set at 14
degree angles (roughly, it's not critical) and cuts made following a pencil marked line on
the long edge (inside), of the front panel (front panel has the entrance
Once a woodworker
fabricates a few nestboxes based on this convention,
the dimensions of any one of 25 models can be arrived at knowing only the floor size and
inside front ceiling height, which are coded into the nestbox model numbers. Find free
printable woodworking plans for these and more 50birds birdhouses in the Models Index.
a floor dimensions
b inside front floor to ceiling
c inside floor to top of hole
d hole dia. ex: 112 = 1 1/2"
1916 = 1 9/16"
Finer dimensions such as plus
13/16" on the opposite side (front height of the front panel), do not
have to be measured. If the saw angle is reasonably close to 14
degrees, and if the inside height is measured, marked and cut reasonably
close, the finished panel will serve its purpose.
Tolerance on a bird house
which needs ventilation is not very critical. Mistakes, crooked cuts,
gaps, etc. may be a good thing. Where panels are square, rectangular and
cut at right angles (90 degrees), where precision is easiest to accomplish, good fit and
fastening make for a sturdy box and a secure home.
Dimensions such as 31/64" are not
meant to indicate the need for low tolerance. They are just precise computer
calculated dimensions and arrived at when the opposite side of a panel, 5/8" or
3/4" thick, is cut at a 14 degree angle. Use them as dimensions to check,
before cutting, after cut lines are drawn, or just ignore them. The measured
dimension is on the opposite side where the cut line is drawn. Neither is
critical. In fact, it might be best, depending on climate and sun exposure to cut
the front panel 1/2" or 3/4" short to provide extra ventilation.
For simplicity, move to the next larger
increment. For example, 31/64" can be adjusted to 32/64", which is the
same as 1/2". Similarly, 13/16" can be thought of as between
3/4" and 7/8", plenty precise wood working for bird houses.
You may wish to cut larger portions out of
the floor and side panel corners than plans specify or drill holes for more ventilation in
Hinges are suggested for easy access.
Other methods for attaching roofs are just as good or better. However, most nest
boxes are mounted out of reach for most people. Bird house mounting, monitoring
and maintenance on ladders is an awkward chore that requires three hands. The
convenience of hinges increases safety.
Materials are not critical. Cedar is
nice. It is often rough cut, or simulated, which is good for grip, and it
endures. When fresh, it has a repelling effect on some insect pests. Pine will
3/4" stock is the most common. 5/8" stock where called for can
be supplied with fencing material from most lumber yards (5/8" stock is used on the
smaller nestboxes because 3/4" stock makes them look odd).
Bone piles from new
fences or home construction sites are good sources for the small sizes
usually called for. You shouldn't have to pay for any if you
keep your eyes peeled.
Hardwoods are difficult to work with unless
fine joinery is used. It's more work and not necessary.
The wood layers of plywood will peel eventually as moisture will
degrade a glue's adherence qualities. Plywood may be the best choice where
large panels are required for example: in a Barn Owl box or one of the larger nestboxes
for Ducks, Barred Owl and Pileated Woodpecker.
If you use plywood, paint the edges. Resources