DOUBLE-UNIT HOUSE 131 
When the house is completed, a concrete floor should be laid, 
and should consist of three or four distinct layers. First, a layer 
of about six to ten inches of cinders or coarse gravel, tamped 
thoroughly. This serves for drainage purposes to keep the soil 
moisture away from the bottom of the floor. Next, a rough coat 
of concrete about four inches thick, and over this a finished coat 
of two parts of sand with one of cement, trowelled smooth. 
Where there is danger of much moisture coming up from below, 
it is advisable to put a layer of tarred building paper between the 
rough and finish coats of cement. It should be nailed down with 
a 
Fia. 85.—Double-unit house completed. Note the combination door and window, 
and the arrangement of openings for light and ventilation. 
flat-headed nails; the heads of the latter should be left sticking 
out about one-quarter of an inch to hold the top coat of cement. 
Such a floor is moisture proof and vermin proof, and is easily 
and quickly cleaned. 
The completed house is shown in figure 85. 
Materials—In the following list of materials required for 
building a double unit, as shown in the working drawings given in 
figure 83, the prices quoted are only approximate: 
LumsBer: SGills......... bee denied Gis la maint Grate 6 ps. 4” x 6” x 20’ 
Plates: 2.0. aesvaigd eee sheet eee oe te 8 ps. 2” x 4” x 20’ 
PORES Sj coideeos eee eee ea Ok RS OS 2 ps. 4"x 4” x 14’ 
2 ps. 4” x 4" x 18’ 
Studdings cers vanes ckeia seesaw 9 ps. 2”x 4" x 18’ 
. 4 ps. 2”x 4" x 14’ 
RAfEGTS gags oaceeee h ea Gee Gas DEES eee eek 22 ps. 2” x 4" x 22’ 
Frame for nests and dropping boards...... 5 ps. 2” x 3” x 16’ hemlock. 
Roof, dropping boards, walls, and nests, 8-mch tongue-and- 
groove boards 5. ..s.sae voy jes eve aumgaermist es paaee sex 2,200 sq. ft. 
Curtain frames and trim, 1” x 2” white pine............ 200 linear feet 
