B4388M
Figure 19.—Defects in foundations, such as the opening to the right of the step, are often the cause of rat infestation in old buildings
All openings between floors and in partitions made for the passage of pipes and wires and any defects in the wall should be closed with metal flashing. All dead spaces throughout the building, such as boxed-in plumbing, spaces behind or beneath built-in cabinets, counters, shelving, bins, show windows, and many similar places, should be removed, opened up, or effectively and permanently proofed against rats.
In the Southern States, where the roof rat occurs, similar care must be taken to make the upper floors and roofs of buildings rat proof, as this rat is an expert climber and frequently enters buildings by way of the roof. Doors at the top of stairs and elevators should fit snugly, and all ventilators, exhaust fans, unused chimney flues, and other openings should be screened. Broken skylights and openings under eaves and places where electric wires enter the building should be repaired or closed.
Figure 20.—Methods of rat proofing stud spaces in old buildings: A, Construction at outer wall. Open stud spaces are filled with weak concrete, which is placed by removing the skirting above. If the work is done a little at a time, the wooden forms can be removed when the concrete has set, and used again. B, Another method employing sheet metal secured to sill, joist, and flooring. C, Post and girder in basement supporting partition with open stud spaces. Sheet metal nailed to joists and floor and fitted about the stud prevents access to upper floors
