House Improvement

House improvement consisted of putting in a solid concrete foundation that would not crack, plastering the inside and outside adobe walls to cover existing cracks, whitewashing the walls with lime, installing glass windows and metal screening, tiling the roof, and installing a ceiling to the interior. Bedrooms were first improved; later, dining and storage rooms. Depending on the condition of their houses, some families decided to demolish and reconstruct them, sometimes adding additional rooms, especially bedrooms. These improvements eliminated common nesting areas for triatomines. PBCM allotted supplies progressively in order to provide an incentive to complete each task and receive the next supply. Thus a temptation was removed to misallocate the materials. Households preferred to do the more favorable tasks first and neglected the less desirable, such as improving the surrounding area.

^{Figure 24a.}

^{House before improvement. A family standing in front of the remains of their previous house that had been infested with vinchucas. (Photograph by Joseph W. Bastien)}

^{Figure 24b.}

^{A community health worker distributing building supplies. (Photograph by Joseph W. Bastien)}

^{Figure 25a.}

^{A neighbor helping mix plaster for walls. Exchange of labor is done through the concept of aynisiña. (Photograph by Joseph W. Bastien)}

^{Figure 25b.}

^{A man hammering stones between the adobe blocks of his house to prevent entry of bugs. (Photograph by Joseph W. Bastien)}

One criticism of PBCM is that for the first 400 homes it did not improve peridomicile areas, and, when they were evaluated, vinchucas were found in these areas. By 1992, however, bug‑proofing of peridomicile regions became part of the program. The strategy was then adopted of starting with the peridomicile; if this was improved, then material was supplied for the house. This way both corrals and houses were bug‑proofed.

Traditional methods and available resources were used together with more innovative techniques, tools, and materials whenever possible. Sand, earth, and cow dung were collected locally to make wall plaster. Workers prepared the lime by heating locally collected limestone rocks in an open kiln for twenty‑four hours and then pulverizing the residue with a hammer. After plastering, they applied a white paste of lime and water to the walls to improve the appearance.[55]Wall plastering substantially reduces vinchuca infestation; but to be successful it has to be done thoroughly, so as to seal all the cracks and crevices in the house walls. The use of slow‑release insecticide paints is another preventative measure.[56]

PBCM also taught villagers to make ceramic tile roofs to replace thatched roofs, greatly reducing a popular infestation area for triatomines. One community mastered tile making and began marketing their tiles to neighboring villages, thus developing a small local industry. Low‑cost roofing material is needed in developing countries to provide a substitute for corrugated galvanized iron roofing, which is very noisy when it rains and heats up when it is hot, both common conditions in the tropics.[57]Sheet roofing also is extremely dangerous in windy climates when it becomes stripped from the house and is sent hurtling through the air with its sharp edges.

A stable concrete house foundation is necessary for each house to prevent water damage to the base of the walls and floor. Cement is expensive in terms of both price and transport costs, but a durable local substitute material was used in Chuquisaca. Soil stabilization was achieved by increasing the cohesion of the soil.[58](This is one area where technical assistance is helpful.)

^{Figure 26.}

^{A woman and her children standing in front of their house after its improvement. (Photograph by Joseph W. Bastien)}

As an alternative, not utilized by PBCM, the mechanical compaction of adobe mix greatly increases its stability. An adobe press with a long handle used as a lever to compress the mud and clay in molds provides more leverage than the customary force of chest and arm muscles and results in a much harder adobe (Lunt 1980, Webb 1985, Webb and Lockwood 1987).[59]