7. Dress the new portion to the level of the adjacent floor by sanding both areas to a continuous, smooth plane.

8. Dry sweep the area to remove all particles of dust.

9. On open-grained woods, brush on a paste filler. After the filler has partially dried, rub it into the pores of the wood with a circular motion. Wipe the surface lightly to remove any surplus filler. Inadequate filling is indicated by pockmarks and results from wiping off too much of the filler or from unusual absorption by the wood. Eliminate such deficiencies by repeating the filler application.

10. Seal and wax the floor (two coats).

Concrete Floors

Concrete floors should be inspected

annually for dusting, spalling, cracking, and settling. Concrete floors of proper composition, installation, and curing require comparatively little maintenance unless they are exposed to conditions, such as the following:

Severe abrasion and heavy vehicle loads from industrial traffic.

The deteriorating effect of grease, oils, and food acids encountered in galleys, sculleries, and similar food-preparation spaces.

To caustic soaps and solutions.

The corrosive agents in highly acid or alkaline liquids attack concrete floors and cause spalling and pitting. Where trucking is done over concrete floors, such as warehouses, trucks should be fitted with wide-faced wheels; if vehicle abrasion and shock continue to raise maintenance demands, the application of a heavy-duty topping to the concrete should be considered.

CAUTION Do NOT paint concrete floors for functional requirements, such as marking safety lanes or similar areas. Painting for appearance is unjustified and impractical; traffic areas on painted floors will wear first, making the floor unsightly and presenting a difficult cleaning problem.

One of the more common problem areas with concrete floors is the development of unsightly cracks. Cracks in concrete floors maybe caused by shrinkage, temperature changes, settlement, or lack of rigidity of supporting beams or other structural members. When such movements are recurrent and can be eliminated only by major structural changes, little can be done except to keep the cracks filled with a mastic material. In many cases comparatively small cracks may be filled with varnish or resin. Although the cracks will remain visible, they will not leak or gather dirt. When the cause of larger cracks has been determined and corrective measures taken to eliminate further cracking, the cracks can be permanently repaired by filling them with nonshrinking cement mortar.

Patching will not permanently correct cracks in slabs on grade caused by vertical movement resulting from exceeding the design load of the slab, inadequacy of the base, or insufficient bearing capacity of the soil. Slab failure under these circumstances can be corrected only by a major maintenance operation, such as mud-jacking. The procedures applicable to the repair of concrete floors are covered in detail in the section of this chapter that deals with the maintenance and repair of waterfront structures.

Terrazzo Floors

Terrazzo floors should be inspected annually for loose or broken segments and damage from improper cleaning. Terrazzo appears to be dense and very hard, but the cement is sensitive to harsh soaps and cleaners, which can cause pitting, roughen the surface, and make the floor permanently susceptible to dusting and dirt trapping. Repairs to a terrazzo floor should be made according to the specification for new floors. Only floor specialists who are capable of the class of workmanship necessary should be entrusted with the work.

Clay Tile Floors

Clay tile floors should be inspected annually for missing loose, or broken tiles; open joints; and damage from improper cleaning. If floor damage requires replacement of broken or badly stained tiles or resetting loose tiles, the steps for the procedure are as follows:

1. Remove the damaged or loose tiles.