That plaster base or other surfacing or panels and trim are carefully and accurately installed so that a neat, workmanlike finish is obtained. When necessary, make sure that all fastenings are completely concealed behind the trim and that the latter is nailed with finished brads.

Wood Roofs

You may have occasion to inspect various types of roofs, including concrete, corrugated metal, wood, and so on. Although this chapter is broad in scope, it does not cover all the different types of roofs. The subject matter is limited to wood roofs.

When a pitched roof is inspected, you, as the inspector, must ensure the following:

That all framing is cut accurately to exact length. It must be beveled or mitered as necessary to assure proper bearing of the cut at all meeting faces, and it must be securely nailed.

That all bracing, trusses, collar ties, king post, and end studs are provided according to the drawings and specifications.

That sheathing is laid tight and straight and that it is nailed according to the specifications. You should be sure that sheathing on pitched roofs is started at the eaves, with the face grain laid perpendicular to the rafters and with the horizontal joints staggered at mid-sheet intervals.

Thickness of plywood is very important to any roof, and this is where local codes tend to differ due to load design, wind resistance, or type of roofing material. Normally 1/2-inch plywood is the minimum; however, 7/16-inch oriented stranded board (OSB) is widely used in residential construction.

THERMAL AND MOISTURE PROTECTION

The material and its installation, used in thermal and moisture protection, is critical to any construction. In the construction industry, insulation is usually thought of in relation to heat transmission, although sound is an equally important item to consider. There are so many different types of thermal and moisture protection, such as waterproofing, dampproofing, vapor and air retarders, fireproofing, various types of insulation (blanket, batt, and loose), and joint sealers. However, with limited space, we will briefly cover waterproofing, building insulations, and joint sealers.

Waterproofing

Waterproofing is the material used that results in the protection of an area, structure, or individual member from the presence of water, whether it is in the form of a liquid or a vapor.

Membrane waterproofing is achieved by the placement of a moisture-impervious membrane, such as bituminous membrane (felt paper), polyethylene (plastic), or sheet rubber. When a membrane waterproofing material is applied to a surface, that surface must be clean and free from foreign material and kept dry. You must ensure quality workmanship and proper installation procedures are strictly followed.

Insulation

Insulation materials are resistant to the passage of either heat, and sound, or both. Typical insulation materials include the following: foamed glass, foamed plastics, glass fibers, cork, asbestos fibers, and granular fibers, such as vermiculite and perlite. Insulating materials are often designed to trap dead air space.

Before the installation of these materials, make sure that no moisture has damaged the material due to handling or transporting. Again, adhere to quality workmanship during installation.

Fiber glass (blanket, batt, or loose) must be inspected for the approved manufacturer's specifications for the proper R value and thickness. Fiber glass is usually covered on one or two sides with either a paper backing or foil backing or wrapped with a plastic wrap. It also may be blown in loose.

When fiber glass insulation is inspected, make sure that the proper procedures are followed according to the specifications or manufacturer's specifications. In the construction industry today, "fiber glass" is treated almost like "asbestos." Check with your safety officer or environmental officer for the proper handling techniques.

In masonry construction "vermiculite and perlite" are excellent sound-proofing insulation to fill all the hollow cores that are not already filled by concrete. Vermiculite and perlite are also used as an additive to plaster or joint compound to texture the ceilings and sound proofing.

Joint Sealers

The purpose of joint sealers (caulking) is to obtain a watertight structure. In masonry walls, a space about