Editor'snote: This story is adapted from the U.S. Department of Housing and UrbanDevelopment's Residential Rehabilitation Inspection Guide, 2000. Clickhere for other stories in this series.
After the site inspection has been completed, systematically inspect thebuilding's exterior for its condition and weather-tightness. Begin either atthe foundation and work up or begin at the roof and work down. Examine thequality and condition of all exterior materials and look for patterns of damageor deterioration that should be further investigated during the interiorinspection.
Exterior wall cladding
Exterior walls above the foundation may be covered with a variety ofmaterials, including wood siding or its aluminum and vinyl substitutes, wood orasbestos cement shingles, plywood with and without a medium density (plastic)overlay, stucco, brick or stone masonry, and an exterior insulation and finishsystem.
These materials are designed to serve as a weather-tight, decorative skinand, in warm climates should be light in color to reduce heat absorption.Inspect exterior claddings as follows:
- Exterior wood elements. Inspect all painted surfaces for peeling, blistering, and checking. Paint-related problems may be due to vapor pressure beneath the paint, improper paint application, or excessive paint buildup. Corrective measures for these problems will vary from the installation of moisture vents to complete paint removal. Mildew stains on painted surfaces do not hurt the wood and may be cleaned with a mildew remover. All wood elements should be checked for fungal and insect infestation at exposed horizontal surfaces and exterior corner joints. Check the distance between the bottom of wood elements and grade. In locations that have little or no snow, the distance should be no less than six inches. In locations with significant, lasting snow, the bottom of wood elements should be no less than six inches above the average snow depth.
- Aluminum and vinyl siding. Aluminum and vinyl siding may cover up decayed or insect-infested wood but otherwise are generally low maintenance materials. Check for loose, bent, cracked, or broken pieces. Inspect all caulked joints, particularly around window and door trim. Many communities require aluminum siding to be electrically grounded; check for such grounding.
- Asbestos cement shingles. Like aluminum and vinyl siding, asbestos cement shingles may cover decayed or insect-infested wood. Check for loose, cracked, or broken pieces and inspect around all window and door trim for signs of deterioration.
- Stucco. Check stucco for cracks, crumbling sections, and areas of water infiltration. Old and weathered cracks may be caused by the material's initial shrinkage or by earlier building settlement. New, sharp cracks may indicate movement behind the walls that should be investigated. It is difficult to match the color of stucco repairs to the original stucco, so plan to repaint surrounding stucco work where sections are mended.
- Brick or stone veneers. Inspect veneers for cracking, mortar deterioration, and spalling.
- Exterior insulation and finish systems (EIFS). EIFS, also known as synthetic stucco, has been in widespread residential use since the early 1990s. It generally consists of the following product layers (moving outward): insulation board, mesh and base coat layer, finish coat, and sealant and flashing. EIFS was originally designed as a non-draining water and moisture barrier system. A drainage-type EIFS that allows water and moisture to penetrate the surface and then drain away has been developed more recently. Most existing EIFS in residential applications is installed over wood framing and is of the non-draining type. Water leakage and consequent rotting of the wood framing have become serious problems in many installations, especially at wall openings such as windows and doors, where inadequate flashing details can allow water seepage into the wall interior. Manufacturers of EIFS differ in their installation methods. Inspecting existing EIFS is difficult because it is a proprietary product and there are no standard construction details. Use a trained specialist to check for concealed water damage and rot.
Exterior walls of older buildings usually contain no thermal insulation.Examine behind the cladding when possible to determine the presence ofinsulation, if any, and assess the potential for insulating the exterior walls.Where mildew and mold are evident on exterior cladding or where interior wallsare damp, there is the possibility that condensation is occurring in the walls.Moisture problems generally occur in cold weather when outside temperatures andvapor pressures are low and there are a number of water vapor sources within thebuilding. The presence of moisture may be a result of an improperly installed orfailed vapor barrier, or no vapor barrier at all. If condensation is suspected,an analysis of the wall section( s) in question should be made. This analysiswill provide the information necessary to make the needed repairs.
Other outside inspection areas:
- Determine the building's architectural style and note what should be done to maintain or restore its integrity and character. In regions of medium to high seismic activity, buildings with irregular shapes (in either plan or elevation) may be especially vulnerable to earthquakes. Examine the building for such irregularities, and if present, consider consulting a structural engineer. In hurricane regions, examine screen and jalousie enclosures, carports, awnings, canopies, porch roofs, and roof overhangs to determine their condition and the stability of their fastenings. Then examine the following four critical areas of the exterior to determine their condition and strength: roofs, windows, doors, and garage doors. In locations where wildfires can occur, some jurisdictions have restrictions on the use of flammable exterior materials. Check with the local building official or the fire marshal, or both, for detailed information.
- Foundation Walls and Piers. Foundation walls and piers in small residential buildings are usually made of masonry and should be inspected for cracking, deterioration, moisture penetration, and structural adequacy. Wood posts and columns and concrete foundations and piers should be inspected.
- Skylights. From the exterior, check all skylights for cracked or broken glazing material, adequate flashing, and rusted or decayed frames. Skylights will be checked again during the interior inspection. Leaking skylights are common. Replacement skylights must comply with the building code.
The Old House Web