February, 2004
Inspection News and Views from the American Society of Home Inspectors

NAHB Invites ASHI to Provide Information on Frequently Observed Construction and Product Defects


My favorite form of work is as a consultant to the builder,” says ASHI Member Peter Drenan, president of Building Inspections, Inc., in Charlottesville, Va. According to Drenan, performing this type of inspection reduces customer callbacks and strengthens the builder’s reputation. He explains, “What I care about is helping the community get better homes.”

Networking activities between ASHI and the National Association of Home Builders (NAHB) are motivated by similar sentiments. Most recently, Rich Matzen, ASHI immediate past president, was invited to attend a meeting of the NAHB’s Building Products Issues Committee to share information collected from a group of ASHI members about typical defects or failures they observe in new houses.  

Mike Casey, ASHI past president, first met with this committee in 2002, suggesting ASHI as a source for quality-control information because home inspectors have the unique advantage of being able to observe building products and techniques as they age and endure the local elements. Last year, Matzen presented the results of a Builders Relations Survey, conducted by ASHI to check the pulse of the membership in relation to their interaction with builders, and to identify areas where relations could be improved or enhanced. This January, Matzen was invited back and he took along the results of a follow-up survey.

The 2002 Builders Relations Survey served to identify a group of members who inspected new construction. In December 2003, the same group was invited to comment on the typical failures they observe when inspecting new houses regarding flashing, site drainage, roofs and ventilation. Participants also were asked to list the most frequently observed code violations and the most frequently observed problems due to lack of coordination between the trades.

Although only 10 percent of the 600 who participated in the 2002 survey said they worked for a builder to help improve the product, almost half were willing to take part in the follow-up survey designed to provide information useful for quality control.  

Survey highlights

The participants described the failures they observed in their own words. Here are highlights from each category.

“The most common problem is there is no flashing,” one inspector said in response to the request for examples of improper flashing at doors and windows, and almost a third of the survey respondents agreed. What’s more, windows and doors aren’t the only places where flashing is missing or installed incorrectly. More than 50 percent listed chimneys, roofs and wood decks, and 91 percent said flashing problems were due to installation defects, not product failure.

Site drainage
How many ways can inspectors describe problems with downspouts (73 percent), backfilling (64 percent) and siting (46 percent)? Based on the survey, hundreds. The greatest consistency in identifying a problem was in this category. Almost every respondent described poor execution of one if not all three as typical on home sites. Sixty-seven percent said splash blocks were not sloped away from the house. They went on to describe the problems poor water management causes in crawlspaces, basements and in the house.

One participant declared, “Negative grade is the #1 problem, causing wet basements, mold, bowing walls, cracking windows and sticking doors.”  Another stated, “The 2000 IRC (801.3) calls out gutters and drainage systems in areas with expansive or collapsible soils. These are never installed here, and we have the most expansive soil in AZ. This leads to foundation movement and structural damage.”


When asked about failure of roofing materials, several inspectors mentioned fiberglass shingles cracking and failure of self-sealing shingles to seal, and a few mentioned specific brands. The majority said they were not seeing problems with roofing materials, rather with installation — flashing, nailing, etc. When asked about design, it appears home inspectors most often find fault with valleys.

“Valleys that terminate into walls causing ice damming. Downspouts from higher roofs dumping into these valleys. Lack of clearance at wall-to-roof flashing with siding against the roof. Downspout from higher roofs dumping on lower roofs. Inadequate support and lack of or improper flashing where masonry is loaded on roof framing,” was the description of poor roof design offered by one home inspector.”

Another attributed defects to a “mixture of truss and rafter systems, framed on site, as needed, with whatever materials are available.”

Nailing accounted for the most frequently observed defect in shingle roofs—too few, in the wrong place, overdriven, exposed, seldom done correctly. Problems with felt and flashing were also reported.

The inspectors provided numerous examples of installation and application defects, primarily due to failing to follow manufacturer’s specifications.  
Although inspectors said they occasionally find active leaks, more often they identify defects in order to prevent future problems. And not one thought it was realistic to expect a shingled roof to last 25 years.

The exhaust for the bathroom was the most frequently mentioned ventilation-related problem observed by the survey participants. But attic venting ran a close second, with lack of or improperly installed or blocked vents reported by some inspectors. Vents were most often blocked by insulation, but occasionally paint. When asked about product-related failures, home inspectors most often mentioned attic fans.  

Code Violations
The home inspectors who completed the survey most frequently observed violations of electrical codes. GFCIs were repeatedly mentioned. A variety of violations that could be classified as structural or framing was also cited, as were frequently observed violations of codes covering drainage and handrails. Lack of or problems with weep holes were also mentioned, and numerous other code violations were listed.

Coordination of trades
“The most dangerous of all the trades is a plumber with a Sawzall™,” according to one survey participant. For the most part, the other respondents agreed plumbers are the most likely to be unaware they can compromise the structure and other systems in the house as they complete their part of the job. But other trades were also listed, and lack of supervision was suggested as the reason for most defects.