the house detective

buyer challenges accuracy of home inspections

DEAR BARRY: It seems to me that home inspectors often report so-called defects that turn out to be no problem at all. For example, when I purchased my home, my home inspector reported a roof defect that was later refuted by a licensed roofing contractor. The valley in my roof is penetrated by a vent pipe that has sealant but no flashing. The home inspector said this is a defect that could cause roof leakage. The contractor who installed the roof said that vent flashing in a valley is only required in cold climates where snow and ice are prevalent. How can I trust home inspectors, when their reports are so unreliable? Bill

DEAR BILL: Here is some valuable two-fold advice: Find another roofing contractor, and thank the home inspector for alerting you to an important roof defect.

The roofing contractor’s opinion in this case is surprising and unusual because it is a bad practice in general to have penetrations of any kind in a roof valley. All roof penetrations have the potential for leakage, which is why flashing and sealant are always necessary. This is particularly important in a valley because the high volume of water that flows through a roof valley makes leakage worse when it occurs.

The use of flashing at roof penetrations is never an option. It is required in all cases, regardless of climatic conditions, and it is of particular importance in a valley. The very idea that snow and ice are the only forms of weather that call for flashing on pipes and vents is ludicrous. Flashing is meant to keep out all forms of moisture, regardless of whether it is liquid or ice.

Another important aspect of this situation is your automatic assumption that the contractor’s opinion was correct and the home inspector was at fault. Obviously, there are times when home inspectors make mistakes in their findings, and those occurrences should be addressed. However, when opinions between home inspectors and other experts are at odds, it is always best to give each side the benefit of the doubt by seeking further information.

Rather than assuming that home inspectors “report so-called defects that turn out to be no problem at all,” it is always best to seek clarification before passing judgment on an individual or an entire profession. In this case, you might have informed the home inspector that his findings were being questioned. He could then have offered proof of his position or have admitted that he was wrong in his findings. He might have shown you some persuasive evidence from the building code or from the Steep Roof Manual, published by the National Roofing Contractors Association. You might also have consulted your local building department to see whether they allow pipe penetrations in roof valleys and whether they require flashing on all roof penetrations.

When disputes over roofing conditions arise, factual conclusions are important because you don’t want to have a leaky roof.