Home-buyers often worry that having a home inspection in the rain will lead to a lower quality inspection. The obvious concern is that because of the rain, the inspector will not be able to see certain defects or access certain areas of the home.
That’s a possibility, and there are absolutely times when at a minimum; the exterior portion of the inspection has to be re-scheduled due to the volume of rain.
The inspector may recommend that all of the interior portions of the home include the attic(s) undergo assessment and then a return trip be scheduled. If you, the home-buyer, are in an option period, dividing the inspection like this allows you more time for due diligence.
But light to moderate rainy days shouldn’t prompt you to cancel your home inspection if you are in an option period. I think the risk of losing due diligence days while trying to find another inspection company (some home inspection companies may not be able to get them back on their schedule) is too high to warrant a cancellation.
I also don’t believe that there is a reason to worry, as long as you found the best home inspector available, you will still get a high-quality inspection. In my opinion, inspecting a home during light to moderate rainfall is a bonus. To help explain that statement, I’ll provide a list of common questions that I’ve answered which will help explain the pros and cons.
How does the rain typically affect the inspection of the roof system?
PRO’S: Inspecting in the rain helps inspectors find new leaks and shouldn’t prevent them from finding old leaks. New leaks are water leaks that can only be found from within the attic when it is raining, or during a thermal imaging inspection. Once the rain quits and the water dries, new leaks leave no evidence of their existence.
I have one example of a new leak I can share from a previous home inspection that I conducted in the rain.
I was inspecting an attic, looking around the base of the plumbing vents, exhaust vents, etc, for signs of water damage. On this rainy day, I spotted water rolling down a Polyvinyl chloride (PVC) plumbing vent. I followed the dripping water up to the roof decking penetration and I could just barely see a gap between the vent and rooftop flashing.
The leak was very new and had not yet damaged the attic floor decking, so I used a moisture probe to document and record the roof leak.
I performed a thermal imaging scan of the garage ceiling, the imager could not detect the leak because it was collecting on the attic decking, and not affecting the garage ceiling in any measurable way.
Had I inspected a few days after the rain, there would have been no stain on the decking from the new leak, and I would have been none the wiser.
Over time, the gap between the vent pipe and gasket would have increased, allowing a bit more water infiltration. The damage would eventually show on the garage ceiling, prompting repair. Also, roof leaks are typically a relatively low-cost home maintenance repair. It takes time and poor or delayed maintenance practices by homeowners before most roof leaks start significantly damaging the structure.
It’s also important to remember that most leaks are observed from within the attic and home; rain won’t affect access to those locations.
CON’S: Rain can limit access to the roof and can make it difficult to accurately assess some components. For instance, the roof is less likely to be walked if it is steep due to the water and the inspector may have trouble accurately dating the age of the shingles (wet shingles mask granule loss and color deviations, which are key identifiers).
I think every inspector should walk the roof when it is safe to do so. But I think they should walk it to get their hands on the shingles to better assess the aggregate, test shingle adhesion at common trouble spots, and to make sure that there are no MISSING WALLS (this happened)!
How does the rain typically affect inspecting the Grading, Drainage, & Gutters?
There’s no better time to evaluate your lots ability to divert surface water than when there is a torrential downpour of rain. If streams of surface water are being routed onto the rear patio of the home, your inspector will have an easy time documenting the problem.
Even more, she may spend more time evaluating the interior and exterior of the house at the floor level for signs of partial flood damage.
Conversely, if that same home was inspected during a dry spell, there may not be any evidence that large volumes of water have been collecting onto the rear patio and had flooded the home.
If a dishonest seller decides to make a few “cosmetic” upgrades, the inspector won’t have any observable evidence that there was a problem.
I hope you enjoyed the read, and I hope this prompted you to take advantage of the rain. Even if you’ve had your home inspected recently, it would be beneficial to observe your attic during a moderate to heavy rain.
Stay tuned for my future articles regarding how to check your roof, and how to do a personal thermal scan; along with what imager for periodic preventative maintenance.
I may earn a small commission for my endorsement, recommendation, testimonial, and/or link to any products or services. Your purchase helps support my work in bringing you real information about predictive home maintenance and building science. You can read more here.