Checking for Hidden Water Damage

Leak in roof running down rafter.
Leak in roof running down rafter.

We are in the process of purchasing a new home, but it has a strong damp/musty odor. How can we make sure it has no water damage? -Raul


There are a number of possibilities that could be causing your problem including a leaky roof, plumbing leaks, excessive moisture in the crawl space, a slab that wasn’t waterproofed correctly, condensation in the walls due to an improperly installed vapor barrier, or damage from flooding.

While it’s not easy to check inside of walls, you can inspect the attic as well as under the house or in the basement for signs of leaks, moisture buildup, mold, or rot. A moisture meter can be used to check for excessive moisture in wood while a hygrometer can determine the moisture content of the air.

Water stains on rafters are a telltale sign of leaks, either past or present. Also, be sure to examine the floor joists under the house for signs of mold. If the house is in an area prone to flooding, look in out of the way places—like closets and inside of cabinets—for stain lines on the walls or water damage on the floor.

I would definitely have a competent home inspector examine the house before you purchase it, as mold and excessive humidity can be costly to eliminate.

Check out our articles How to Prevent and Remove Mold and Attic and Basement Frequently Asked Questions for more information.



  1. I’ve heard of a thermal-imaging device that can actually check for mold inside of walls…Usually done by a professional company, I’m sure.

  2. Danny,

    I hung a wooden clothes rack over my waher and dryer. I used molly bolts on each of the plastic inserts that supported the wooden pole.
    My problem is that one of the plastic insert broke and the molley bolt is still in the sheetrock. Now I need to put up another insert.

    Can you please tell me what to do.

    Thank you



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