How to Identify Dry Rot

How to Identify Dry Rot. Dry rot, also known as brown rot, is a wood-destroying fungus that affects soft and hard woods. Mostly found in damp and humid conditions, dry rot depletes the moisture from dry wood, sometimes causing extensive structural damage.

If not identified early, dry rot seeps through bricks and mortar to wood located in poorly ventilated areas. It cannot affect the masonry but dry rot strands carry the moisture needed to spread.

  1. Search for wood that is sunken or shrunken.

  2. Determine whether the affected area is black and covered in mildew.

  3. Look for affected wood that has flat "skin-like" growth. The skin may have a mushroom-like growth with shades of silver and gray. It may be patterned with patches of light purple or yellow and peels easily.

  4. Check wood with damp and musty odors. Watch for white "cottonball" growth on the wood. This is very important if you suspect water damage.

  5. Examine any dust around the rotted area. Dry rot dust is a rust red color.

  6. Inspect any area with wide, soft and fleshy wide spores. The spores may have an orange and green surface. Look for thick gray strands, up to three millimeters in diameter, growing within the cracked section of wood. These strands may be found alone with out any other symptoms of dry rot. The strands make the wood brittle and crack easily and can grow over other damp wood, possibly leading to dry rot.

  7. Verify dry rot with an ice pick inserted in the middle of the affected area. If it goes through the wood easily, you have may have dry rot. If the wood seems solid and dry, you may not have any major problems with the wood. However, you should look for cracks and rips in the wood that are susceptible to water damage.

  8. Tip

    Purchase dry rot sensors to test for dry rot. Contact a professional wood treatment company if you suspect dry rot.


    Do not ignore symptoms of dry rot.

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