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Dry Rot Damage To Crawl Space Wood

Dry rot damaged wood in a basement floor joist

Dry Rot Damage

Dry rot damage can severely weaken affected wood.

In fact, the USDA Forest Service reports that just a 1% decrease in the weight of dry-rot-damaged wood can lead to a 75% loss [PDF] of its the wood's toughness.

Dry rot (or brown rot) is a common name for a number of species of rot that create a dry, cracked appearance on wood.

Dry rot has earned its name from its ability to pull moisture from damp areas to dry ones. It can pull this moisture through mortal, concrete, masonry, and even from behind plaster, allowing it to thrive in conditions that are too dry for other types of rot.

Dry rot spores are present in most homes, and can survive for several years, until the conditions to grow are right.

How Damaging Is Dry Rot?

In the United States, dry rot has been credited with causing damages costing approximately 20 billion board feet -- or about $17 billion dollars annually.

Replacement of rot-damaged wood accounts of almost 10% of the annual wood production of the United States -- far more than is destroyed by fire!

Get a Free Estimate

Many Basement Systems Dealers offer services that include removing and repairing wood damaged by rot in crawl spaces and basements. Our dealers can also provide warrantied structural repairs and moisture control systems for crawl spaces.

It costs you nothing to meet with one of our specialists for a free, no-obligation crawl space repair estimate! Our network of more than 300 certified dealers serves throughout Canada and the United States! Contact us by phone or e-mail today to get started!

A crawl space contractor installing a waterproof vapor barrier system on the foundation walls

Sealing Your Crawl Space

Dry rot needs moisture too! Despite its common name, it needs 28-30% moisture content within the wood, with a relative humidity of 95% or higher, to produce mold spores.

Most softwood timbers in dry homes, particularly in upper levels, have a 12-15% moisture content.

Sealing off your crawl space doors and vents, installing a vapor barrier on all wall and floor surfaces, and running a powerful crawl space dehumidifier can bring moisture levels below what dry rot need to thrive.

More about Sealing A Crawl Space

What Dry Rot Damage Looks Like

Dry rot damage reduces the wood to crumbling, rectangular pieces on the surface. Due to its appearance, this type of damage is often mistaken for a termite infection.

A common early warning sign of dry rot is the appearance of rust-colored "red brick dust". This dust is actually an accumulation of fungal spores covering the surface of the wood.

Dry rot outbreaks occur most often several months after a household flooding event.

Four examples of dry-rot-damaged wood:

(Click to see larger view.)

Wood showing severe signs of dry rot damage Painted wood that is badly decomposed by dry rot.
Old, dry wood that is showing extensive dry rot damages A decomposing crawl space floor joist showing extensive dry rot damage

Steps To Eliminate Dry Rot & Repair The Damage

Before repairing drywall damage and/or replacing affected wood, you should address the moisture problem that is keeping dry rot alive.

Remove all sources of standing water, and install a waterproofing system if the space is flooded. Install a powerful, self-draining, energy efficient dehumidifier to maintain the dry environment. If you're repairing a moldy crawl space, encapsulate the area with vent covers, and airtight door, and a crawl space liner.

If these steps are not taken before the repairs are made, the conditions may be right for dry rot to begin growing again on the newly replaced wood.

  1. Remove Rot-Affected Wood: All wood that shows signs of decay or visible fungus should be removed. As a precaution, you should also remove and replace all wood within one meter of the affected area.

  2. Remove Organic Materials Near Damaged Wood: Building materials that contain organic food for mold should also be removed and replaced, including plaster, drywall, fiberglass insulation, and wood paneling.

  3. Clean Nonporous Surfaces: Using a stiff wire brush, clean off all nearby surfaces, including metal and pipes, within 1.5 meters of the furthest edge of the infection. All dust and debris should be carefully cleaned up after the work is done.

  4. Kill All Remaining Fungi: It's a good idea to apply a fungicide to all masonry, concrete, and exposed organic surfaces in the area. A second coating should be applied to any wood surfaces within 1.5 meters of the damaged area.

  5. Rebuild The Structure: Repair and replace all areas where damaged wood was removed.

We Specialize In Crawl Space Repairs Of All Types!

At Basement Systems, we specialize in creating healthy, well-maintained crawl space environments. Our complete crawl space system will keep your crawl space dry and energy efficient, helping you to control mold, rot, humidity, and mildew within the space. We also perform structural repairs to crawl spaces, and many of our experts offer services in repairing and replacing rot-damaged wood.

Our warrantied systems have been successfully installed in hundreds of thousands of homes worldwide! To schedule a free, no-obligation crawl space repair estimate to find out how we can help you, contact us by phone or e-mail today!

There's a authorized Basement Systems Dealer in your neighborhood! Our locally owned and operated contractors operate throughout Canada and the United States. We're standing by to help you!

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Our innovative and forward-thinking approach to designing products has solved wet basement problems that the basement waterproofing and crawl space industry has faced for decades, and our patented sump pump systems are the smartest and most reliable. Plus we listen to our customers and respond accordingly! Basement Systems Inc. has been awarded 24 Patents and 19 Innovation Prizes on waterproofing products we use every day, including a battery back up sump pump system. This approach ensures the best waterproofing systems and solutions available.