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Wood Rot: A Common Crawl Space Moisture Problem

When moisture enters your crawl space, it can cause the wooden supports to rot or decay.

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We all know that wood decays when it comes into contact with water. That’s not an issue for many homeowners. But if this happens inside the crawl space of their Raleigh or Winston-Salem homes, it becomes a different story.  

Wood-eating fungi can attack and weaken your crawl space supports and wood joists. Repairing them isn’t going to be cheap. You’ll be lucky if you get away with sanding your wood to remove residual fungi. If the wood supports have rotted, you’ll have to replace them and this can set you back several thousand dollars. 

Let’s go over the types of wood rot, signs, causes, and prevention tips.  

rotting wood

What Is Wood Rot? 

Wood rot is a form of decay that occurs when specific bacteria digest the cellulose fibers that give timber its strength and form. Moisture has to be present for the bacteria to attack the wood. 

Types of Wood Rot 

Wood rot can be categorized into wet and dry rot. It’s important to understand both, so you know what you’re dealing with. 

Dry Rot 

One of the most damaging forms of fungal decay, dry rot, attacks and digests the fibers that give timber its strength. This can weaken timber and lower your building’s structural integrity.  

Unlike wet rot, this type doesn’t require moisture. It also spreads fast. Within a short time, the wood-attacking fungi can destroy a large portion of building timber.  

Signs of Dry Rot 

  • Distinct mushroom smell 
  • Deep cracks that run across the wood grain 
  • Whitish residue known as mycelium growth 
  • Lemon-yellow or lilac tinge  
  • Crumbling wood 
  • Large flat mushroom-like fruiting bodies growing on your paint or plaster 

Wet Rot 

This type occurs in damp conditions where moisture levels are above 50%. A burst pipe, wrongly-fitted plumbing, and condensation are all potential sources of moisture that can induce wet rot. 

Signs of Wet Rot 

  • A dark fungal patch or stains on your timber 
  • Wood is soft and spongy to the touch 
  • Wood becomes brittle or starts crumbling 
  • Damaged, flaky, or bubbling paint finish 

What Causes Wood Rot? 

Moisture is often the major culprit and it can arise due to poor ventilation, plumbing leaks, or condensation. Leaks on the roof, penetrating moisture, and blocked gutters/downspouts are other sources of moisture. Your plumber or crawl space contractor can help you uncover the sources of wood decay. This way, you’ll be able to take appropriate action before things take a turn for the worse. 

How to Repair Wood Rot 

If you already have wood rot in your home, check to see if you can salvage the timber. You need to remove the rotting part. If the damage is significant, such as the entire door frame, you have no other choice but to replace it. Ensure that the carpenter applies a wood hardener that penetrates the wood fiber to give it added structural strength. 

Preventing Future Wood Rot Problems 

When it comes to dealing with wood rot, prevention is better than a cure. It’s much cheaper to stop wood rot than to replace rotted wood. To curb wood rot, eliminate moisture and there’ll be no fungi to attack it. Contact a crawl space expert if you’re having problems locating moisture sources. 

Your local contractor will seal all the cracks in your foundation walls and then cover your crawl space walls and floors with a thick 20-mil plastic vapor barrier. This will cut off moisture and underground water that may cause problems. If moisture levels are through the roof, you will have to install a dehumidifier to dry out the crawl space air.   

If you are concerned about what wood rot might do to your crawl space beams or joists, contact Tar Heel Basement Systems to request a free crawl space inspection and repair quote. We’ll assess the crawl space, perform the necessary repairs, and then seal it up so it stays dry. 

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