How to Repair Dry Rot in 4 Simple Steps

Wood plus water doesn't have to equal your worst nightmare

side of home with rotten window frame
Photo: NanSan / Adobe Stock
side of home with rotten window frame
Photo: NanSan / Adobe Stock
SKILL LEVEL
Intermediate
COMPLETION TIME
5 hours
COST
$25–$50
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What you'll need:
TOOLS
  • Wood chisel
  • Wire brush
  • Foam brush
  • Putty knife
  • Safety goggles
SUPPLIES
  • Epoxy wood hardener
  • Wood filler
  • Sandpaper

Don't be fooled by the name—dry rot occurs when there's a lot of moisture around the wood in your home. Excessive moisture creates the ideal conditions for the fungus species that causes dry rot to thrive, putting your home's wooden features at risk. Knowing how to repair dry rot—and how to identify it in the first place—can help you protect your property for years to come.

Prepping to Repair Dry Rot

man using paint scraper
Photo: Ben-Schonewille / istock / Getty Images

Before you can stop wood rot, you have to know what you're looking for. So, what does dry rot look like? Some common signs of it include:

  • Peeling paint or blistering

  • Discolored or darker wood

  • White or gray mold spores

  • Green algae-like growth

While dry rot strikes wood first and often occurs around windows or doors, it can spread to your home's mortar and plaster if left unchecked.

How to Repair Dry Rot

rotten wooden door
Photo: Ionut Ciocan / istock / Getty Images

You can repair small sections of dry rot on your own. For larger areas, your best bet is to call in the help of a professional who fixes dry rot. This is because the repair may require removing and replacing entire sections of the wood. In extreme cases, the structural integrity of your home may be in jeopardy, which is something a professional must address.

  1. Find the Cause

    First, find the cause of the rot and fix it before you repair the damaged area. Common causes of dry rot include:

    • A roof leak

    • Lack of ventilation

    • Clogged gutters

    • Shrubbery or greenery that grows too close to your home

    Inspect these areas of your home looking for any signs of excess moisture, leaks, or water damage.

  2. Remove Infected Wood

    Use a chisel and wire brush to remove any areas of infected wood. Remember to wear protective gear, including a mask, goggles, and gloves while working.

    Keep chiseling and brushing until you've removed all the damaged wood and are left with a smooth surface.

  3. Add Wood Hardener

    You may not be able to remove all the damaged wood from the area. In that case, strengthen the wood by applying epoxy wood hardener to it. Use a foam brush to apply the wood hardener, allowing it to seep into the wood’s cracks and holes.

    Let the wood hardener dry for two to four hours.

  4. Patch the Wood

    Use a putty knife to smooth wood filler onto the rotted area. You want to create an even surface, but it doesn't have to be perfect.

    The wood filler should harden within an hour. Once it's hard to the touch, use sandpaper to smooth it down.

DIY vs. Hiring a Pro 

Left unchecked, dry rot can threaten your home's structural integrity. If you notice extensive sections, more than a few inches in size, of dry rot, you should call a water damage restoration company near you. In that scenario, replacing the damaged wood instead of repairing it is the best option.

A water damage pro can restore your home and give you tips and advice for making sure the dry rot doesn't come back.

Frequently Asked Questions

When you find water damage, your first order of business is to keep everyone on the property safe, so if you have standing water, evacuate if it’s safe. If possible, find the source of the water and stop it, which could mean shutting your water main to prevent pipe leaks. Next, you should notify your insurance company and immediately call a water damage restoration professional. They will work with you and your insurance company to create a solution to fix the issue and file an insurance claim for the cost of the damage.

The three methods or phases of water damage remediation are mitigation, remediation, and restoration. Mitigation is an emergency response that can include shutting off your water main or patching a hole in your roof from a fallen tree limb. Remediation includes drying the affected area, removing damaged materials, and dealing with any resulting mold growth. Restoration includes the build-back required to return your property to its previous condition. All three methods should be a part of any water damage remediation plan.

When hiring a water damage restoration company, you should confirm that the remediation plan includes fixing the underlying problem, dealing with resulting mold growth or rotted materials, and any making any build-back necessary to restore your property to its previous condition. Each phase of the remediation plan should include specific testing and inspection details to ensure the work is done properly and in a way that doesn’t prevent the restoration cost from being denied by your insurance provider.

If you find evidence of water damage in your home, your best option is to call a local water damage restoration company immediately. You could call a plumber first if you know that the issue is stemming from a plumbing pipe, but in many cases, a company that specifically handles water damage will be able to find the source of the damage and recommend a specific repair. Water damage restoration pros will also be able to develop a plan to remove any damaged material and restore your home to its previous condition.

The average water damage restoration cost is around $3,500, but it’s not uncommon to see prices fall between $450 and $15,000. Your project cost will depend on the extent of the damage, the source of the water, whether or not mold has grown in the affected area from the moisture, and the emergency level of your water problem. Keep in mind that your insurance company may cover some or all of your restoration expenses if your homeowner’s insurance policy covers the specific issue.

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