Why Dry Rot Is a Risk For Southern California Homeowners & What To Do About It

Dry Rot in Southern California

Two of the issues Southern California homeowners fear on their inspection reports are dry rot and termites, because it means fairly immediate repairs are necessary of damage that isn’t always visible to the eye.

The fact is that both issues are common near the coast, so it’s important to keep an eye out for signs of damage and contact a professional immediately if you suspect either might be present in your home.

What is Dry Rot?

Dry rot is actually a fungus called Serpula lacrymans that can destroy both hard and soft woods by  removing moisture (hence the name) as it travels by, basically, eating the wood and carrying the water away.

Dry rot begins when moisture gets trapped on wood where it can’t dry out and because it travels on the inside of wood, it can even affect wood that appears dry on the surface.

Damp Southern California coastal fog and ocean air contribute to dry rot problems near the coast in San Diego and Orange County, therefore, it’s especially important to stay on top of leaks and maintain exterior weather proofing to prevent it.

The reason why dry rot needs to be identified and removed quickly is that it can spread even through masonry (though it does not impact masonry) and other building materials into hard-to-reach areas.

How to Identify Dry Rot

Look for discoloration in the wood (typically a darker brown), cracks in a cuboidal (looks like square or rectangular cracks) shape, red dust surrounding the area as well as a musty, mold-like odor.

Because the fungus strips the wood of moisture, it shrinks, while sometimes a white cotton ball-like fuzz is seen on the wood.

In humid conditions, visible signs of a mushy fungus or mycelium that’s orange in color can become visible.

However, painted surfaces can hide dry rot so look for spots where the wood looks sunken in or shriveled behind the paint.

Use a metal ice pick or small screw driver to penetrate the wood and if the prong can pierce the wood easily or if the wood feels softer than normal, dry rot might be present.

Areas Prone to Dry Rot

Because water tends to pool and sit on top of decking, it’s extremely prone to dry rot which why use of rot-proof wood like cedar or pressure treated wood in decking applications is essential to avoid jeopardizing structural integrity.

Lattices, especially those covered in plant material, as well as trellises and fencing are all prone to dry rot if not sealed or maintained properly.

It is especially important that stucco be prevented from wicking moisture up from wet soil, which can be a risk with older homes near the beach before use of weep screeds. Weep screeds are installed at the bottom of a stuccoed wall and allow moisture to drain out of the stuccoed wall as well as prevent moisture from entering the stucco from the ground and damaging wood framing.

In coastal areas, another place where dry rot is commonly found is around leaking windows or doors that we improperly installed without enough waterproof flashing material.

Dry rot is also found in bathrooms due to pipe leaks and increased humidity from showers and baths, but again it’s not as present inland where the air is hotter and drier.

How to Repair Dry Rot

If dry rot is caught early, the affected wood can be simply cut out and replaced or sealed with a filler that reinforces damaged wood fibers.

Sometimes boric acid or borate is used as a fungicide on larger attacks to treat and prevent further attacks, but it’s important to leave a big job to a professional.

If it’s a small infection on a non-weight bearing surface, all that may need to be done is a sanding and application of an epoxy-like wood hardener.

The trick is that it’s critical for every single remnant of dry rot to be eliminated so you’ll need a trained eye and perhaps some testing kits to avoid missing any, which would void any repair efforts.

Remember, dry rot can spread like a cancer.

We found dry rot during our remodel in studs supporting our house and our contractor simply cut out the damaged wood and replaced it with a brand new, pressure treated stud.

What Happens if Dry Rot is Left Unattended?

What Happens if Dry Rot is Left Unattended


Dry rot will ruin the structural integrity of your home, deck or decorative structure if not treated properly which is why it’s often likened to a cancer.

Because it’s relatively common in Southern California, a variety of companies specialize in spotting and removing dry rot.

Dry rot also attracts wood eating insects like termites, which is why you often see evidence of both simultaneously.

How to Identify Termites

Subterranean termites and dry rot both typically enter the home via wet soil, however, there are a handful of differences to determine whether you have one or the other (or both).

Subterranean termites are small insects that live in colonies under the soil, usually, and dine on cellulose in wood which means that they hollow it out leaving weak or brittle wood.

Like dry rot, these pests create tunnels except that they are in more of a branch form versus cuboidal and they like to crawl into the home via cracks in the foundation, too.

The tunnels are smooth and sort of looks like a worm may have burrowed through.

With the help of a professional, insecticides or termiticides can treat subterranean termite infestations and, of course, the larger dry wood termites that are a little bit easier to spot.

Your Turn…

To be completely honest, whether you have termites or dry rot in your Southern California home, it’s best to consult a professional rather than attempt to tackle it on your own as they can identify the tunnels created by both fungi and insects, remove the proper amount of damaged wood and repair the wood in a manner that also protects against future damage.

A variety of contractors can help identify and remove dry rot including your local handyman, painter or pest control company so be sure to call around for details.

Have you experienced dry rot in your home? Tell us about your story and/or any tips you may have in the comments below…

Photo credit: top photo, Wikimedia Commons/Mätes II (own work); bottom photo, Flickr/Brownkittenstew (aka BKS)