Sometimes you can see it, and sometimes you cannot. Sometimes you know it’s there, and sometimes you don’t. Sometimes the little soft spot turns out to be a big problem, and sometimes what you perceive to be a big problem is just a little one. This is the mysterious but destructive nature of dry rot.
What causes dry rot? Dry rot is caused when wood gets and stays wet frequently or for too long, and when airborne spores encounter that “ready to receive” wet wood. If wood has a moisture content over 20%, it is a prime target for those airborne spores. When the spores germinate in that moist wood, the breakdown begins. See this definition here by Allcottassociates.co.uk :
What is the Main Cause of Dry Rot?
Dry rot occurs when airborne spores come into contact with damp timber that has a moisture content of over 20%. These spores then germinate and sprout grey root hyphae strands. The hyphae grow into mycelium which covers the timber in a thick cotton-wool-like substance.
Dry Rot - Causes, Identification & Solution - Allcott Associates - allcottassociates.co.uk April 30, 2023
If you take a sharp “pokie-stick” like a screwdriver, an awl, or a long nail, you can poke at the affected area to see if you have a problem; if the pokie-stick goes easily into the wood, you have dry rot. Sometimes you can see it wrinkling on the edges of rafter tails, or at the bottom of wood that is close to the ground. Sometimes you can see it on exposed beams or wood that sticks out and is wet frequently. Sometimes the sprinklers hit the wood siding on your house and cause damage.
Whichever way your home is being exposed to moisture or the weather, one thing is certain: if dry rot gets established and is left unattended it can spread to other areas and even affect an entire building. The best idea is to get in touch with a trusted general contractor and have him or her come out and do an assessment of your home. Sometimes it’s a little fix, and sometimes it’s a big one.
The image below was the inside of a structural column supporting the entire front porch entry of a single-story home located in Greenhaven. The only clue that there was rot inside was some soft spots on the trim and siding that wrapped this column. Once exposed, it was clear that the whole column needed to be rebuilt. There remains no structural integrity to wood that has succumbed to dry rot.
Dry Rot Can be Caused by Bad Design
A very frequent cause of dry rot is water that drips from overflowing gutters, or water that comes down fascia boards on gables and siding. Some buildings just have a bad design—by a bad design, I mean that the building may look great when newly built, but wood that is decorative only and exposed to the elements over time is prone to decay; wood that is structurally necessary is also prone to exposure and decay—but adding a wood feature to the home just for looks and that is exposed to the elements adds unnecessary costs and risk, and is considered bad design.
One bad design we see all the time is extended and exposed beams. This style of home can be seen in the Greenhaven area, and in some areas of Land Park in Sacramento. Exposed beams are aesthetically pleasing and very functional as they straddle the top plates of the wall assemblies and support the roof, but when they extend out past the roof and fascia and are susceptible to the elements, over time they invariably fail and get dry rot. Here is a picture of a beam and fascia board that was literally crumbling to the touch—this beam runs all the way through the house and sits on the top plates of the wall system, which is holding up the roof. Had this rot gotten past the exterior wall of the house, the repair would have been substantially more difficult and more costly. We ended up having to cut back the whole front roof line by about a foot or foot and a half just to get past the dry rot to reach good, solid wood.
Do I Need a Permit to Fix Dry Rot?
If you are a homeowner that is somewhat handy you can do some of these repairs yourself. The “trigger” for a permit is if you are replacing something structural (holds the building or part of the building up) or if you are replacing something that has a water barrier, the siding for example. The City and County building departments are there for your protection—inspectors will come out to make sure you are doing it right and up to current building codes. If you are planning to do the repairs yourself, you can contact the building department and ask if you need a permit, and if you do, you can get your own permit as an “Owner—builder.” An owner-builder can do the work on his or her own property but is not allowed to hire any helpers, that’s where worker’s compensation comes into play.
Many people opt to hire a licensed contractor to complete the work. For example, if you know that you need a siding contractor and happen to know a siding contractor, you can hire them to do your project. Most people seek out and utilize a general contractor. A trusted general contractor can do any project on your home, so if a wall gets opened and structural work needs to be done, or plumbing work needs to be done, or electrical work needs to be done, or drywall work needs to be done, the general contractor has both the license, resources, and experience to do it. General contractors are familiar with the permitting process and can navigate the City or County building department whose jurisdiction you live in.
If you suspect that you have dry rot in your home and aren't a DIYer, call us today at (916) 838-7578 or click here to fill out a form. We'd be happy to help you out.