Siding
Cedar Siding in West Chester, OH: Repair, Rot, and Upkeep
Cedar siding lasts a long time when its finish stays sound and the wood can shed water and dry out. Upkeep comes down to four things: clean it, refinish it on time, keep it off the ground, and replace split or rotted boards before water reaches the wall. Peeling finish, black stains, and soft spots are the signs to act on.
Cedar shows up on many homes in West Chester and Northern Cincinnati, as full siding, shake gables, or accent walls. Our humid summers and freeze-thaw winters are hard on any wood. Early fall is a good time to check it, while the weather is still dry enough to refinish.
Why does cedar hold up, and where does it fail?
Western red cedar has a head start on most woods. The Western Red Cedar Lumber Association's quick facts sheet says its heartwood "has natural decay resistance" from natural compounds in the wood. It also says cedar has "a very low shrinkage factor" and resists warping, twisting, and checking better than other softwoods.
That does not make it rot-proof. The same sheet says that where cedar sits in conditions that favor decay, "such as where the wood is in contact with the ground," it should be treated with a wood preservative. Cedar siding most often fails in the places that stay wet:
- The bottom course, near soil, mulch, or a roof line
- Under windows and around doors, where water runs off
- Behind gutters and downspouts that overflow or leak
- Behind shrubs that keep the wall from drying
- Anywhere the finish has worn through to bare wood
How often should cedar siding be refinished?
It depends on the finish, the sun, and the weather each wall gets. The Real Cedar guide to choosing a finish describes the options:
| Finish | What it does | Upkeep |
|---|---|---|
| Paint or solid-color stain | Hides the grain. Shields wood from sunlight and water. | Longest between coats. Needs a stain-blocking primer. |
| Semi-transparent stain (oil-based) | Shows the grain, soaks in, does not form a film | Real Cedar says these can last 3 to 6 years before they need to be reapplied |
| Transparent stain | Shows the natural color, repels water | No UV protection, so it needs regular reapplication |
| No finish | Weathers to gray | The surface wears faster without protection |
Walls that face south and west take the most sun and usually need attention first. When the finish starts to fade, flake, or let water soak in instead of bead, it is time to recoat.
Prep matters more than the brand. Real Cedar recommends a stain-blocking primer under paint and solid stains. Cedar contains natural oils, called extractives, that can bleed through and stain latex paint.
What causes black stains and mildew on cedar?
Not every dark spot is rot. Here is how to tell the common ones apart, based on Real Cedar's care and maintenance guide:
| What you see | Likely cause | What to do |
|---|---|---|
| Black or blue-black streaks around nail heads | Iron in ordinary nails reacting with cedar | Clean with a commercial cleaner. Use only hot-dipped galvanized, aluminum, or stainless steel nails. |
| Dark spots that bleach out in under a minute | Mildew | Clean with a mild bleach solution or mildew remover, then refinish with a mildewcide coating |
| Reddish-brown runs or blotches | Extractive bleeding, caused by moisture | Find and stop the moisture source. Mild stains may wash away. |
| Gray, dull surface | Weathering from sun | Clean and refinish |
Real Cedar's guide says, "Restaining does not solve a mildew problem." Clean it off first, or it will grow right through the new finish.
How do you find rot in cedar siding?
Walk the house with a flat screwdriver. Press it into the boards at the trouble spots listed above. Sound cedar resists. Rotted wood feels soft or spongy, and the tip sinks in.
Also look for:
- Boards that are split, cupped, or pulling away from the wall
- Finish that keeps peeling in the same spot, which often means water from behind
- Water stains on interior walls under windows
If you find soft wood, find out how far it goes. Rot in one board's face is a repair. Rot that has reached the sheathing or framing is a bigger job.
How are damaged cedar boards repaired?
For split or rotted boards, replacing the board is the most reliable fix. Small soft spots can sometimes be cut out and filled, but a patch on wood that keeps getting wet will fail again.
A good cedar repair includes:
- Fix the water source first. A new board under a leaking gutter will rot like the old one.
- Check behind the board. Look at the house wrap and sheathing while the wall is open.
- Seal all sides. Real Cedar says to "apply products to all six sides of each board" and to touch up raw cut ends.
- Use the right nails. The Real Cedar pre-installation guide calls stainless steel nails "the best choice," with hot-dipped galvanized and aluminum as other corrosion-resistant options.
- Keep it off the ground. The same guide says to keep the lowest edge of siding at least 6 inches off the ground.
- Finish to match. New wood takes stain differently than weathered wood. Plan on refinishing the full wall if the color difference bothers you.
Is there lead paint on older cedar siding?
On a home built before 1978, painted siding may contain lead. The EPA's Renovation, Repair and Painting rule covers anyone paid to disturb paint in pre-1978 housing. The EPA's contractor page exempts small exterior jobs that disturb 20 square feet of paint or less. Scraping and sanding a whole house goes well past that. Ask any contractor about their lead-safe certification before work starts.
When does cedar siding need replacing?
Repair makes sense when rot is limited to a few boards and the rest of the siding is sound. Replacement is worth discussing when rot is spread across walls, the sheathing behind is damaged, or refinishing has become a cost you no longer want. Some owners replace cedar with new cedar. Others switch to a material that needs less upkeep. Our guide to fiber cement vs vinyl siding compares the two most common choices.
How Shamrock can help
We repair and replace wood siding, including cedar, along with vinyl, fiber cement, and aluminum. We will show you where the rot is, how far it goes, and whether a repair will hold. See our siding services or request a free estimate.
FAQ
Can I pressure wash cedar siding? I would not. Cedar is a soft wood, and high pressure can tear up the surface. Real Cedar recommends cleaning with a mild, non-phosphate detergent.
Should I let my cedar siding turn gray? You can, but bare wood takes on water and wears faster. If you like the gray look, Real Cedar notes that bleaching or weathering stains give that color sooner and more evenly.
Can I paint cedar that was stained before? Often, yes, with proper cleaning and a stain-blocking primer. Ask your paint supplier which primer works over your current finish.
What time of year is best for cedar repairs? Late spring through early fall, when the wood is dry and temperatures suit the finish. Check the finish label for temperature limits.