How to Patch Wood Siding

damaged wood siding

Wood siding looks great and lasts for a long time, but only if you give it the proper maintenance. Knowing how to patch wood siding is absolutely essential when you have wood siding because, sooner or later, these skills will be needed.

Having a professional come fix your wood siding can be a big expense, and it's an unnecessary one. Anyone can learn how to patch wood siding as a DIY project.

How to Patch Wood Siding

Making any sort of home repairs always feels like a pretty big undertaking. You have to have the tools and materials to make it happen, not to mention the skill and the time.

Patching holes, scratches, and nicks in wood siding doesn't take a professional touch, however. You can do this job fairly easily all on your own using stuff you can find at any hardware or home improvement store.

Wait until the meteorologists are predicting a few days of nice weather without much wind or rain, get the materials and tools you need beforehand, and you can often finish this DIY project in a long weekend.

Step 1 - Scrape

gloved hands scraping wood siding

Get a putty knife and scrape away any paint or debris. This requires a little bit of elbow grease, but it's worth it to get a clean surface to work with.

Scrape inside and all around the hole in a wide area. Later, you will be painting or staining this area, so keep this in mind while you’re cleaning the area.

Step 2 - Prep

What made the hole in your siding? Chances are, you will see rot or other damage around the area of the hole.

Using a flat-head screwdriver, preferably an old one you use for mean tasks like opening paint cans, dig out any rot or damaged wood from in and around the hole. Only clean, healthy wood should remain.

Do not worry if this causes you to make the hole deeper. You need a clean wood surface or your repair won't be nearly as effective.

Step 3 - Sand

Next, use sandpaper to smooth down the whole area. You want to sand the hole and the area around the hole until you have a smooth place to work.

Gently blow around and in the hole after you sand to get rid of any sawdust.

Step 4 - Apply Wood Filler

Wear gloves and safety glasses to apply wood filler, a paste- or putty-like substance. You can use a putty knife to apply the filler and smooth it into and around the hole, but if it's the putty knife you used earlier, be sure to clean it first.

Don't be sparing with your filler. Apply it liberally, packing it tightly into the hole and smoothing it all around the hole, too.

There is no "too much" wood filler. You will be sanding this all down later, anyway, so remember that sometimes more is more.

Step 5 - Wait and Grit

Allow the wood filler to dry completely according to the information on the label. This process could be as short as 30 minutes or take as long as several hours, depending on the product you're using.

Once the wood filler is dry, and only when it's dry, sand it all down again with sandpaper to make the area completely smooth. You want the surface of the patched area to be level and flat with the surrounding wood.

rotting wood damage in siding

How to Patch Bigger Holes

It's good when you can use wood filler to repair damage to siding, but sometimes, you may have more damage to your wood siding than that. In some cases, you will need to cut away old wood siding and replace part of the board completely.

Even this is not too big for a casual DIYer to tackle. However, you will need more tools, and you should work with lots of caution.

Step 1 - Remove

First, you need to cut away the damaged board to make your repair. Make cuts to both sides of the board where it needs to be moved, scoring it with a razor knife first and not cutting all the way through the board.

A circular saw with a wood blade can be used to cut into the board, but again, do not cut all the way through. When the wood is mostly cut, and after you remove the nails, the board should snap off when some pressure is applied.

Use a hammer to remove any nails holding the wood in place within the cut section. Then, use a pry bar to pull the board up and off the building.

Step 2 - Measure

Measure the space where you removed the piece of siding so you can cut a piece to size to make your repair. You need a very exact measurement, so take your time with this and get as precise as you can.

Step 3 - Cut

Cut a new piece of siding to match your measurements using a wood saw or a circular saw with a wood cutting blade. Always use caution with cutting tools and wear safety eyewear at all times.

Again, this needs to be very precise. Get as close to those measurements you took as you possibly can.

Step 4 - Nail

Place the new board flat, sliding it into place beneath the board above. Nail the board into place by driving nails through the top board, and then add more nails down the side and across the bottom.

Use stainless steel siding nails 3/4 inches long. Stainless steel is resistant to rust and is therefore waterproof—a must-have when it comes to exterior nails.

Step 5 - Caulk

Caulk the seams where the new board was installed and all the nail holes. You might need to apply caulk more than once when it dries and shrinks.

Use as much caulk as you need to completely fill seams and nail holes and sand it down smooth only once it's dry.

Finish the Repair

Once the hole is patched, whether you used filler or you replaced part of the board, you still need to finish your DIY home repair. Once all sanding is done, and everything is dried and cured, at least 24 hours after the repair work is done, you can prime and paint or stain.

Apply primer and paint or apply stain and polyurethane to the new area of the wood siding, matching it as closely as you can to the existing exterior.

How to Patch Wood Siding and Replace Damaged Boards

If you have wood siding, you need to know how to patch wood siding and, sometimes, how to replace damaged boards. Damage is going to happen no matter what, but good maintenance and quick repairs will keep the siding looking good.

As far as home repairs go, patching wood siding is affordable and fairly easy. If you work slowly and carefully, and precisely, just about anyone can complete this DIY task and repair their own wood siding.

Wood Siding FAQ

wood siding with fading paint

How much does it cost to patch wood siding?

Most of what you'll use to patch wood siding is highly affordable. Wood filler and sandpaper cost less than $15 each, on average.

Putty knives and screwdrivers are common household tools that most people have and cost around $10 each, on average, though they are available for much less.

Even if you're replacing a piece of the board itself, your biggest expense will be the piece of lumber you use to replace the board. A hammer and nails is a common combination that's highly affordable.

You can get a quality hammer for about $20 and nails for around $15.

If you need to replace a section of siding, you will need lumber. Depending on the type of lumber you buy, you will spend anywhere from $4 to $30 per square foot of wood.

Common wood types used for siding include cedar, pine, teak, and cypress.

In other words, it doesn't cost much to repair wood siding. Even if you're replacing a section of wood, you can probably get everything you need for this project for less than $50 to $100, depending on how big the repair is and how many holes in the siding you’re repairing.

How long does it take to patch wood siding?

It doesn't take a long time to patch wood siding if you don’t count all the dry time. Because you need to wait for things like wood filler, caulk, and paint to dry, the overall project could take you a few days to complete.

However, the actual work time you will spend on this project is rather small, compared to the total project time. You will spend a few hours, at most, of total labor on this entire repair.

When does wood siding need to be replaced instead of patched?

worker replacing wood exterior siding

Not all wood siding repair jobs are created equal. Where sometimes you can use wood filler, there are other times when the damage is so extensive you need to replace part of the board entirely.

If the damage on the board goes more than three-quarters of the way through the board or if the damaged area covers a large section of the board, you should replace the piece of board rather than attempting to patch it.

How long does wood siding last?

Wood siding is a reliable home building material that looks nice. With regular maintenance, such as repairing cracks and patching holes, wood siding will last from around 20 to 40 years.

In addition to making repairs, you need to reseal or repaint the wood siding every few years, at minimum every five years, in order to keep it looking good and help it to resist damage due to weather and wear and tear.

How does wood siding become damaged?

People have been building with wood for centuries, so why isn't it working for you? What kind of stuff might be causing damage to your home?

There are many reasons why it may be necessary to make repairs to your wood siding. Rotting, warping, mold, and cracks all result from weather conditions, such as ice and moisture.

Pests, such as woodpeckers and termites, cause damage to wood. Other animals can damage wood by attempting to nest in the wood.

No matter what is damaging your wood, you've got to repair it. If you think further action might be needed, such as finding termites in your wood, call a professional pest control company to find out what you need to do.

Plants can also damage your wood siding. Vining plants and clinging plants can wreak havoc on your exterior finish, damaging paint and the wood underneath.

Check regularly for plants all around the foundation and along the walls where wood siding is present. Pull up and cut away all plants growing near the siding.

Can this DIY project be completed alone?

In most cases, you can actually patch and repair your wood siding as a one-person DIY task. However, there are exceptions to this.

While you probably don’t need an extra body to help carry materials or perform heavy labor, there is one circumstance where you must have a helper: using ladders.

If the spot of wood siding you’re repairing is high up enough for you to use a ladder, you must absolutely have another person with you to do this project. Make sure another person is present every single time you are on the ladder.

This person should stand at the base of the ladder, holding the lading to keep it steady. This is a basic rule of safety you should follow at all times.

Otherwise, you can do this entire DIY project as a true do-it-by-yourself project. Remember to wear safety gloves and safety glasses and work carefully and slowly, which reduces the chance that you will make a mistake.

Further Reading

A Guide to Siding Types

All About Clapboard Siding

Cedar Siding Maintenance

Guide to Wood Siding

How to Restore Cedar Siding

To Paint or Not to Paint Your Siding