wood rot repair

Wood Rot Repair: A DIY Guide For Homeowners

Having rotted wood in your home, especially in crucial areas like windows, walls, and door frames, can be both frustrating and dangerous. Whether it’s in window sills, floor beams, or other parts of your home, rotten wood can compromise the structural integrity and become a safety issue. This guide, perfect for those interested in home improvement, is designed to homeowners how to spot, prevent, and fix rotted wood.

Can rotted or damaged wood be repaired?

A example of dry rot in a bathroom
Dry rot wood in a bathroom

Yes! Rotten wood can be repaired. Start by removing the rotting parts from the original board or joists. Then, fill the surrounding wood area with a soft wood polyester filler or wood putty using a plastic putty knife. This material fills the void and cures to ensure strength and resilience.

It’s essential to determine when rotten wood should be replaced or repaired. If the wood is too rotten, the repair might not be effective. In such cases, replacement is recommended, and you may consider a carpentry company if it’s a complex project. However, there are ample opportunities to repair rotten wood that isn’t too far gone.

How to determine if rotten wood needs to be repaired or replaced?

A reliable way to determine the condition of a piece of wood is by checking for:

  • Deep cracks across the grain
  • Off-white fibers of the fungus
  • Growth of mushroom-like substances on the surface
  • Off-white or yellow tinge on the brickwork

If these signs are prevalent, it’s often better to replace the wood. However, if only certain sections are affected, and the rest remain sturdy, a repair might suffice.

To test the wood’s condition, use a knife or screwdriver. If it feels spongy and sinks in more than 1/8″, the wood likely needs replacement. Recognizing the difference between repairable and irreparable wood is crucial for maintaining the safety and aesthetics of your home.

Types of Rotting Wood – Dry Wood Rot and Termite damage

Both wood rot and termite damage can compromise your home’s structural integrity. It’s essential to differentiate between the two to address the issue effectively.

Dry rot, caused by fungi, can lead to significant structural damage. Recognizing dry rot is the first step toward remediation. Infected wood might feel damp and soft, and probing the damaged areas with a screwdriver could reveal a mushy texture. Other signs include deep cracks and visible fungal growth around the affected area. If left untreated, the wood becomes brittle and crumbles under pressure.

A rotted wooden board from termite damageGetting Rid of Dry Rot

If dry rot has extensively damaged your wood, replacement is the best course of action. However, if only small sections are affected, you can salvage the wood. Since dry rot is a fungus, it’s vital to eliminate it to preserve the surrounding wood.

Start by removing the infected portions, and scraping away any weakened sections. Then, adopt a suitable method to eradicate the dry rot and prevent its recurrence.


How to prevent dry rot

Protecting your home’s wooden structures from dry rot is paramount. Here are some steps you can take:

  • Eliminate excess moisture, as rot fungi thrive in damp conditions.
  • Treat joists with fungicides when undertaking repairs to prevent future infestations.
  • Regularly inspect your home for leaks, ensuring that gutters are clean and water is effectively drained away.
  • Add caulk or sealant around areas prone to moisture, like panels, windows, and door frames.
  • Apply a polyurethane coating to the wood to shield it from water damage.

These precautions can save you the hassle of dry rot.

How to repair rotted wood

caulking around a wooden door frame to prevent wood rotWhat you need to repair rotten wood

Before diving into the repair process, ensure you have the right tools:

  • Knife or chisel
  • Wood filler like Bondo or epoxy resin
  • Spatula or Putty Knife
  • Wood grinder or sander
  • Wood primer
  • Paint

These tools are essential for the effective repair of rotten wood.

Which wood filler to use?

There’s a variety of wood filler products available, both offline and online. Softwood polyester fillers or epoxies are popular choices due to their durability and compatibility with wood. For those deeply involved in woodworking, it’s beneficial to keep a wood putty or filler on hand, especially if your home features extensive wooden elements like porches or sidings.

5 Ways to Repair Rotted Wood Without Replacing It

Wood is susceptible to rot when exposed to moisture. However, with the right techniques, you can restore its former glory. Here are five methods to repair rotted wood:

Method 1 – Remove the rotten part of the wood

Rotted wood that needs to be removedStep 1 – Scratch the rotten wood and dig up loose rot using a claw hammer. Place the hammer claws at the root of the rot. Apply pressure when pulling the nail back toward you. Remove as much rotten wood as possible without damaging the good wood. Focus on removing only the soft and rotten wood.

Step 2 – Remove the remaining rotten wood using a router with a V-shaped bit. Hold it while keeping the drill bit 3.2 mm or 1⁄8 inch from the wood’s back edge. Use short back-and-forth movements to remove rot that the hammer did not reach. Continue grinding the wood until you reach healthy, solid wood. If any rotting is left behind, it could cause further damage. Note: Hardwood can be more challenging for routers to cut.

Step 3 – Remove the paint and surface rot since many touch-up solutions don’t adhere to existing paint. Use a paint scraper or coarse 60-grit sandpaper to remove any residue, dirt, rust, or primer on the wood surface. Apply consistent pressure when working in a circular motion.

Step 4 – Apply 4-6 coats of a wood repair agent to the area. Use the included brush to paint the entire surface of the restorer. Work the restoration between layers for 2 minutes to ensure it penetrates the wood. Allow the repair agent to dry completely for 2 hours before reapplying. When using the repair agent, wear rubber gloves to avoid skin contact.

epoxy wood repairMethod 2 – How to fix the area with Epoxy

Step 1 – Prime the wood with a binder or binding agent.

Step 2 – Mix the two-part epoxy consolidant with a putty knife on a non-porous surface.

Step 3 – Use the putty knife to mold the epoxy filler into the wood.

Step 4 – Scrape off excess epoxy filler with a clean putty knife.

Step 5 – Allow the epoxy filler to set overnight.

Method 3 – Creating a Wood Patch

cutting a wood patch to repair rotten woodStep 1 – Use a Japanese hand saw to cut the wood smoothly and straight.

Step 2 – Cut a piece of cedar to fit the size of the hole you’re filling.

Step 3 – Dampen the exposed wood with a cloth.

Step 4 – Apply polyurethane glue to the wood and position the patch.

Step 5 – Drill two screws on each side of the patch to secure it in place.

Step 6 – Remove excess glue from the patch after 6 hours.

Method 4 – Use a wood filler to fix and patch

applying a wood filler to fix rotten woodStep 1 – Pour a 3-inch diameter of wood filler onto a non-porous surface.

Step 2 – Push the filler wood hardener tube with the cap on.

Step 3 – Place a 3-inch strip of hardener on the putty and mix with wood hardener.

Step 4 – Apply the filler with a putty knife, applying firm pressure to the wood.

Step 5 – Allow the filler to dry for 30 minutes.


Method 5 – Wood repaired with sand, patch, and varnish

sanding down a rotted piece of wood to repair itStep 1 – Smooth the patch with sandpaper.

Step 2 – If the original wood is discolored, use the appropriate stain.

Step 3 – Once the wood is stained, apply primer at least twice.

Step 4 – Once the primer is dry, apply the paint.

How to Care for Wood

Proper care of wooden furniture in the home can prevent wood rot. Sealing wooden fixtures with wood stains, paint, or a clear sealer can protect them from fungus, water damage, termites, and other potential harm.

Here’s what you can do:

  • Use a paintbrush to repaint or touch up your house every 5 years to protect the wood.
  • Annually clean your wood fixtures and accessories, removing mildew that could lead to mold.
  • Clean wood using warm soapy water and a scrubbing brush to remove dirt and other debris.

The methods mentioned above are safe for rotten wood repair in your home. Whether it’s about wood repair or replacement, always take precautions and necessary steps to ensure your home remains safe for its inhabitants. Proper care and maintenance are integral parts of homeownership.

About Peter Jacobs

Peter Jacobs is the Senior Director of Marketing at CNC Masters, a leading supplier of CNC mills, milling machines, and CNC lathes. He is actively involved in manufacturing processes and regularly contributes his insights for various blogs in CNC machining, 3D printing, rapid tooling, injection molding, metal casting, and manufacturing in general. You can connect with him on his LinkedIn.

Have Questions? Need a Quote?

Looking for more information about our CNC machines and services? Contact us today.


Slide 1

29. Create a Peck Drilling Program in Circular or Rectangular Patterns
Using the Circular or Rectangular Drilling Wizards, you can program the machine to drill an un-limited series of holes along the X and Y planes. Program it to drill straight through to your total depth, use a high-speed pecking cycle, or deep hole pecking cycle. You can program the cut-in depth and return point for a controlled peck drill application to maximize chip clearance.

Slide 1

20. Change up to 30 tools with compensation, and store your tool offsets for other programs
The MX supports…

Slide 1

21. Use the optional ATC rack up to 8 tools for milling, drilling, and rigid tapping applications
The CNC Masters Automatic Tool Changer Rack and Tools (US Patent 9,827,640B2) can be added to any CNC Masters Milling Machine built with the rigid tapping encoder option. The tutorial will guide you through the set-up procedure using the ATC tools.

Slide 1

22. Use the optional Rigid Tapping Wizard without the need for tapping head attachments
When you order your CNC Masters machine, have it built with the optional rigid tapping encoder. You can take any drill cycle program and replace the top line with a tapping code created by the wizard to tap your series of holes up to 1/2” in diameter.

Slide 1

23. Use the optional Digital Probe to scan the profile and/or pockets of your fun/hobby type designs to write your tool path program and machine out a duplicate of your original design To “surface” scan an object, you can program the probe along the X or Y plane. The stylus will travel over the part starting on the left side front corner of the object and work its way to the end of the part on the right side. Depending on how the stylus moves, it will record linear and interpolated movements along the X, Y, and Z planes directly on the MX Editor.
To “pocket” scan an object containing a closed pocket such as circles or squares, the scan will start from the top front, work its way inside of the pocket, and scan the entire perimeter of the pocket.
Under the Setup of the MX software you will find the Probe Tab which will allow you to calibrate and program your probe. Your “Probe Step”, “Feed”, and “Data Filter” can also be changed on the fly while the probe is in the middle of scanning your object.

Slide 1

24. Use work offsets G54-G59 for nesting applications
The work offsets offer you a way to program up to six different machining locations. It’s like having multiple 0.0 locations for different parts. This is very useful especially when using sub-routines/nesting applications.

Slide 1

25. Create a Rectangular Pocket / Slot with our selection of Wizards to help you build a tool path program
The Cycle Wizards for the mill or lathe makes it easy to create a simple tool path without needing to use a CAD and CAM software.
On this Wizard, the Rectangular Pocket / Slots, can be used to form a deep rectangular pocket into your material or machine a slot duplicating as many passes needed to its total depth.

Slide 1

26. Create a Circular Pocket Wizard
Input the total diameter, the step down, and total depth and the code will be generated.

Slide 1

27. Do Thread Milling using a single point cutter Wizard

Slide 1

28. Cut a gear out using the Cut Gear Wizard with the optional Fourth Axis

Slide 1

19. Disable the axis motors to manually hand crank each axis into place
Easily de-energize the axis motors by clicking [Disable Motors] to crank each axis by hand, and then press [Reset Control] to re-energize the axis motors.

Slide 1

30. The MX interface can easily be interchanged from Mill Mode to Lathe Mode
Use this interface for your CNC Masters Lathe. It contains all the same user-friendly features and functions that comes in Mill Mode. Simply go to the Setup page and change the interface.

Slide 1

31. Use Tool Change Compensation or the optional Auto Tool Changer Turret if your application requires more than one tool in a single program
You can offset the length and angle of each tool and record it under Tools in your Setup. The program will automatically pause the lathe’s movement and spindle allowing you to change out your tool, or allowing the optional ATC Turret to quickly turn to its next tool and continue machining.
On the MX interface, you also have four Tool Position buttons. Select your desired T position, and the auto tool post will quickly turn and lock itself to that position.

Slide 1

32. Use the Lathe Wizard Threading Cycle to help you program your lathe’s internal or external threads in inches or metric

Slide 1

33. Use the Lathe Wizard Turning / Boring Cycle to help you program simple turning and boring cycles without having to go through a CAM or writing a long program with multiple passes

Slide 1

34. Use the Lathe Wizard Peck Drilling Cycle to help you program your drill applications or for face grooving

Slide 1

35. Facing / Grooving / Part Off Cycle Wizards – with Constant Surface Speed
These cycles can be used with Constant Surface Speed allowing the spindle speed to increase automatically as the diameter of the part decreases giving your application a consistent workpiece finish. With CSS built into the wizard, there is no need to break down the cycle into multiple paths and multiple spindle speed changes.

Slide 1

36. This is our list of supported G and M codes which can be found under Tools > G Code/ M Code List in the MX
If you plan to use a third-party CAM software to generate your tool path program, use a generic FANUC post processor and edit it to match our list of codes. As an option, we also sell Visual mill/turn CAM software which comes with a guaranteed post processor for our machines to easily generate your tool path programs based on your CAD drawings.

Slide 1

37. Our pledge to you…

Slide 1

10. Run each tool path independently to study its movement
1. Run the machine on Trace mode. You can run each tool path independently, one line at a time to study the tool path movement on the machine to verify the position of the application and if any fixture/vise is in the way of the cutter’s path.

2. You can also verify your program by clicking on the Trace and Draw buttons together. This will allow you to view each tool path independently one line at a time in the Draw Window.

Slide 1

2. Clutter Free Interface
The MX is engineered for the CNC MASTERS machine so you do not have to fiddle with a detailed complicated configuration that can be overwhelming. Just load in the MX and start machining!2. Clutter Free Interface
The MX is engineered for the CNC MASTERS machine so you do not have to fiddle with a detailed complicated configuration that can be overwhelming. Just load in the MX and start machining!

Slide 1

3. Features Tour and Tutorials Included
The Features Tour will give you a quick run-down on all the features the MX can do for you. The Tutorials are easy to follow even for the first time CNC machinist.
Feel free to download the MX on any of your computers. We recommend downloading the MX along with your CAD and CAM software there at the comfort of your office computer to generate your tool path programs. You don’t need to be hooked up to the machine either to test your program in simulation mode.

Slide 1

4. Navigate and Edit Your Program through the MX interface with Ease
With a few clicks of the mouse or using touch screen technology, you can easily navigate through the MX interface importing saved programs into the Editor from the File drop down menu. Using standard windows features to edit your program you can then lock the Editor Screen to avoid accidental editing, and if you need to insert a line in the middle of a program, just click on [ReNum] to re-number your tool path list.
You can create a program or import CAM generated G-code tool paths into the Editor
The X Y and Z W arrow jog buttons are displayed from the point of view of the cutter to avoid confusion when the table and saddle are moving. You can also adjust your spindle speed and coolant control while jogging each axis.

Slide 1

5. Feed Hold – Pause in the Middle of your Program
Feed Hold lets you pause in the middle of a program. From there you can step through your program one line at time while opting to shut the spindle off and then resume your program.
You can also write PAUSE in the middle of your program and jog each axis independently while your program is in pause mode.

Slide 1

6. Hot Keys
Hot Keys is an alternative method to easily control your machine using your hard or touch screen keyboard. One can press P to pause a program, press S to turn Spindle On, G to run a program, Space Bar to Stop, J to record your individual movements one line at a time to create a program in teach mode.

Slide 1

7. Pick Menu – for conversational mode programming
Write FANUC style G-codes directly into the Editor or select commands off the [Pick] menu and write your tool path program in conversational mode such as what is written in the Editor box. You can even mix between conversation commands and G-codes in the same program.

Slide 1

8. Pick Menu List of Options
Use commands such as MOVE, SPINDLE ON/OFF, COOLANT ON/OFF, PAUSE, DELAY, GO HOME…. to write your tool path programs in conversational mode.

Slide 1

9. Draw the Tool Path to verify it before pressing Go
Hit Draw to view your tool path program drawing, check out its run time, or even simulate the tool path in 3D mode. This can be helpful to quickly verify your program before running it. You can also slow down or speed up the drawing or simulation process.
You can also hit Go within the Draw Window itself to verify the cutter’s position on the machine. The current tool path will be highlighted and simultaneously draw out the next path so you can verify what the cutter will be doing next on the program.

Slide 1

MX Software – Easy to Use, Easy to Learn – Included with your machine purchase
The MX software is designed to work seamlessly with your CNC Masters machine. It is made to work with Windows PC – desktop, laptop, or an all in one – on standard USB. Use it on Windows 8 or 10 64-bit operating systems.
No internal conversion printer/serial port to USB software or additional conversion hardware is used with the MX.

Slide 1

11. Counters display in Inches or Millimeters – Continuous Feed
1. When running a program, the counters will display a “real-time” readout while the machine is in CNC operation without counting ahead of the movement.
2. The current tool path is highlighted while the machine is in operation without causing slight interruptions/pauses as the software feeds the tool path to the machine. The MX internally interprets a program ten lines ahead to allow for “continuous machining” avoiding slight interruptions as the machine waits for its next tool path command.
3. “Run Time” tells you how long it takes to run your tool path program.

Slide 1

12. Use the “Go From Line” command to start in the middle of your program
If you ever need to begin your program from somewhere in the middle of it, use [Go From Line] which you can find under Tools. The Help guide will walk you through how to position the cutter without losing its position on the machine.

Slide 1

13. Exact Motion Distance without over-stepping on an axis while jogging
Use “Relative ON” to enter a specific coordinate to jog any of your axes to an exact location without having to write a program. It’s like using “power feed” but easier. You can jog an exact distance on any of the axes without needing to keep the key pressed down and mistakenly over-step the movement releasing your finger too slowly off the jog button.
Let’s say you need to drill a hole exactly 0.525” using the Z. So you enter 0.525 in the Z box. Next, adjust the JOG FEED RATE slider for the desired feed rate. Then “click once” on the +Z or -Z button to activate the travel. In this case you click once the -Z button first to drill the hole exactly 0.525”. Then click once on the +Z button to drive the axis back up 0.525”.

Slide 1

14. Teach Mode – Jog Input
You can create a tool path program by storing each point-to-point movement by simply jogging an axis one at a time. Click on either of the Jog Input buttons to store each movement on the Editor Screen. You can then add Spindle ON, feed commands, and press GO to run the new program as needed. This is a great feature to help you learn to create a program by the movements you make on the machine without necessarily writing out an entire program first.

Slide 1

15. Override on the fly to adjust the Jog Feed to Rapid or the Spindle Speed during the middle of a program
1. Jog Feed and Rapid with Override: You can adjust feeds using the slider from slow minimum 0.1″ per minute to a rapid of 100″ per minute of travel. You can even micro-step your jog as low as 0.01”/min. The [-][+] buttons allow you to fine tune feeds in 5% increments while the program is in motion.
2. Spindle Speed with Override: You can adjust speeds using the slider from a slow minimum RPM to the max RPM according to the machine setup. The [-][+] buttons allow you to fine tune feeds in 5% increments while the program is in motion.

Slide 1

16. Adjust Counters using Pre-Set if you cannot begin the program from 0.00
In a situation where you cannot begin your cutter at it’s 0.00 location, you can “Pre-Set” directly into the counters by typing in your beginning coordinate. You can press Go from here to run your program. You can also “zero all” or “zero” your counters independently. With one click of the [Return to 0.0] button, all axes will travel back to its respective 0.0 on the machine.

Slide 1

17. Set and Save your 0.00 position for future runs
Set and save your 0.00 position on the machine. These coordinates will be recorded as the first line of the program in the Editor Screen. Should you desire to return to this program at a later date, you only have to click on the Set Zero Return button. This will command the machine to automatically jog each axis to its saved “set” 0.00 position according to the recorded coordinates at the first line of the program.

Slide 1

18. Create a “Home” position to clear your application and run multiple times
Let’s say you need to machine one application times 100 pieces. This usually requires a jig to retain that physical 0.00 position. But in this case, you want the program to end with a clearance of the axes to easily switch out the next piece of stock and start again. With Save Home, you have the ability to save this offset (home) position while still retaining your Set Zero position where the machine will mill your part out. Pressing [Save Home] will record this new position under the Set Zero line in your program.
Pressing [Go Home] will jog your axes back to your “saved home” position where you originally pressed the Save Home command. You can also input GO_HOME from the Pick Menu as its own tool path in your program. At the completion of your program the axes will end at your Home position. Replace your part, then press [Return to 0.0] button to allow the axes to return to its zero position, and press Go to start your next run.

previous arrow
next arrow