How to Seal a Wood Fence

Re-sealing is an essential part of wood fence maintenance. It prevents rain and UV rays from saturating and weathering wood before its time, ensuring your wood fence lasts longer. Not to mention, it’s one of the most cost-effective ways to instantly improve the visual appeal of your property. 

Today, we’re teaching every homeowner the basics of how to seal a wood fence. You’ll learn the process, the importance of preparation, and common mistakes to avoid. 

How often should you seal a wood fence? 

Wood fences need sealing every one to three years, but this can vary depending on their age, current condition, and amount of sun and moisture exposure.  

Materials and supplies for sealing a wood fence 

Depending on the condition of your fence and your chosen application method, here’s a list of materials and supplies you might need to seal a wood fence. 

Repair and preparation supplies 

• Hand tools for repair (hammer, level, drill, tape measure) 

• Landscaping equipment (lawnmower, pruning shears, trimmer) 

• Sanding equipment  

Cleaning supplies 

• Diluted soap 

• Bleach solution for mildew 

• Scrub brush 

• Pressure washer or hose 

• Wood conditioner (optional) 

Application equipment and supplies 

• The correct quantity of UV and moisture-resistant wood sealant 

• Ladder (for taller fences) 

• Gloves 

• Application equipment (brushes, rollers, pans, sprayer) 

• Masking tape (for hardware) 

• Mask/safety goggles 

How to seal a wood fence step by step 

Learning how to seal a wood fence yourself is fairly simple and can be completed in three stages. Here’s how: 

1. Inspect the fence and perform any necessary repairs. 

Repair or replace any damaged boards or panels and tighten the hardware. Some fences may need light sanding to remove splinters and layers of previous sealant.  

If you have a painted fence or are considering painting, touchups and new paint jobs come before sealing. Check out some of these fence painting ideas for more tips and inspiration.  

PRO TIP: Trim away vegetation to prevent plant matter from getting glued to the fence with sealant. 

2. Clean the fence and allow it to dry completely. 

A bristle brush can remove debris, while a pressure washer can dislodge algae, mildew, and dirt. Newer fences may only need some gentle soap and a hose.  

After washing, let the fence dry thoroughly. It may take up to 48 hours for a fence to air dry, but it’s important that no moisture remains when applying sealant. 

Optional: Consider adding a wood conditioner to weathered, dry fences after cleaning.  

3. Applying the sealant. 

Choose a sealant that offers protection from both UV rays and moisture. Apply a thin layer with a brush, roller, or sprayer and allow to dry before applying a second coat. 

This is general advice. Always read the sealant manufacturer’s instructions and warnings before application. 

PRO TIP: Working from top to bottom can prevent drips. 

Common mistakes to avoid when sealing and staining wood fences  

If this is your first time sealing your wood fence, watch out for these mistakes. 

Rushing through the preparation stage 

Like most tasks, the time spent preparing is the biggest factor in a job well done.   

If the old sealant hasn’t worn away, sand as much off as possible. Anything from 80-120 grit sandpaper may be appropriate, but it depends on the type of wood and the current condition of the fence. Newer fences probably don’t need any sanding.  

Clean the fence as thoroughly as possible and make sure tall grass, shrubs, and overgrowth aren’t encroaching on the fence line.  

Remember that any mildew, dirt, marks, or debris will be trapped under the sealant if you don’t remove it first.  

PRO TIP: Check the weather forecast in the days surrounding resealing. Ensure enough time for the fence to dry both after washing and after applying the sealant. Extremely hot temperatures can cause bubbling or patchiness. Sealing wet fencing can trap moisture that leads to rot. 

Not taking the time to choose the right sealant 

Always choose sealants that provide UV and moisture protection. But more importantly, patch test. You want to know how the new layer will alter the appearance of a fence that is already painted or stained.  

The same applies if your fence is bare pressure-treated pine or something similar. Pressure treating can give wood a vaguely greenish hue. Applying a bit of the sealant or stain in an inconspicuous area is the only way to know exactly how it will turn out, even if it’s a clear coat. 

Applying thick layers of sealant 

Laying sealant on thick will not offer better protection. On the contrary, it will lead to uneven coverage, bubbling, drips, or peeling. Very thick layers of sealant will never fully dry, leaving a wood fence sticky.  

Thin, even coats are the way to go. Remember to read the instructions and recommendations on the sealant’s packaging.  

Is it time to replace your wood fence?  

Sealing a wood fence can increase the lifespan of your fence. However, if you’re dealing with persistent rot, sagging panels, damaged posts, or numerous broken boards, replacing the fence may be more cost-effective.  

Get the best mix of privacy, security, and curb appeal with Top Rail. We offer fencing solutions for all goals and budgets, so request your free estimate today. 

FAQ about sealing wood fences 

Is it worth sealing an old fence? 

Yes, if the fence is structurally sound, it is worth sealing it. It will improve its appearance and prevent further weathering until it’s time to replace it.  

What is the easiest way to seal a fence? 

The easiest way to seal a fence is with a sprayer. Sprayers apply sealant the fastest and make it easier to get thin, even coats. They’re also best for large fences, where it’s difficult for one or two people to complete the job by hand in a day.  

Does a pressure-treated wood fence still need to be sealed? 

Yes. Sealant maximizes the durability pressure-treating adds to wood. However, it may be best to wait a few months to a year before applying stain or sealant to new fences made of bare pressure-treated wood.  

Some types of pressure treatment involve preservatives that can eventually leach out of the wood. Sealant can help mitigate this.