Gravel Boards Explained: Types, Sizes and Installation Guide

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Gravel boards are used at the base of a fence to help protect panels or fencing boards from ground contact, moisture and general wear. Choosing the right gravel boards can improve the appearance, stability and lifespan of a fencing project.

What is a gravel board?

A gravel board is a long length fitted along the bottom of a fence, between the fence panel or fencing boards and the ground. It creates a barrier that helps keep timber away from damp soil and standing water. These gravel boards are commonly made from concrete, timber or composite plastic.

Without a gravel board, fence panels or feather edge boards can sit close to the ground. Over time, this can increase the risk of rot, movement and early damage, especially where soil builds up at the base of the fence. 

Gravel boards can also create a neater finish, particularly where ground levels vary along the fence line. 

What are gravel boards used for?

Gravel boards are mainly used to protect fencing and improve the finished look of a fence line. They can be useful on both residential and commercial fencing projects, especially where durability and maintenance are important. 

Common uses include:

• Raising timber fence panels away from the ground 

• Protecting feather edge boards from soil contact 

• Creating a level base line 

• Reducing moisture exposure at the base of the fence 

• Helping with slight changes in ground level

• Protect against rot and damage from insects

They can also make future repairs easier. If the base of the fence is exposed to wear, the gravel board can often be replaced without needing to replace the whole fence panel. 

Types of gravel boards

The two main types of gravel boards are concrete gravel boards and timber gravel boards. Both can work well, but each has different benefits and installation considerations. You can also find a wide choice of composite options that are made using a composite plastic material that won’t rot.

Concrete gravel boards

Concrete gravel boards are a strong and durable choice for fencing projects. They are often used with concrete fence posts and panel fencing where a robust base is needed. 

Concrete gravel boards are resistant to rot and can stand up well to ground contact and wet conditions. This makes them a practical option for long-term fencing installations where the base may be exposed to moisture. 

They can be heavier to handle than timber gravel boards, so installation may take more care, especially on longer runs or sites with limited access. 

Timber gravel boards

Timber gravel boards are often chosen when a consistent timber appearance across the fence line is needed. They can work well with timber fence posts, feather edge fencing and traditional garden fencing. 

Timber gravel boards are usually easier to cut and handle on site than concrete options, which can be useful where the fence line includes corners, changes in level or bespoke sections. 

Because timber is exposed to outdoor conditions, treated timber gravel boards are usually preferred. Any cut ends should also be treated where required. 

Concrete vs timber gravel boards

The best gravel board type will depend on the project. Concrete gravel boards are often chosen for strength and durability, while timber gravel boards are often selected for appearance and easier handling. 

Concrete gravel boards may be better suited to projects where long-term resistance to ground moisture is a priority. Timber gravel boards may be more suitable where a natural timber finish is preferred, or where the fence is being built using timber posts and rails. 

It is worth considering:

• The type of fence being installed 

• Whether the posts are timber or concrete 

• The ground conditions 

• The finished appearance the customer wants 

• Site access and handling requirements 

• Whether boards need to be cut to size 

Common gravel board sizes

Gravel board sizes can vary depending on the fencing system and supplier, so you should always check the product specification before ordering. 

Many gravel boards are designed to suit standard fence panel widths, often around 1.83m wide. Heights can vary, with common options including 150mm and 300mm, depending on the required finish and ground conditions. 

Concrete gravel board sizes may also vary by profile and weight. Timber gravel boards can vary in thickness, width and treatment type. 

When choosing gravel board sizes, consider:

• The width of the fence panels or fence bays 

• The required finished fence height 

• Ground levels along the fence line 

• Compatibility with fence posts and fixings 

• Whether the board needs to be cut

If the site has uneven ground, a taller gravel board may help create a neater finish or reduce the need for extra cutting. 

How to install gravel boards

The installation method will depend on whether you are using concrete or timber gravel boards, as well as the type of fence posts and fencing system.

Before starting, mark out the fence line and check the levels. This helps you understand whether the gravel boards can run level, need stepping, or need to follow the slope of the ground.

1. Set out the fence line

Use a string line to mark out the position of the fence. Check boundaries, ground levels, access and any obstacles before digging post holes or setting posts.

2. Install or position the posts

Posts should be set at the correct spacing for the fence panels or fence bays. Make sure they are upright, aligned and set deep enough to support the finished fence. 

3. Fit the gravel boards

For concrete fence posts with slots, the gravel board can usually be lowered into position between the posts before the fence panel is fitted 

For timber posts, timber gravel boards are often fixed directly to the posts using suitable external-grade fixings. The board should sit level and be securely fixed before the rest of the fencing is installed. 

4. Check the level and alignment

A gravel board creates the base line for the fence, so it is important to check the level regularly. Small errors at the base can affect the appearance of the full fence run. 

5. Fit the fence panels or boards

Once the gravel boards are in place, the fence panels or feather edge boards can be installed above them. Make sure the timber is not sitting directly against the ground. 

Common installation mistakes to avoid

A well-installed gravel board can help protect the fence and improve the finished result. Common mistakes to avoid include:

• Choosing a gravel board that does not suit the fence system

• Not checking post spacing before ordering 

• Leaving timber panels in contact with the ground 

• Using untreated cut ends on timber gravel boards 

• Failing to check levels along the fence line 

• Using unsuitable fixings for outdoor use 

• Underestimating the weight of concrete gravel boards 

• Not allowing for changes in ground level 

Taking time to check the specification and site conditions before installation can help prevent delays and reduce the chance of rework.

Which gravel board should you choose?

For projects where strength, durability and moisture resistance are the main priorities, concrete gravel boards are often a practical choice. For fencing where appearance, easier handling and a consistent timber finish are more important, timber gravel boards may be more suitable.

The right option depends on the fence type, posts, ground conditions and finish required. You should also consider gravel board sizes, installation method, access to site and whether the boards need to be cut on site. 

Choosing suitable gravel boards helps protect the fence, improve the final appearance and reduce the risk of timber sitting directly on the ground.

Gravel board FAQs

What is a gravel board used for?

A gravel board is used at the base of a fence to help protect timber panels or boards from direct contact with the ground. It can also create a neater finish along the fence line.

Are concrete gravel boards better than timber gravel boards?

Concrete gravel boards are often more durable and resistant to ground moisture and insect damage. Timber gravel boards are usually easier to handle and can provide a more natural timber finish. The best option depends on the project.

What sizes do gravel boards come in?

Gravel board sizes can vary, but many are made to suit standard fence panel widths. Common heights include 150mm and 300mm, depending on the fencing system and required finish, and lengths can range from 1.8m to 4.8m.

Can gravel boards be used with feather edge fencing?

Yes, gravel boards can be used with feather edge fencing to help protect the bottom of the boards from ground contact and moisture.

How do you install gravel boards?

Gravel boards are usually fitted between or onto fence posts before the fence panels or boards are installed. The method depends on whether the project uses concrete posts, timber posts, concrete gravel boards or timber gravel boards.

Final thoughts

Gravel boards are a useful addition to many fencing projects, helping to protect the base of the fence and create a cleaner finish. Concrete gravel boards are a strong option for long-term durability, while timber gravel boards can suit projects where a natural timber appearance is preferred.

By choosing the right type, size and installation method, contractors and landscapers can help improve the lifespan and appearance of the finished fence.