Filler: create a beautiful smooth finish

by Joost Nusselder | Updated on:  June 19, 2022
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Filler is a material that’s added to the surface of another object to make for a smoother surface, usually to apply another type of finish over it like paint or a veneer (here’s how to paint it).

A wall filler is a material that is used to fill in gaps or cracks in walls. It can be made from a variety of materials, including plaster, wood, metal, or plastic. Wall fillers are typically used to improve the appearance of walls and to make them more durable.

Construction filler is a material used to fill in gaps and cracks in the structure of a building. In this article, I’ll explain how it’s used and how to choose the right one for your project.

What is filler

What Exactly is Joint Filler in Construction?

Joint filler is a compound used to fill the gap between two parts of a structure or two identical structures. It is a material that is used to fill spaces, gaps, and cracks in concrete sections. The joint filler is used to satisfy the need for a satisfactory filling material that possesses adequate compression and expansion properties.

The Usage Areas of Joint Filler

The usage areas of joint filler are quite wide. Here are some of the most common areas where joint filler is used:

  • Ceramic tiles
  • Concrete structures
  • Expansion joints
  • Filling gaps between edges of two structures
  • Filling spaces between two identical structures

Types of Joint Fillers in Construction

When it comes to joint fillers, there are a wide range of materials that can be used. Some of the most commonly used materials include:

  • Rubber
  • Asphalt
  • Polymer
  • Compound

Benefits of Using Joint Fillers

Using joint fillers in construction has a wide range of benefits, including:

  • Preventing water from entering the joint
  • Preventing other materials from entering the joint
  • Increasing the thickness of the joint
  • Smoothing out the edges of the joint
  • Adding value to the overall structure

Preparation Steps for Applying Joint Fillers

To ensure the best possible results when applying joint fillers, there are a few important steps that need to be followed:

  • Clean the joint thoroughly
  • Check the edges of the joint to make sure they are solid
  • Confirm the thickness of the joint
  • Mix the joint filler material according to the manufacturer’s instructions
  • Apply the joint filler to the joint using a smooth, wet edge
  • Allow the joint filler to dry fully before continuing work on the structure

Prominent Brands and Products

There are a number of different brands and products available when it comes to joint fillers. Some of the most popular and well-known brands include:

  • Sikaflex
  • 3M
  • Dow Corning
  • Tremco

When choosing a joint filler product, it’s important to consider factors such as the type of joint being filled, the materials being used in the construction, and the overall quality of the product.

Other Types of Wall Filler

When it comes to filling small holes or cracks, lightweight fillers are a great option. These materials are usually made from a compound of water, abrasive, and fine particles, which makes them easy to apply and smooth out. They are highly versatile and can be used on a wide range of surfaces, including drywall, stone, and wood.

Hard Fillers

For more serious damage, hard fillers are the best type of material to use. These compounds contain a polymer that makes them highly durable and able to withstand a great deal of wear and tear. They are ideal for internal walls and can be used to cover large areas without leaving any damage.

Wet Fillers

Wet fillers are another type of material that is available for professional use. These compounds require a wet tool to apply, and they are highly effective at increasing the ability to transmit electromagnetic signals. This makes them ideal for increasing the level of value and extra features in a building.

Thin Fillers

Thin fillers are a great option for achieving a tight, smooth finish. They are available in a wide range of sizes and can be used to cover large areas without leaving any damage. They are highly versatile and can be used on a wide range of surfaces, including drywall, stone, and wood.

Extra Value Fillers

Finally, extra value fillers are available for those who require a little extra from their filler materials. These compounds contain a polymer that makes them highly durable and able to withstand a great deal of wear and tear. They are ideal for internal walls and can be used to cover large areas without leaving any damage.

Choosing the Right Filler Material for Your Construction Project

When it comes to selecting the right filler material for your construction project, there are several key factors to keep in mind. These include:

  • Material properties: The type of material you choose will depend on the specific needs of your project. For example, if you need a lightweight filler for a vertical application, you may want to consider a foam-based product. On the other hand, if you require a strong, durable filler for a bridge or other heavy-duty application, a steel-based product may be the best choice.
  • Design requirements: The design of your project will also play a critical role in determining the type of filler material you need. For example, if you are working with large slabs or require a smooth, even finish, you may need a self-leveling filler that can be easily applied and smoothed out. Alternatively, if you are working with multiple joints or require additional control over the setting process, a traditional filler material may be more appropriate.
  • Operator expertise: The skill level of your welding operators will also be a critical factor in determining which filler material to use. Some products require more expertise to work with than others, so it’s important to choose a product that your operators are comfortable and experienced with.
  • Mechanical and chemical properties: Finally, it’s important to consider the mechanical and chemical properties of the filler material you choose. This will ensure that the final product is strong, durable, and able to withstand the elements over the long term.

Types of Filler Materials

There are several different types of filler materials available for construction projects, each with its own unique properties and uses. Some of the most common types include:

  • Steel-based fillers: These products are typically used in heavy-duty applications where strength and durability are critical. They can be utilized in both vertical and horizontal applications and come in a variety of sizes and forms.
  • Foam-based fillers: Foam-based products are lightweight and easy to work with, making them a great choice for vertical applications. They can also be used to improve the thermal and acoustic properties of a building.
  • Self-leveling fillers: These products are designed to be applied quickly and easily, resulting in a smooth, even finish. They are typically used for large slabs or other applications where a level surface is critical.
  • Traditional fillers: Traditional filler materials, such as cement or plaster, are still widely used in construction projects. They offer a lower cost option and can be used in a variety of applications.


So, filler is a material used to fill gaps and cracks in construction. It’s important to choose the right material for the job, and you should consider the type of material, the structure, and the purpose of the construction. 

You can’t go wrong with a good filler now that you know all the ins and outs. So, don’t be afraid to use one when you need to!

I'm Joost Nusselder, the founder of Tools Doctor, content marketer, and dad. I love trying out new equipment, and together with my team I've been creating in-depth blog articles since 2016 to help loyal readers with tools & crafting tips.