Today, we will dive into the intriguing world of jointing compound and plaster. These two materials play a significant role in house decorating, and understanding their differences is crucial for any DIY enthusiast. In this post, we’ll explore what jointing compound and plaster are, highlight their distinctive features, and guide you through their specific applications. So, put on your DIY hat, grab a cuppa, and let’s unravel the mystery together!

What is Jointing Compound?

Jointing compound, often called filler or mud, is a versatile material primarily used for filling gaps, cracks, and joints in plasterboard or drywall installations. It’s specially formulated to provide a smooth and seamless finish while reinforcing the integrity of the wall. Jointing compound is available in ready-mixed or powder-based forms, offering convenience and flexibility for various projects.

What is Plaster?

Plaster is a building material with a long history, dating back centuries. It consists of a mixture of gypsum, sand, and water, forming a paste that can be applied to walls, ceilings, and other surfaces. Plaster has been widely used for creating decorative finishes, repairing damaged surfaces, and providing a solid foundation for paint or wallpaper.

Composition and Application

Jointing Compound

Jointing compound typically comprises gypsum powder or a similar compound mixed with water and other additives to enhance its workability. The ready-mixed variant comes pre-mixed and ready to use, saving time and effort. On the other hand, powder-based jointing compound requires mixing with water to achieve the desired consistency. Jointing compound is primarily used for filling joints and cracks between plasterboard sheets, creating a smooth and even surface for painting or wallpapering. Although these days, it’s common to see jointing compound applied over whole walls to smooth them out. Jointing compound can be sanded after it dries for a smooth finish, which is perfect for DIYers looking to fill in a few bits of the wall themselves.

As a DIYer, I find jointing compound great for filling cracks and finishing plasterboard. We have also fairly recently used it all over walls instead of plaster in a room after discovering this is possible from some YouTube tutorials. Unfortunately, the walls in this room are already showing cracks, and it hasn’t even been a year yet! For this reason, I do not recommend jointing compound as a replacement for plaster or plasterboard – instead, think of it as on par with filler.


Plaster, in its traditional form, is made by heating gypsum to remove its water content, creating a fine powder. When mixed with water, the powder rehydrates, forming a workable paste. Plaster is commonly applied in multiple coats, building up a thick layer over a framework of laths (thin strips of wood) or a solid base. It can be used to create decorative finishes, repair damaged surfaces, or achieve a smooth and stable surface for painting or wallpapering. Plaster does not sand, so you really must ensure a good quality finish during the application process. There’s little room for error.

As a DIYer, I prefer to use plaster to fill large areas of the wall that cannot be fixed with filler. I always underfill and once the plaster dries, top it up with jointing compound. Once the jointing compound is dry, I sand it down to get a smooth finish.

Key Differences

  1. Application Areas: Jointing compound is specifically designed for filling joints, gaps, and cracks in plasterboard or drywall installations. It is primarily used on flat surfaces, providing a seamless finish before painting or wallpapering. Plaster, on the other hand, has a broader range of applications. It can be used to create decorative mouldings, cover uneven or damaged walls and ceilings, and achieve a more substantial base for paint or wallpaper.
  2. Working Time: Jointing compound has a shorter working time compared to plaster. It dries relatively quickly, allowing for efficient progress during the application process. Plaster, however, has a longer working time, which provides more flexibility for shaping and smoothing the surface before it sets.
  3. Strength and Durability: Plaster is generally stronger and more durable than jointing compound. It forms a solid layer that can withstand impact and wear over time. Jointing compound, although it adds strength to joints, is not as sturdy as plaster and is better suited for filling and smoothing purposes rather than providing structural support.
  4. Thickness: Plaster is often applied in thicker layers compared to jointing compound. It is built up in multiple coats to achieve the desired thickness, while jointing compound is typically applied in thinner layers, focusing on filling and levelling the joints between plasterboard sheets.
  5. Difficulty of application: Plaster is not sandable, so the application finish must be perfect to look professional. This is difficult to do and requires practice to learn. Jointing compound can be sanded after it has dried, making it much more suitable for DIYers. 


We’ve journeyed through the world of jointing compound and plaster, uncovering their distinct characteristics and applications. Jointing compound excels at creating seamless finishes on plasterboard or drywall surfaces, while plaster offers a versatile solution for repairs, decorative finishes, and solid foundations. By understanding the differences between these materials, you’ll be better equipped to confidently tackle your DIY projects.

Remember, each material has its unique purpose and benefits. Whether you choose jointing compound or plaster depends on the specific requirements of your project. So, put on your DIY hat, gather your tools, and let your creativity flow as you transform your living space with the right choice of material!

About The Author

  Hi, I'm the author of this small DIY blog (❁´◡`❁)

I've been making things my whole life out of all sorts of materials but since buying my first house in 2019, I fell in love with woodwork and DIY. I didn't have a big budget to renovate so had to make do with as few inexpensive tools as possible. Fed up with big blogs that showcase amazing DIY and woodwork projects that I couldn't recreate without power tools, I started this blog for creative people without creative budgets. Here, I showcase my home renovating and woodworking projects as well as write about DIY and woodwork tips from my personal experience.

Thanks for reading!!!

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