Drywall Flat Boxes – Should You Be Using One?

Using a drywall flat box

If you’re about to start putting up some drywall or thinking about becoming a drywalling professional, getting the right kit for the task in hand can be challenging – especially if you’ve little-to-no experience in the field already.

That said, you’ll be pleased to hear there is a range of automatic drywalling tools that have been specifically designed to make your life quicker and easier. With years of design and development behind them, these tools are must-haves if you want to drywall effectively.

One of those tools is the drywall flat box.

What Is A Drywall Flat Box?

Once your drywall has been put up, you’ll want to start covering the joints between boards with a combination of tape and joint compound to leave a smooth finish across the entire surface of your wall. You can do this by hand or by using an automatic taper for speed and efficiency.

After the tape and compound have been applied, this is where your flat box comes in.

Drywall flat boxes come in various sizes (including 7”, 10” and 12”) and is run over each joint in turn, trowelling the compound and feathering the edges for a precise crown. They are used to ensure more consistent results and a smooth finish across all drywall joints. The box is designed as a device that will make your drywalling life easier and the job of covering joints much quicker to complete.

We think that once you’ve used a drywall flat box, you won’t want to go back to doing the job manually!

How To Use A Drywall Flat Box

Take a look at our drywall flat boxes to see what exactly we’re talking about here.

The flat box in itself isn’t a complicated tool to use, but mastering its delivery of compound in a smooth and consistent way will take practise. The box is filled with joint compound and this pushes the hinged pressure plate forward – this in turn forces the joint compound out through a slot on the face panel.

The adjustable crown setting dial gives you the freedom to amend how quickly the joint compound is pushed through the slot, meaning you can change the amount of joint compound being used between applications.

When you start to work on your drywall, the compound flows out of the slot in the face plate and a steel blade then smooths it to ensure a consistent finish throughout the application.

As you use your drywall flat box, make sure you lay the box wheels and blade flat against the joint. Then, release the brake lever which is located at the bottom of the handle and put consistent pressure onto the face plate as you move the box across the length of the joint.

Remember to keep the handle angled at 45 degrees to deliver the best finish possible. Also, make sure you start at the end of the joint and work in towards the middle – to finish a vertical joint, start at the bottom, work to the middle and then from the top down.

Last but by no means least, when you remove the drywall flat box from the wall, do this in a smooth sweeping motion to avoid leaving clumps of compound on the joint.

Reasons To Use A Drywall Flat Box

There are a number of advantages to using a drywall flat box, much in the same way as using an automatic taper. These benefits include:

  • Complete joint finishing quicker and more efficiently
  • Finishing with the flat box requires significantly less physical effort than finishing by hand
  • Easier to finish joints in hard-to-reach areas
  • Work safer, without the need for ladders or plastering stilts
  • Enjoy a smoother, cleaner finish on every joint
  • Save both time and money with less room for error


If you only need to drywall one site or the job is relatively small, you might feel that investing in a drywall flat box isn’t necessary. Flat boxes require regular maintenance and cleaning after each use, so while it could be a pain for small sites, it could be a blessing for any larger drywall jobs.

We offer a selection of drywall flat boxes including the Columbia Fat Boy Box and the Level 5 Mega Flat Box – you can take a look at the full range here.

Order your drywall flat box online today!