Designing Spaces That Reflect You
how to install rim joist on deck

How to Install Rim Joist on Deck [A Step-by-Step Guide]

Looking for answers how to install rim joist on deck? The rim joist is an important part of your deck. Basically, the rim joist is the frame running around the circumference of the deck. It serves as a support for the boards and beams that hold the deck in place.

Depending on the situation, there are a few various ways to install rim joists. Below we will cover how to install rim joists when building a deck.

1. Measure the Deck’s Circumference

Measure the Deck's Circumference

To begin, you’ll need to measure the perimeter of the deck. This will help you to determine the amount of lumber that you need for the rim joists. 

You should begin by measuring the length of the sides of the deck. After that, add up the total length. Make sure to account for the corners of the deck. 

It is fair to say that measuring the deck perimeter is an essential step when you’re planning to build your rim joist. To measure the perimeter of your deck, you will need; a measuring tape, a pencil, and paper to record the measurements on. 

Here are the steps that you to follow:

  • Start by measuring the length of each of the sides of the deck. If the deck is in a rectangular or square shape, measure the length of each side and add them up.
  • If your deck has any angles and curved sides, measure them separately. You should use a measuring tape to follow along the contours as you carefully record the length of each section.
  • Make sure to measure all corners in the deck accurately. For example, if your deck has a 90-degree corner, measure both sides of this corner and add them up to get the total length.
  • Once you have measured all the sides or sections of the deck, add up the total length to get the perimeter. You should remember to note this measurement on your recording paper.

To ensure accuracy, you should take the time to double-check your results by going around and measuring again. If you get different results, take the average of your two results if you want to get a more accurate estimate. 

However, if the difference is big, measure a third time and get the average of the three results. Now, you can use this measurement to calculate the amount of lumber you will need.

2. Choose the Rim Joist Material

how to install rim joist on deck

When it comes to choosing the material for your rim joist, you have a few options. Most people go for pressure-treated lumber. It is a popular choice because of its resistance to rot and decay. However, it can be more expensive than other types of wood because of the additional costs incurred when treating it. 

Alternatively, you can use cedar, redwood, or other types of wood. While they may not be treated, they are naturally resistant to decay. The best way to go about it is to visit your local store and get the expert advice of the attendant. The staff usually has enough experience in this field to know what works best with various deck designs.

3. Cut the boards for your rim joist to the right size

Cut the boards for your rim joist to the right size

Cutting the rim joist boards to length is the third step in the construction of a deck. Because the rim joist boards are the outermost parts of the deck, it is essential that you cut them to the correct length to ensure that the deck has a sound structure.

When cutting the boards, cut them in such a way that they fit tightly against the posts of the deck. This will help ensure that the deck is stable and properly held in place. If the boards are too long, you can trim them later. Nevertheless, it is better to play it safe and cut them a bit shorter than needed. This will conveniently leave room for any adjustments.

After cutting the rim joist boards to length, you will need to attach them to the deck posts carefully. This can be done using a variety of methods. You can use lag bolts or deck screws. The method you choose depends on the materials and design of your deck. 

If you cut the boards right and follow the proper installation process, the rim joist boards will provide a solid foundation for your deck. 

4. Installation


Once you have cut your rim joist boards to the correct length, it’s time to begin the installation process. This is where the fun begins because you begin to see your rim joists taking shape. 

Framing A Floor 🚧 Rim Joists 👷 Floor Joists

You should begin by fixing the first rim joist to the deck post using galvanized nails or screws. It’s important to use galvanized fasteners as they are resistant to rust and corrosion. You should avoid anything that will rust because this will cause problems with your deck in the future.

Before attaching the rim joist to the deck post, pre-drill the holes. Drilling into the wood without pre-drilling might split the wood and compromise your work. Use a drill bit that is slightly smaller than the diameter of the nails or screws you will be using for your pre-drilling. This will help to ensure that the fasteners go in smoothly.

After pre-drilling the holes, you can now attach the rim joist to the deck post. You should make sure that the rim joist is level with the top of the deck post. This brings us to the next step.

5. Levelling


When building a deck that requires framing, leveling the rim joist accurately is very important. Use a level to determine whether the first rim joist is level. If it is not level, you should adjust the placement of the nails or screws. Repeat this process for all the rim joists.

To do level leveling, you will need a level. A level is a tool that helps you to determine if a certain surface is horizontal or vertical. You should place the level on top of the rim joist and slowly adjust the placement of the nails or screws until it is level.

It is important to remember that if the rim joist is not level, it can cause problems with the structure’s overall stability. This will also affect the appearance of your deck. Therefore, make sure that the rim joist is level before proceeding with the rest of the construction process.

6. Attach all the rim joists to the deck post

Attach all the rim joists to the deck post

Now, attach the remaining rim joists to the deck posts in the same way as you attached the first one. Make sure that all the boards fit quite loosely against the posts of the deck.

To attach the rim joists, first measure the distance between the first rim joist and the next post. This will help to determine the length of the next rim joist. You should use a measuring tape to measure. Now cut the rim joist to length using a saw. Make sure the cut is straight and as clean as possible.

Next, position the rim joist against the deck post so that it is level with the top of the frame of the deck. You should use clamps to hold the rim joist in place as you go about attaching it to the post.

Now insert your screws into the pre-drilled holes. Tighten the screws, one by one, using a screwdriver or a drill. Make sure that as you drive the screws, they are level with the surface of the wood. You should repeat this process for all rim joists.

It is important that you take your time when measuring to ensure that everything will fit together properly.

7. Getting the corners right

Getting the corners right

This step begins with measuring the length of the rim joists from where they meet at the corners. Use a measuring tape for an accurate measurement.

You should cut a 2×4 piece of lumber for each corner. Position the lumber against the end of one of the rim joists. You should make sure it is level with both the top and side of the joist. Check whether this lumbar is level with the rim joist and position it such that it extends past the corner of the rim joist. Now use a drill and screws to attach the lumbar to the rim joist.

Repeat this process for all the corners. You should make sure each piece of the lumber is level with the top and side of the rim joist.

Once all lumbar pieces are attached to the rim joists, nail your corners together. You should use nails that are long enough to penetrate both pieces of wood so that they can secure them together.

Nailing or screwing the rim joists together ensures that they are securely fastened. This way they will not shift or move in a way that will undo your structure.

8. Check for level

Check for level

Ensure all the joists are level and square once again. The level is the evenness of the surface of the deck. Squareness, on the other hand, refers to the correctness of the angles of the deck. If the deck is not level or square, it can cause problems with the stability and durability of the structure. This can pose safety risks.

To check for squareness, measure the diagonals of your deck. You should measure from one corner of the deck to the opposite corner, and then measure from the other corner to the opposite one. These two measurements will be equal if the deck is square. 

If the measurements are not equal, then the angles of the deck are not correct. You need to make adjustments until you get equal measurements for the distance between the opposite corners.

When making corrections for the levelness or squareness, adjust the rim joists by adding shims or by cutting until they are level and square. While checking for levelness and squareness may seem like a small step, it’s an important aspect of the process that will prevent structural issues later on. 

It’s easier to make the necessary adjustments before the deck is fully built than to fix problems down the line.

9. Finish the Rim Joist installation process

Finish the Rim Joist installation process

Finally, finish the process by trimming any excess wood and sanding the edges from your rim joists. This gives the deck a beautiful, polished appearance. You should apply a sealant or stain to the rim joist to protect it from the elements of decay and rust. This will ensure that your rim joists and in turn the deck will last for years to come. Now you guess how to install rim joist on deck.

Final Thoughts how to install rim joist on deck

In conclusion, how to install rim joist on deck is a relatively simple process that is accomplished with a few basic tools and materials. By following these easy steps, you will ensure that your deck is strong, level, and safe for use. 

If you’re not comfortable undertaking any of these steps yourself or you don’t have the necessary tools to create and install rim joists to your deck, it’s always best that you consult an expert. At the end of the day, it is better that you hire the services of a professional than design substandard rim joists or install them wrongly to your deck. 

On the other hand, if you do not have the necessary tools to create rim joists and attach them to the deck, you can get an expert to do it for you. This is because you will find that the cost of acquiring the necessary tools outweighs what you will pay someone with all the tools to do for you. now you know how to install rim joist on deck.


Related Post