How to Join Two Boards Lengthwise – Side By Side

In carpentry, one of the hurdles that woodworkers face is ‘How to Join Two Boards Lengthwise?

Bringing your imagination into the existing product is a real game. One of the major challenges in woodworking is edge joining. It is necessary for every carpenter be it beginner or professional to get hands-on this skill to add more accuracy to their work.

Every person has a different style of working. But there are four basic techniques of getting the work done. Most professionals use them and you can also use them as a standard to join two boards side by side. In this guide, you’ll learn the correct combination of tools and techniques to increase your work accuracy.

how to join two boards lengthwise

4 Basic Techniques on How to Join Two Boards Lengthwise

1. Joining Without Nails

Joining boards with glue is the most convenient method. All you need for this method is wood glue with strong adhesive power. Place both the boards side by side and clean the surface where you intend to apply the glue. You can use the chalk markers as well for the accurate alignment of the boards. Then place the one board on the other precisely in a way that it equalizes the edges. Now rinse off the extra glue and let it dry to get the firmness. 

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Required Materials:

  1. Boards to be joined
  2. Wood adhesive or glue
  3. Chalk Markers
  4. An extra cloth to remove the glue. 

Sequential Guide On Joining Without Nails

i. Arrangement of Boards:

The most crucial part of joining boards is to arrange and mark the boards. Lay down the boards on a clean surface. Now adjust them side by side keeping them per the correct pattern and shades. After alignment, draw any sign or a U with the help of a chalk marker. The mark will help you track the correct points to be joined after the glue is applied.

ii. Adhesive Application:

After the alignment is done, now is the time to apply the glue or any sticky material you have selected for the procedure. Pick up one of the boards and apply the glue on the entire side of the board. Make sure you do justice with the amount of glue. It should not be less or more than the requirement otherwise it will affect the firmness.

iii. Clamping The boards:

Now slide the board back carefully following the chalk guides. Once you’re satisfied with the alignment, clamp the boards together by exerting some force. The clamping will help the glue to spread evenly. Allow the glue to dry off so that the two join of the two wood planks is strong and they hold together.

iv. Wipe off the extra glue:

The final step of the process is to clean the extra glue spilling out of the boards. This will give the boards a clean attached look. And if you leave the glue uncleaned, it will affect the finishing.

Pros and Cons of gluing the wood Boards together


  • This is the cheapest and easiest method
  • You don’t require some special kind of tools or expertise to do this.
  • All you need to be cautious of is the correct alignment and enough amount of glue applied.


  • Using this technique with modern wood can be challenging
  • Considering the weight of the wood, if it is not clamped properly, can cause wood molding from the joints.

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2. Kreg jig Method

Kreg jig method is a quick method to join wood planks. Unlike the glue joint method, there is no need to wait for the glue or any material to dry. This technique is incredibly fast and easy. You have to drill a hole in one wood board and attach it to the other with the help of self-tapping screws.

Required Materials:

  1. Kreg jig
  2. Wood boards
  3. Clamps
  4. Screws 
  5. Cordless drill

Sequential Guide on Kreg jig Method

i. Measurement of the wood boards:

Lay down the wood boards on a clean surface. Measure the width of the board and adjust the depth collar of the drill according to that. This will ensure accuracy in the measurement of the pocket hole. Then lift the precise guide hole relative to the pocket hole.

ii. Wood Clamping and Drilling:

The next step is the wood board clamping. Then start drilling into the guide holes keeping in view the alignment of the planks. You can drill two to three sets of pocket holes to attain maximum firmness.

ii. Finishing of Joints:

The final step is to join the boards. Put the drilled one aligned to the other one and start drilling and inserting screws. Keep on drilling until you reach the second wood and flush inside the pocket hole. 

Pros and cons of Kreg jig Method


Joining boards with Kreg jig is one of the convenient ways to get the job done. You can create solid joints. The metal screws can make the task easier and effective if you have the right pocket hole-creating tool.


It is mostly used for tough and hard boards. For that, you need to have some specialized pocket hole makers. These tools aren’t used for any other task more often, making the worker give it a second thought before adopting this joining method. Because these specific tools can be heavy on the pocket sometimes.

3. Dowel Method

Dowel joinery allows you to join wood planks creating small woodcuts called dowels. The dowels are then inserted in the holes matching the perfect-sized holes. It creates a tension point between both boards. This method provides a stronghold in the wood joining. 

Required Materials:

Dowel joinery allows you to join wood planks
  1. Wood Planks
  2. Cordless drill
  3. Drill bits
  4. Ruler and Pencil
  5. Ready-made dowels
  6. Clamp

Sequential Guide On Dowels Method

i. Identify Dowel Spots:

Start by measuring them and pointing out the spots where you want to fix the dowels. Pre-mark the points at an equal distance using the pencil and ruler. While marking the points, consider the depth and length of your planks and do the job precisely. Even a minor mistake can affect the accuracy of the work.

ii. Start the drilling work:

Take a drill test first to check if you do it right. Make sure you choose the diameter of your drill bit accurately as per your dowel. Then mark the drill bit at half of the length of your dowel’s length. Start drilling the hole and try to fit in the dowel when the drilling is done. 

Now when your test drill is completed and you’ve got the exact measurement of dowel holes, start completing the rest of the drilling. Insert all the dowels in their respective holes firmly and you’re good to go.

ii. Final Fixing:

The final step is the dowel fixing with the adhesive application. Align the planks accurately and lay them down at the desired place. Apply the glue on dowels and insert them into the drilled holes. You might have to exert some extra force using a mallet. Once the dowels are fixed, leave them for a few minutes so that the glue drys and becomes firm.

Pros and Cons of Dowel Joinery


One of the key advantages of using this technique is that it requires no specialized tools. You can get the job done with all of your ordinary woodworking tools.


The precision in the measurements and drilling is important. It’s better if you practice this method on some spare wood before starting off working on your main project. 

4. Biscuit Joining

Biscuit joining is the least useful or popular technique of board joining. You first have to cut football-shaped wooden pieces called biscuits. Then they are inserted into the channels after creating tension between both the planks.

Required materials:

  1. Wood Planks
  2. Biscuits
  3. Biscuit jointer
  4. Measuring tape
  5. Clamp
  6. Spray water bottle

Sequential Guide On Biscuit Joining Method

i. Alignment and marking of planks:

Align the planks per their sequential pattern and shades. Then mark the positions where biscuits are to be inserted. You can use the measuring tape for accuracy. Mark the half of the width of the biscuit that you’re trying to fit in. Then mark the biscuit from the point where it touches the wood. Now mark the biscuit after flipping. These markings would be your guidelines for the accurate insertion of the biscuits into the planks.

ii. Cut and set the joiners:

Once you’ve got the points where to cut, set the biscuit joiner as per its adjustments. Fix it to cut into half of the biscuit’s width. Start making the cuts to join the biscuits.

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iii. Biscuits Insertion:

Now that the cutting is done, start inserting the biscuits into the planks. Adjust them to one of the planks accurately. Then join it to the second plank and spray water over it so that it fits in the space properly. Leave it for some time for the biscuits to achieve their maximum firmness and fitness.

Pros And Cons of Biscuit Joiner


This technique can be ideal to fix already bowed planks because it offers great support. They work on the phenomena of creating tension that makes it more usable.


It takes a lot of effort to cut the wood and then insert it precisely, making it harder for a worker to adopt. They are not ideal for creating much pressure that is not very suitable for joints bearing much weight.

Final Verdict On How to Join Two Boards Lengthwise

How to join two boards together

It depends on your choice of whatever method you want to use to join the boards. Some of the methods use specialized tools that cost extra. Some need the expertise to get the desired results.

But it wholly relies on your project nature and your creativity as well. You can take help from the above guide to go for the best technique for your project as per your requirement.

FAQs-How to Join Two Boards Lengthwise

1. How to join two boards side by side?

Joining two boards side by side can be a tough job at times. Accuracy and precision of cuts and joints matter a lot in joining. There are four basic techniques through which you can get the job done accurately.

  1. Joining Without Nails (with wood glue)
  2. Kreg jig Method
  3. Dowels Method
  4. Biscuit Joining

You can use any of these methods at your convenience and requirement.

2. How to join two boards together?

Ans. You can use the following simple steps on How to Join Two Boards Lengthwise

  1. Align boards together.
  2. Mark the points to be joined with chalk 
  3. Pick one of the boards and apply glue on the other
  4. Now put back the second board and clamp them both together.
  5. Wipe off the extra glue and let it dry.

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