How to Keep Split King Mattresses Together

A split king mattress offers unparalleled comfort and flexibility for couples, allowing each partner to customize their side of the bed to their preferred firmness and support level. However, one common challenge that arises with split king mattresses is the tendency for the two twin XL mattresses to shift apart, creating an uncomfortable gap in the middle.

This gap can be frustrating and disruptive to a good night’s sleep, as it not only affects the overall comfort but can also lead to discomfort caused by the separation of the mattresses. Fortunately, there are several effective methods on how to keep split king mattresses together, ensuring that you and your partner can enjoy a restful and undisturbed night’s sleep.

How to Keep Split King Mattresses Together

In this article, we will explore various practical solutions and strategies to prevent your split king mattresses from separating, allowing you to maintain the harmony of a single, cohesive sleeping surface. Whether you’re dealing with an existing issue or simply want to be proactive, these tips will help you create a more comfortable and harmonious sleep environment.

What is Split King Mattresses?

Split King mattresses are two twin-sized mattresses side by side. They are specially designed to be placed together on the same bed frame in order to form a king size mattress. Split King mattresses can provide comfort and convenience for couples who have different sleeping preferences or body types, such as one partner who prefers a firmer mattress while the other prefers a softer one.

When purchasing a Split King mattress, there are many important factors to consider in order to ensure the best experience possible. One of the most important aspects is making sure that the mattresses stay together throughout the night.

Importance of Keeping Split King Mattresses Together

Having two split king mattresses can make a big difference to one’s sleep comfort. They are usually most comfortable when kept together, as the edges of the mattress stay aligned and there is less risk of any shifting or sliding while sleeping on them.

Using an Adjustable Base

Keeping two separate split king mattresses together is also important for keeping them from becoming lumpy over time. The extra support provided by both sides of the mattress prevents uneven wear and tear, extending the life of the mattresses.

It is also important to keep split king mattresses together for safety reasons. If one side of the mattress slides off or shifts while someone is sleeping on it, they risk injuring themselves. Keeping them securely in place helps to ensure beds remain stable and safe at all times.

There are several methods for keeping split king mattresses together, including using straps or brackets to secure them in place. It is important to make sure these straps or brackets are securely attached and compatible with the size of the mattress. They should also be checked regularly to ensure that they remain securely fastened and able to keep the two halves of the split king mattress together.

10 Steps How to Keep Split King Mattresses Together

Step 1. Measure the Bed Frame

The first step in keeping your split king mattresses together is to measure the bed frame. You want to make sure that the frame is wide enough to accommodate both mattresses, as well as any additional components you may need for your setup.

If the frame is too narrow, you will need to purchase an additional frame or platform bed specifically designed for split king mattresses. Be sure to measure the length and width of your frame, as well as the height from the floor. This will ensure that you find a split king mattress that fits perfectly in your bed frame.

Measure the Bed Frame

Step 2. Purchase a Split King Mattress Connector

Once you have determined that your bed frame is wide enough, the next step is to purchase a split king mattress connector. This device connects the two halves of your split king mattress together, creating one large mattress surface and ensuring that they stay in place while sleeping or sitting on them. It also helps to reduce motion transfer between the two halves.

These mattress connectors are typically made of a durable material such as velcro or elastic, and some models even come equipped with straps or buckles for extra security. There are several varieties available on the market, so it is important to read customer reviews and research features before making your purchase.

Step 3. Attach the Connector

After purchasing a split king mattress connector, it’s time to attach it to the two halves of your mattress. Make sure that all four corners are securely connected before continuing with the installation process.

If you’re having difficulty connecting the two halves of the mattress, consider taking off your bedding before attempting to attach the connector. This will make it easier to access and line up the two sections of the mattress together correctly. Once each corner is connected, use a ratchet strap or bungee cords to hold them firmly in place.

Step 4. Place Your Mattress on Your Bed Frame

Now that your connector is securely attached, it’s time to place your mattress onto your bed frame. Make sure that each side of the mattress is properly aligned with its corresponding side of the bed frame and that no gaps exist between them once they are in place. Additionally, it’s important to ensure that the connector is still firmly affixed and not being strained by the two sides of your mattress.

Once both sides are properly in place, you can use one of several methods to keep them together. If your bed frame has slots or holes where a strap or bungee cord can be attached, you can lace one through the slots to keep the two sides together.

Split King Mattress Connector

Step 5. Secure Your Mattress with Straps

To ensure that your split king mattresses remain secure and stay together while you sleep, it’s important to use straps or bands around each side of them when placing them on your bed frame. This will help keep them from shifting or slipping out of alignment while you sleep or sit on them.

Additionally, it will help to prevent the edges from separating and creating a space between your mattresses. It’s essential to use the right straps or bands that are designed specifically for split king mattresses in order to ensure they stay secure and don’t move around. Many bed frame manufacturers offer these types of straps, and they can be found online or in most home furniture stores.

Step 6. Place a Mattress Pad Over Both Halves

Once you have secured your mattresses with straps, it’s time to place a mattress pad over both halves of them for added comfort and protection against wear and tear over time.

Be sure to choose a pad specifically designed for split king mattresses so that it fits properly over both halves without bunching up in any areas or leaving gaps between them where air can escape through during use. Mattress pads come in a variety of materials, so determining which one best suits your needs is essential.

Step 7. Use an Adjustable Base

Using an adjustable base with your split king mattresses can also help keep them in place while sleeping or sitting on them by providing support along their entire length and width when adjusted accordingly. This type of base also offers other benefits, such as reducing back pain and improving circulation throughout the body while sleeping, which can lead to better overall health and well-being over time.

Step 8. Consider Adding Locking Wheels

If you plan on moving around often with your beds, then consider adding locking wheels onto each half of your split king mattresses for added stability when transporting them from one location to another safely without damaging either half in any way shape, or form during transportation.

This is especially helpful if one or both halves of your split king mattresses are particularly heavy and cumbersome to move around. Locking wheels can also help keep your beds securely attached when used in the same location, as they will prevent any accidental movement or separation when two halves are locked together.

Mattress Pad Over Both Halves

Step 9. Keep Your Mattress Clean and dry

Finally, make sure that you always keep both halves of your split king mattresses clean and dry at all times by vacuuming regularly and spot-cleaning any spills immediately upon occurrence using mild detergents only meant for use on fabric surfaces such as those found on most modern-day mattresses today.

Step 10. Replace Your Mattress Every 8-10 Years

To ensure maximum comfort levels along with optimal performance from both halves of your split king mattresses, be sure to replace each one every 8-10 years, depending upon usage levels throughout their lifetime. Look for models that are specifically designed for split king and dual mattresses, as these will provide the best level of support to keep them together.

Additionally, check each mattress regularly for any signs of wear and tear, such as sagging or indentation in the foam layers that may be causing your two halves to pull apart.

Things to Consider When Keeping Split King Mattress Together

When trying to keep split king mattresses together, it’s important that you take into consideration the type of mattress you have. If you have an innerspring mattress with a box spring, then there are certain things you need to do differently than if you just had two thin foam layers. Here are some tips for keeping your split king mattress together:

  • Use mattress protector sheets. These are specifically designed to keep two layers of mattresses together and prevent shifting.
  • Use zip ties or straps to hold the two pieces of the mattress together. This will help keep them in place as you sleep and move around during the night.
  • Add a middle support beam between your box spring and mattress if possible. This will help stabilize the mattress and keep it together even better.
  • Replace your box spring with a platform bed frame if you don’t already have one. This will provide more stability for your mattress and help keep it from shifting when you move around at night.
  • Place an extra layer of padding between the two parts of the split king mattress. This will help keep them close together and make it easier to move around in bed.
Use Mattress Protector Sheets


Split king mattresses are incredibly unique and comfortable for those that want to keep each side independent from the other. They offer many luxurious features, including adjustable bases, different types of foam layers, and temperature regulation. However, it is important to understand how to keep split king mattresses together because they can be less reliable than a single mattress.

To ensure you get the most out of your split king mattress, invest in a bed rail or wedge kit which can securely hold two twin mattresses together as one. Additionally, if your mattress senses movement, use the anti-slip mat technique to prevent pesky slips and slides throughout the night.

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Jennifer Branett

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