by We use our mattresses for a lot of activities. We sleep on them, our kids jump on them, we temporarily store clothes or luggage on them, and many times we use them as seats to put on shoes and get ready for work, to comfort a friend or partner, or for many other reasons. In this article we discuss what to do if a mattress edge collapses so that it can’t be used as a seat that easily.
If a mattress edge collapses, there are very few solutions to bolster the edge. To prevent edge collapse, regularly rotate the mattress and even out the wear and tear. To buy a new mattress with edge support, look for mattresses built with foam box encasements, butterfly side supports, or a steel perimeter frame.
The best 2023 mattress we recommend in that case
A mattress with a collapsed edge can affect the quality of your sleep without you even realizing it. This occurs when the side or edge support of the mattress begins to collapse. Usually it doesn’t happen immediately and instead it degrades slowly over time as the bed is used. Read this article from Sealy that explains how proper edge support should be incorporated along the entire perimeter of the mattress, so that the edge structure will stay firm for the lifetime of the mattress.
What is Edge Support?
Manufacturers add edge support to their mattresses in a variety of ways. Some add butterfly side supports, steel perimeter frames, foam box encasements, stronger springs, or firmer foam. Think of edge support as a type of load-bearing wall to your mattress.
Edge support is extra support added to the sides of the bed so that it can withstand more pressure in those areas. Every time we lie down or sit on the bed, the edges are subjected to greater direct pressure than the middle of the mattress. Edge support improves the integrity and durability of the entire mattress.
Good edge support prevents the mattress from sinking when you lie or sit on the edge of the bed. It also prevents slipping and falling off the bed while you are sleeping. It can assist in preventing the sensation of sliding off the bed which may occur because the mattress feels unstable— and which can cause us to tense up our muscles unconsciously to keep from falling off.
Why Does a Mattress Edge Collapse?
The edge of a mattress often takes more direct and focused pressure than the middle areas of the mattress, depending on the user’s habits, such as sitting or sleeping on the edge. The edge begins to collapse when it has been subjected—over time—to more force than it was designed to withstand. Generally, you know that the edges of the mattress have begun to collapse and sag when you sit on the edge of your bed and you start to notice a slope to the edge. Or you begin to slide off the edge of the bed.
Reasons that a mattress edge can collapse include poor construction, a sleeper that is heavier than the weight limit of the mattress, more wear and tear on one edge of the mattress due to sleeper habits, or regular sitting on the edge of the mattress.
All of these factors can work together to contribute to mattress edge collapse, but let’s look at each, one by one.
Reason 1. The Mattress May Not Have Good Edge Support
The mattress plays the most important role in edge collapse. The construction of the mattress will determine whether edge collapse is likely to happen or not. There are many mattresses that, due to their thickness, materials, and construction, cannot withstand great pressure. In many mattresses, the construction of the edges has no reinforcement, so that the mattress can lose its shape and rigidity quickly on the sides. In that case, edge collapse can happen easily and quickly.
The same thing can happen to the center of the bed which can begin to sag over time. You can check that by using a spirit level, board, or long ruler on the bed and see what is below the level. Sagging in the middle of the bed is easier to minimize with inexpensive products like a bunkie board or a piece of plywood that can be easily slipped under the mattress to provide extra support. Read our bunkie board alternatives article to discover other ways to add support beneath a mattress.
Unfortunately, edge collapse is not so easy to counteract. It really begins with the original quality of the mattress. High-quality products anticipate the problem of edge collapse and they are constructed to prevent it. Quality mattresses will generally advertise this prominently as a feature, so look for it when buying a new mattress. This Sleep Innovations mattress from Amazon has edge support listed as one of its features.
Low-quality foam mattresses are prone to edge collapse as the foam softens up over time, and the edges are made of the same foam without any additional support added. Spring coil mattresses may also not have sufficient coils that are strong enough on the edges of the mattress.
The construction of the bed support, the mattress support, and the frame, all play a significant role in preventing edge collapse. For example, if the bed that supports the mattress is not well-constructed, it can affect the integrity of the mattress’s edge support. If the mattress is wider than the bed or if the surface under the mattress is not flat and firm, the edge of the mattress won’t be properly supported. Read our article about mattress foundations vs bed frames to help decide which type of bed foundation will best fit your needs.
Reason 2. The Sleeper’s Weight May Add Pressure to the Edge
Another factor in edge collapse can be the mattress user. When the bodyweight of the sleeper is more than the mattress is designed to handle, the edge of the mattress can break down more quickly. The same thing can happen even when the sleeper is a lighter weight if they are particularly rough on the bed on a regular basis, such as jumping on it.
Whether it is springs, memory foam, or another type of mattress, regularly applying excessive weight or force can damage the mattress. Keep in mind that the average person sleeps approximately eight hours a day. This means that the bed and the mattress are already exposed to constant use and direct pressure. If the person is a heavier weight then this pressure is intensified. Read our article on how to choose a mattress topper for a heavy person if you need to improve the sleep surface for someone who weighs more.
Reason 3. Sleeping on the Edge of the Mattress
Most people have a favorite side of the mattress to sleep on. Likewise, many couples have a habit of curling up together and sleeping on one side of the bed. This produces an uneven pressure distribution for the mattress. Eventually, this can lead to bed damage. Foam mattresses can lose their ability to return to their original shape when too much pressure is applied over a long period. If the mattress has coils then prolonged stress can also wear out the springs.
One easy way to extend the life of the mattress and its edge support is to regularly rotate the mattress. This distributes the wear and tear more evenly across the entire mattress. This is a practice that everyone should adopt—even if they don’t sleep only on one side. This Zinus mattress from Amazon has pocket coils and Viscolatex foam to ensure it has a stable structure that can withstand daily use.
Reason 4. Sharing the Bed With Children or a Large Pet
Many people share their bed with a pet. Sometimes these are dogs that can be quite large and heavy. Owners rarely resist their charm, so they let them sleep with them in bed. But, this can cause the bed to collapse in the middle or on the sides and is another cause of edge collapse. Dogs often climb on the side and cause excessive pressure on the edges.
Similar deterioration of the mattress in the middle or sides can happen if children regularly jump on the bed, which weakens the construction. Children tend to climb and clamber over the edge of the bed, which is an added burden on the edge construction. If you have young children who often climb into bed with you then consider buying a step stool like this one from Amazon and teaching them to only access the bed via these steps, this will not only preserve the edge of your mattress but is also safer for the child as it lessens the chance of falling off the bed. You can also train your dogs to use the steps.
Reason 5. Sitting on the Edge of the Bed
Many people sit on the edge of the bed every morning when they get up, and sit on the edge while getting dressed and tying their shoes. Sitting on the edge of the bed places concentrated stress directly on the edge of the mattress. If the mattress is not constructed to withstand this extra pressure over time, this will cause a deterioration of the edge of the mattress.
If you spend a lot of time sitting on the edge of your bed, it is important to consider the quality of edge support in any mattress that you buy. Alternatively, consider buying a bench or ottoman which can be placed at the foot of the bed, where you can sit when getting ready in the morning. This Nost and Host ottoman bench from Amazon provides extra seating for when you’re putting on your shoes, and can double as storage for any extra bedding items too.
Is it Normal For a New Mattress Edge to Sag?
Not all sagging is bad. Here a mattress topper placed over a mattress looks like it’s sagging but this is totally normal. Image from Terrycrale.With every mattress, some edge collapses will develop over time, but, in the beginning, it should never happen. When you are buying a new mattress, look at the mattress’ edge support and consider how much your typical use of your mattress is likely to add stress to the edges of the mattress. Look for a mattress that has good edge support built in.
It isn’t normal for a new mattress edge to sag. A new mattress should be resistant, firm, and durable. Even in shops where people try out mattresses by sitting on the edge, the edge of a new mattress should not collapse. Such collapse should be an immediate warning sign because they indicate a factory flaw or a poorly constructed mattress.
Don’t interpret every little dip in the edge as a serious problem. When you check the mattress, if the depression is up to two inches, it does not indicate a problem. A little indentation needs to be allowed to sink in and cushion a sleeping body. Normal depression in a mattress when someone lays on it isn’t an indication of inferior materials in the mattress’ construction. Materials such as memory foam naturally adapt and compress. Read our article on memory foam vs. smart grid foam to understand how these materials compress to provide support when sleeping.
More importantly, you don’t want a mattress where the sides do not compress at all. If the sides don’t compress when the rest of the mattress does, you will have a whole other set of problems. The hard sides become a sort of hard and uncomfortable wall around the softer mattress.
Only some mattresses, like the Lucid hybrid mattress, offer dedicated edge support, so it is important to look for it as a feature. Image Source: Amazon.Edge Support To Look For In a New Mattress
The type of edge support needed in a mattress will be determined by the type of mattress—a mattress with coils will need different edge support compared to a mattress made entirely of Latex for example.
To provide edge support for a mattress, manufacturers may add a foam box encasement, butterfly side supports, or steel perimeter frames.
In this article from John Ryan, makers of bespoke handmade mattresses in the UK, the manufacturer describes the reasons for having good edge support in a mattress and the kinds of edge supports they use, such as rows of firmer springs around the edges or butterfly springs.
Foam Box Encasements Add Edge Support to Foam Core Mattresses
A solid foam edge is the only way to add extra support to the edges of a foam core mattress. Sometimes manufacturers also use them as edge support in the frame around an innerspring mattress. The foam must be very high quality and firm.
However, because it can be very expensive, manufacturers sometimes use cheaper foam. When they do, the wrapper or foam frame can wear out and fall apart faster than the rest of the mattress, which makes the whole mattress useless.
If the foam box is of a high quality and is used around a tied inner-spring unit, this can dramatically reduce the lateral movement of the spring unit. Which means it controls movement and increases quality. The foam walls must be thick enough to absorb the stressors it is subjected to. This Avenco mattress from Amazon has inners pocket springs and a dual perimeter reinforced edge, for optimum structural integrity.
Butterfly Side Supports Are Metallic Spring Systems for Mattress Edge Support
Butterfly side supports is a metal construction that uses a spring system to support the sides of the bed or mattress. These are used commonly by manufacturers when the steel perimeter frames around a spring unit are too light in wire gauge to offer sufficient edge support. The manufacturer places the butterfly side supports around the edges of the spring unit to prop the sides up and welds them to the perimeter frames.
Some manufacturers will use pillars or beams of polystyrene foam in place of these butterfly supports. This is an even worse option for someone who regularly sits on the edge of the mattress, as the pillars provide much less stability than a butterfly side support and are quite uncomfortable to sit on.
Steel Perimeter Frames Are Common Edge Supports for Innerspring Mattresses
Steel perimeter frames are necessary for every mattress with internal springs to hold the springs together. They also add a higher level of support around the edge of the mattress. The frames consist of heavy loads of one-piece wire borders made of high-carbon steel that extend around the top and bottom of the spring unit. The steel boundary wires are attached to each outer spring around the perimeter of the unit, and the alloy is hardened so that the frames will last much longer than the normal life of the mattress. The frames will flex slightly as you sit on the bed so you don’t feel any discomfort from a hard edge.
How to Choose a Mattress with a Firm Edge That’s Durable
When choosing a mattress with a firm edge you need to pay attention to the basic characteristics and material of the mattress. For example, the popular Winkbed is highly rated for edge support, with customers appreciating its side panels and coil system. The eight-inch coil provides strong support for the entire bed, which minimizes sinkage around the outer edge of the mattress.
To choose a mattress with a firm edge that will not collapse, buy a thicker mattress that tends to be more expensive and have a better construction. Test the sides of the mattress to determine if the mattress it has butterfly supports, a steel perimeter, or a foam box encasement. Ask the salesperson or read reviews on sites like Amazon before making your purchase.
Poor memory foam or a poor quality coil system will usually cause problems with the mattress edge support because they won’t withstand increased or direct pressure. The type of material is not as important as the quality of that material and the design of the mattress, which is of course directly related to the price. Read our memory foam mattress shopping guide and our orthopedic mattress shopping guide for handy tips when choosing your ideal mattress. Additionally, our guide to orthopedic mattress materials and guide to orthopedic mattress sizes might also be helpful.
Examples of Mattresses with Firm Edges
| Product | Mattress Features | Edge Support Provided | Price |
| Twin Mattress, Avenco Cold Foam and Innerspring Mattress Twin | 10-inch firm mattress, with 2 cm gel memory foam, high-density support foam, innersprings, and edge banding around | “Dual perimeter edge system” using a steel perimeter frame | ~$300 |
| Lucid 12 Inch Full Latex Hybrid Mattress | 12-inch full latex hybrid mattress with plush memory foam layer and 6.5-inch, high-quality steel coils | Foam box encasement using steel coils | ~$500 |
| Sunrising Bedding 8 inch Natural Latex Twin Mattress | 8-inch hybrid firm mattress with pocket coil springs and 20 year warranty | Pocket coil spring support system (likely butterfly springs) | ~$290 |
| Avenco Store 12-inch hybrid mattress with inner-spring and gel memory foam | 5 Zone independent pocket inner-spring design with edge support | Individual pocket spring inner with high density foam encasement | ~$460 |
You may also find interest in all of the different types of beds out there and how to make them work with your room. Make sure to take a look at this article about 7 sleigh bed ideas to enhance your bedroom.