Memory Foam Mattress Corners Not Expanding

You did all the research, carefully selected the perfect memory foam mattress, and finally got it delivered. But as you let the mattress out to decompress and do its thing, you notice the corners look a bit… deflated.

Why is that? Do you need to return it?

Mattresses need warmth, lots of room, and adequate time to fully expand after being compressed for shipping. Otherwise, any part of the mattress (corners included) may stay sunken and lumpy.

Of course, there’s always the possibility that your research wasn’t as solid as you thought, and the foam quality is subpar.

Don’t worry, though. This guide will walk you through the most likely reasons behind your mattress corners not expanding properly. We’ll also share some expert tips for handling the situation so you can get a good night’s rest as soon as possible!

5 Possible Reasons Why the Corners Aren’t Expanding

Before you start stressing, take a deep breath, and let’s figure out what’s causing those sad, squished corners.

1. You Didn’t Wait Long Enough

Typically, you should let a new memory foam mattress decompress for 24–72 hours. Its height should be roughly the same at the corners, center, and edges.

That said, not all memory foam will get to this point just as quickly.

The thing to remember is that more squished materials need more time to re-fluff. So, denser foam types like gel-infused, copper-infused, or graphite-infused memory foam may need extended recovery time compared to traditional memory foam.

What Is MEMORY FOAM? Interesting FACTS You Might Not Know // A No Bull Guide

On the other hand, hybrid mattresses that combine foam with other materials like innerspring coil can expand faster.

2. The Mattress Sat in the Box Too Long

Another prime suspect? Your mattress may have been stuck in its vacuum packing for too long.

As you know, foam compresses under sustained pressure. That’s why the manufacturer might recommend unboxing your new mattress within 72 hours of receiving it.

If it sits there much longer than that, the packaging can really squeeze on the foam, especially in those corner areas. When you finally free it, the foam material may struggle to bounce back into shape.

3. Something Is Squishing the Corners

It’s not recommended to put weight on a still-expanding mattress. That’s precisely why we advise our customers to let the foam puff out fully before sleeping on it.

The same goes for anything that could “cave” in the corner. For instance, you might have left it to decompress on the floor, and it expanded a bit until the corner hit a wall or nearby furniture.

It’s better to clear up the area to let foam “breathe” and expand without anything weighing it down.

4. Your Bedroom Is a Bit Chilly

Memory foam is made from viscoelastic materials that need warmth and time to rebound after being compressed for shipping.

Cooler temperatures = Higher risk of improper expansion (for corners and the entire mattress!)

5. Your Mattress Is Just Defective

Sadly, you could be dealing with a straight-up defective or poor-quality memory foam mattress. Despite your best efforts and waiting patiently, the corners may stay weirdly misshapen or bumpy.

This is more common with mattress brands that cut corners (no pun intended) on materials and quality control.

You see, the manufacturing process behind quality memory foam is an intricate blend of chemistry and technology. Everything from getting the chemical formulas just right to using computer-aided cutting has to be on point.

If there are slip-ups along the way, you could easily end up with compromised foam integrity.

How to Deal With Saggy Memory Foam Mattress Corners

So you’ve waited the recommended expansion time out, but those memory foam mattress corners are still saggy and misshapen. Don’t throw in the towel just yet!

There are a few tricks you can try to coax those corners out.

The key is creating an optimal environment for your mattress to fully decompress. After being rolled up tightly for shipping, the compressed foam needs some extra TLC to get that full shape and supportive feel.

Give the Corners Enough Space

First things first, make sure you aren’t hindering those corners from spreading their wings, so to speak. This means laying the mattress on a large, flat surface until the complete expansion is over.

Make sure nothing is blocking that airflow in the corners, either. Air circulation is crucial since oxygen exposure helps the memory foam regain its fluffy form.

Bonus point: The airflow will help you air out the factory mattress smell.

Crank up the Heat

Allowing your room to reach 72°F or so can work wonders for helping the foam layers loosen up.

Most folks aim for an average room temperature of 68–76°F, anyway. But if you like your house chillier, you might want to consider setting the thermostat higher just for a few days.

You could also use a space heater aimed at the corners to concentrate the warmth.

Some people suggest steaming the saggy areas with an iron. However, you should be very cautious with this approach. 

For one, we’re sure you don’t want to accidentally scorch the mattress and null the warranty.

Plus, too much moisture can lead to mold and odor issues down the road. Sure, a mattress can handle steaming, but this is assuming you’re using a steam cleaner made for foam, not a household iron.

Long story short? Warming the whole room is often a safer bet.

Gently “Massage” the Corners

This one may sound a little silly, but hear us out—giving those saggy corners a little massage can help even them out!

In fact, a similar tactic is used to speed up the expansion process for the whole mattress. But of course, rather than massage the whole thing by hand, you’d jump right up there and use your body weight (and body heat!) to work the foam for a few minutes.

Exercise Your Warranty

Just as an example, No Bull Mattress & More memory foam mattresses come with at least a 10 year warranty, so if the mattress is defective then it can be replaced by the manufacturer at no cost.

3 Golden Tips for Avoiding Expansion Issues in Future Mattress Purchases

Dealing with misshapen mattress corners is an annoying hassle, to say the least.

But by being an informed shopper from the get-go, you can reduce the chances of running into this issue with your next purchase.

1. Choose High-quality Foam

The best preventative measure for all expansion issues (not just around the corners) is to invest in a quality mattress from brands that prioritize premium construction and strict quality control measures.

Needless to mention, this will also help you get an even higher comfort level from your memory foam!

2. Ask About the Sleep Trial and Return/Exchange Process

You want to look for retailers that offer generous sleep trial periods of 100 nights or longer. Some brands may even allow an entire year! 

Just a note: the reason a lot of these companies can offer low-priced “bed in a box” mattresses and also offer 120 night sleep trials with free returns is because their margins are so high (which also means the quality of the product is very low). Legally, they cannot sell a used mattress, so your returned product is often sent to the dump or “donated”. They can do this only through high margins.

https://old.reddit.com/r/Mattress/comments/oq4rl3/avoiding_buyers_remorse_3_strategies_aka_why_try/

This buffer gives you lots of time to properly evaluate if the mattress—corners and all—is the perfect fit.

Make sure to ask about all the nitty gritty details and read the fine print. If the company sent you any complementary services/products with the order, they might deduct their price when you return the defective mattress.

You want to know all these details and be prepared!

We’d also highly recommend that you spend the trial focusing on more than just the expansion. There’s a lot more that goes into testing the compatibility of a mattress than just waiting for it to fluff up and then laying on it for a while.

3. Schedule Your Delivery Wisely

Finally, try to order your new mattress several days in advance. This way, you won’t have to rush the expansion period.

At No Bull, we try to make the processes as smooth as possible. So, you can easily schedule your delivery days ahead of time.

Final Thoughts

No one should have to sleep on a mattress with sad, lumpy corners. They compromise the support and are just a blot on the landscape.

To tackle the situation, you can give the corners a bit of time, room to expand unhindered, good air circulation, a warm environment, and a gentle knead.

And if those corners still won’t cooperate, don’t hesitate to reach out to customer service. Any decent mattress company will want you to be 100% satisfied.

That’s exactly why our team makes a habit of following up with new customers. We want everyone to get the sleep experience they had hoped for when they bought a memory foam mattress from our stores!