How to set up a mattress in a box: 5 dos and don'ts for getting your new bed ready

Image shows the Birch Luxe Natural mattress being unboxed and placed on a bedframe
(Image credit: Birch)

Setting up your new mattress in a box is exciting, but there are some specific steps you need to follow to ensure your new bed is as healthy as possible from the start – and that you have an easier time unboxing it. 

Take a look at our official best mattress guide and you'll see that most of our top recommendations come compressed in a box. They are cheaper and more convenient than buying in store, but the downside is that you'll have to wait for the mattress to expand before it's ready to sleep on. 

What is a mattress in a box?

Beds-in-a-box are compressed, wrapped in reinforced plastic and neatly packaged into a box before being shipped directly to your door. They are often more convenient and cost-effective than buying in store, and come in different types including memory foam, hybrid and organic. 

Leading sleep brands such as DreamCloud and Nectar box their beds with full instructions to hep you learn how to set up a mattress in a box quickly, but sometimes you'll need further advice. That's were our mattress experts come in.

While brands such as Casper and Simba say they're mattresses are ready to sleep on right away, other brands such as Purple and Emma recommend waiting over 24 hours. There's also mattress off-gassing - the chemical smell of a new bed. Some mattresses are odourless, while some need extra time to let the scent fade. 

Luckily, we've rounded up 5 expert-approved tips to show how to set up your bed in a box and avoid common mistakes. So, if you're shopping for the best mattress in a box for you in the upcoming Presidents' Day mattress sales, follow these tips and you'll be able to set it up in no time.

How to set up a mattress in a box: 5 dos and don'ts

1. Do ask friends or family for help 

While mattress in a box are more compact and easier to move than flat mattresses, it doesn't mean their light or completely easy to move. Boxed beds, especially hybrids that combine foam and springs, can be super heavy and difficult to unbox and get onto a bed frame by yourself. Remember, a US queen size mattress weighs up to 160 lbs, while a US king size can weigh up to 180 pounds. A UK double, on the other hand weighs about 105 lbs and a UK king weighs around 125 lbs. 

To help you carry these hefty beds, certified sleep coach Claire Davies suggest enlisting the help of family and friends.  “My top tip is to get someone to help you unbox your mattress," the sleep expert says. "These beds can be heavy in the larger sizes! Place the box on your bed frame. Next, you hold the box at one end, while the person helping you pulls the rolled mattress out of the other end. It’s easier than trying to drag the rolled mattress out of the box by yourself.” 

Image shows the Emma Original mattress tightly rolled and covered in tough plastic

(Image credit: Future)

2. Don’t let the mattress expand on the floor 

A lot of mattress brands, such as Nectar, advise you to put the mattress on a bed base ore bed frame as soon as it's unboxed. Davies explains that this is so the materials are fully protected during expansion.

“If your mattress comes with a specific step-by-step guide to setting up, read it first," she warns. "For example, hybrid mattresses will need to be placed on your bed frame in a specific way so that the top layers are not on the bottom during the expanding process as this could damage your new bed.” 

3. Do use the provided cutting tools

When your mattress arrives rolled and wrapped up in plastic, you may get a little too eager and reach for the first sharp object to cut your bed free from it's packaging. However, a lot of mattresses come with their own cutting tools, so use them. 

Don't tear into the protective plastic with a pair of scissors or knives, as this could damage the mattress cover. A damaged mattress cover can void the warranty, make your mattress uncomfortable, and (depending on the bed) expose you to harmful substances such as fiberglass. 

4. Don’t sleep on it straight away

The time it takes for mattress to expand depends on the brand, material, room temperature, and how long it's been stuck in the box. Always read the manufacturers' guidance and check out our guide to sleeping on an expanding mattress, which lists the expanding timeframe of major sleep brands such as Simba, Purple and Zinus. 

Cocoon by Sealy, for example, recommend waiting up to 24 hours before sleeping on their mattresses. Why? "Applying additional pressure will not allow the mattress to fully expand," sleep experts at Cocoon by Sealy told us. 

Image shows the Eve Premium Hybrid unboxed and placed on a white bed frame ready for testing

There was hardly any off-gassing when we unboxed this Eve mattress (Image credit: Future)

5. Do open a window during the unboxing

A rolled-up bed may be convenient for shipping and delivery, but it does come with a side effect: off-gassing. Mattress off-gassing is the chemical smell that emanates from a freshly unboxed mattress. It's not dangerous, but it can be annoying. (We leave our windows closed when unboxing a new bed for testing as it's essential for us to get a clear indication of how much off-gassing occurs.)

“I’ve unboxed countless mattresses for testing, and the mistake I made in the beginning was not opening the window first," says Davies. "The off-gassing smell is particularly potent with memory foam and can linger well into the next day, so get some fresh air flowing before setting up your mattress.” 

How to set up a Nectar mattress in a box

Nectar mattresses come with a cutter to help pierce the box and open the plastic packaging. They recommend enlisting someone to help you, as it's a 2-person job. One you've opened your new Nectar mattress, place it straight away and wait 5 hours for it to expand (and to sleep on it) and up to 48 hours to expand fully.

The Nectar Memory Foam Mattress: $699 $359 at Nectar Sleep

The Nectar Memory Foam Mattress: from $699 $359 at Nectar Sleep
The Nectar Memory Foam is a great choice for people who sleep on their back or stomach, and will keep hot sleepers cool thanks to its great temperature regulation. Currently, Nectar is holding a 40% off early access Presidents' Day sale, which knocks a queen size down to $659 with this month's Nectar mattress deals.  

How to set up a DreamCloud mattress in a box

According to their website, setting up a DreamCloud mattress shouldn't be too difficult. They recommend moving the box to the desired room, sliding out of the box, unrolling it onto the bed base, and waiting 24 hours to sleep on it. 

The DreamCloud Hybrid Mattress: $839$419 at DreamCloud Sleep

The DreamCloud Hybrid Mattress: from $839 $419 at DreamCloud Sleep
The DreamCloud Hybrid has 4 layers of contouring foam and a tier of individually wrapped coils for a breathable supportive sleep, making it ideal for all sleep positions. Currently, there's a 50% off winter flash sale, meaning you can get a queen size hybrid for just $665 in the new DreamCloud mattress sale.

How to set up a Purple mattress in a box

Kristen Olson-Turner, Sr. Director of Product Merchandising at Purple, recently told Tom's Guide that you should wait for a Purple mattress to fully expand before sleeping on it. "For Purple mattresses, we would like to give the mattress six hours to expand before sleeping on it," she said. 

The Purple Mattress$999 $799 at Purple

The Purple Mattress: from $999 $799 at Purple
The signature, best-selling bed of sleep brand Purple, the Purple Mattress has excellent temperature control for hot sleepers, good motion isolation for restless couples, and a cushioning comfort for all sleep styles. Currently you can get $400 of a queen size mattress, reducing it to $1,099 in the Purple mattress sale.

How to set up a Casper mattress in a box

While Casper says their mattresses are ready for sleep within minutes, they still recommend leaving it for two hours so it reaches its maximum volume and comfort levels. 

The Casper Original $895$760.75 at Casper

The Casper Original: from $895 $760.75 at Casper
The Casper Mattress's all-foam design makes it ideal for side sleepers, and has phenomenal motion isolation for couples. Currently, you can get 15% off this mattress, dropping a queen size down to $1,100.75 (was $1,295). For more discounts, see our Casper mattress deals and sales guide.

How to set up a Helix mattress in a box

Helix recommends setting your new mattress on your foundation while it's still in its plastic packaging. When you remove it from the plastic, make sure the Helix logo is upright at the foot of the bed then give it two hours to expand 

The Helix Midnight:$936.30 $749 at Helix Sleep

The Helix Midnight: from $936.30 $749 at Helix Sleep
With its medium feel and soothing pressure relief, The Helix Midnight is a side sleeper's dream bed. It also has great motion isolation for couples, and good temperature regulation for hot sleepers. Helix are hosting a n New Year sale (ending in February), which means you can get 20% off all sizes, including a queen size for just $1,099, in the new Helix mattress sale.

How to set up a Birch mattress in a box

Birch Living recommends putting your unboxed mattress on your bed frame, then pulling on the plastic tab to unroll. Their mattresses don't come with a complementary cutter, so use scissors to cut the final layer of plastic. Leave your mattress one to two hours to fully expand, and then it's ready to sleep on.  

Birch Natural Mattress $1,498.80 $1,199 at Birch Living

Birch Natural Mattress: from $1,498.80 $1,199 at Birch Living  
Back and stomach sleepers will get along just fine with this organic mattress thanks to its firmer feel for proper spine alignment. The temperature regulation is also great, as the breathable latex and air-flowing springs create a cooler night's sleep. Currently, you can get 20% off the Birch Natural, with a queen size reduced from $2,123.80 down to $1,699.

Should you set up a boxed mattress as soon as it’s delivered?

While mattress brand differ on how long a mattress should be left to expand before sleeping on it, they seem to agree on one thing: for  your mattress to give its best performance, unpack it as soon as it arrives. 

 “Ideally, you should open your mattress in a box as soon as it is delivered to avoid the materials (and mattress shape) staying compressed for too long," recommends Davies. "The sooner you use it, the more of your mattress trial you’ll get to use too.”

Frances Daniels
Sleep Staff Writer

Frances Daniels recently joined the Tom's Guide team as Sleep Staff Writer, and her role includes covering all sleep and mattress news, in addition to mattress reviews and buyer's guides. Frances is a PPA-accredited journalist and is hugely interested in the relationship between good sleep and overall health. When not writing about sleep and mattresses for Tom's Guide, Frances enjoys writing about women's issues, health and wellbeing, the environment, and her native Wales.