There are two options if you share a bed with someone who wants a much firmer or softer mattress than you (assuming you don’t want to split up or sleep in separate rooms).
One option is to buy two long single mattresses (available from Mattress Online) which are also called European single mattresses (available from Mattress Next Day) They usually measure 90cm wide and 200cm long, so if you put two side by side they’ll fit nicely on a standard super king size bed frame (180cm x 200cm).
The other option is a split tension mattress, which is also known as a dual tension mattress or a dual firmness mattress in the UK.
There aren’t all that many split tension mattresses on the UK market and they tend to be quite expensive, but we’ve picked out five split tension and dual tension mattresses which are worth considering.
Prices mentioned are for the king size version and are correct at the time of writing.
1. Flaxby Master’s Guild 4450 Pillow Top Mattress – king or super king or emperor – £1699/£1999/£2399
You might not have heard of Flaxby mattresses but they’ve got an impressive pedigree.
They are made by a UK company called Harrison Spinks, which was named as the manufacturer of the year at the main bed industry awards in 2015 and 2018. The same company also makes a lot of mattresses for John Lewis & Partners, so you know they’re at the posh end of the market.
For your money, you get a traditionally made mattress which uses pocket springs. For anyone who doesn’t speak mattress jargon, that just means that it is made using good quality springs rather than ‘open coil’ springs which are much cheaper and grottier.
There are other things to include in the ‘pros’ column for this mattress. It is hand tufted and has hand side stitching, which are two signs of quality and should mean it won’t fall to pieces and lose its shape.
Returns, sizes and warranty
In the ‘cons’ column for this mattress is the fact that it’s single sided and so can’t be flipped over. That means that you rotate it round to help stop sagging over time (a problem we all face with age). Another downside is the warranty, which is not especially generous at five years.
The split tension version of the Flaxby Master’s Guild is available as a king size split tension mattress, a super king size split tension mattress or even an emperor split tension (that is even larger than a super king). It is medium tension on one side and firm on the other.
It is sold by Dreams which has a 100 Night Comfort Guarantee. The Dreams return policy isn’t quite as simple as some. You have to use a mattress protector and can only return it between the 30th and 100th day and if it’s ‘in perfect condition’. You also can’t get a refund, they just offer an exchange. You’ll pay £65 to have it collected and if your replacement mattress is cheaper then they give you Dreams vouchers, so I guess you could buy some pillows or similar. Of course, you pay the extra if you swap for a more expensive one.
2. Dormeo S Plus Memory Foam Split Tension Mattress – double, king or super king – £649/£799
Dormeo’s split tension mattresses are certainly innovative.
Both sides of the mattress have a firmer and a softer side so you can mix and match until you find the perfect combination.
The Dormeo S Plus memory foam mattress is made from various types of foam, rather than using pocket springs, which is what most of us are used to. However, there’s a lot to be said for foam mattresses and this one actually uses some special spring-shaped foam, which it reckons offers the best of both.
Some people find memory foam makes them feel a bit warm, but Dormeo claim their design is much more breathable. Fans of memory foam like the way that it offers consistent support all over.
This mattress is also unusual because you can buy this dual tension mattress in double, king size and super king size. Most split firmness mattresses just come in the larger sizes.
It comes with a 60 night ‘comfort trial’ so you can send it back if you don’t like it. There’s also a 15 year warranty which is longer than most mattress brands. Make sure you read the Terms and Conditions with both of those things though.
3. Harrison Spinks Thornton British Wool Split Tension Mattress – double, king, super king or emperor – £839 to £1469
This is another dual tension mattress made by the same company as Flaxby – but we think it’s terrific value. One side is firm and the other is medium.
The good news is that you get lots of lovely natural fillings, including wool and cotton that are naturally good at regulating temperature. It also have something called hand side stitching, which is a way of stopping the edge of a mattress from being too wobbly.
There are other advantages too, notably that you can get in four sizes including double. I guess most people want a larger bed if they are getting a dual tension model but a double option may be all you have space for.
One side is
So, what’s the bad news?
There are a couple of things I’m unsure about with the Harrison Spinks Thornton British Wool Split Tension Mattress.
Firstly, the spring count raised my eyebrows. The blurb boasts of 5750 springs but it then explains that this is 750 standard sized pocket springs and 5000 mini springs. My personal preference is 1000-2000 full size pocket springs for ideal support. The mini springs help with comfort but it’s the larger springs that make the most difference. Lighter people will be perfectly fine, but heavier people might want to upgrade to one of their more expensive split tension mattresses.
The second query is that it is single sided. Again, this isn’t my preference as a flipped mattress tends to be less prone to drips (assuming you remember to flip it over and can actually lift it).
Overall though, it’s a great value dual tension mattress.
4. Flaxby Masters Guild 16150 Pocket Sprung Dual Tension Mattress – king or super king or emperor – £2999/£3799/£4499
What’s this? Another Flaxby mattress?
Yes indeed, dear reader. And it isn’t cheap!
This Flaxby mattress is another that lets you have one side medium tension and the other side firm, but it has a couple of upgrades from the All Seasons model featured earlier (see #1). You can choose whether it has a zip down the middle of it’s made as one mattress.
Most significantly, it is double sided so you can flip it over to help extend its life. Of course, you’ll need to be pretty strong to turn over a super king size mattress but perhaps you could keep a forklift truck in the corner of your bedroom.
It also has a load of posh natural materials inside including ‘British wool and mohair, with the addition of luxurious cashmere and silk’. The general idea is that these are naturally breathable.
The 16150 number refers to the number of springs. Let’s be clear. This is an absurd number of springs.
It’s tempting to get a bit obsessed with the spring count on mattresses and this mattress will offer plenty of support. However, it’s worth realising that you can only fit about 2000 full size pocket springs onto one layer of a mattress. The numbers are bumped up with six layers of smaller springs, which add some comfort.
The main disappointment I have with this mattress is that it only comes with a five year warranty. For a four figure price tag I would expect a 10 year warranty and for it to arrive by horse and carriage.
5. Hyde & Sleep Memory Foam Split Firmness Mattress – king or super king – £999 – £1299
Hyde & Sleep have a few different split firmness mattresses including the Ruby (half firm, half very firm) and the Citrine (half medium, half firm) and the Topaz (half medium and half firm).
Unlike the others on this guide to dual tension mattresses, the Hyde & Sleep Topaz models is a ‘hybrid’. That means that it uses a combination of pocket springs and memory foam. Pocket springs offer that familiar bouncy feel that you get from a mattress whilst memory foam is good for spreading out weight evenly.
Meanwhile, the Ruby and the Citrine models are both memory foam mattresses. Personally, I like memory foam mattresses but some people find that they make them feel a little warm.
Each model comes with a ‘zoned’ design. This is a piece of mattress jargon you will often see in product descriptions. The idea is that a mattress offers differing levels of support depending on which part of your body is like to be sleeping on it. Most of your weight is around your hips (no offence) so zoned mattresses tend to be firmer around this area than they are around your shoulders and feet.
You get a five year guarantee and a 100 Night ‘Sleep Guarantee’. Neither of those are remarkable for a mattress of this price, but it’s not too bad. They Hyde & Sleep is owned by Dreams, although it was previously run separately.
As mentioned earlier, the Dreams 100 night ‘Sleep Guarantee’ is more restrictive and complicated than some mattress trial periods. You have to keep it in perfect condition, pay for it to be returned and even then you only get to swap it for another mattress. If it costs less you end up with vouchers to spend. That’s somewhat more complex than mattress brands like Nectar Sleep and Simba Sleep, which pay for the return and give you a refund.