Based on a spend of £589
3 interest-free payments of £196.33
The first payment is made at point of purchase, with the remaining 2 payments scheduled automatically every 30 days. No fees
18+, T&C apply, Credit subject to status.
For more information about Klarna click here.
Simply apply during checkout.
* If you are retired and receive a pension or registered disabled and unable to work, our finance provider may ask for proof of sufficient income. Credit is subject to status. Terms and conditions apply.
What do I need to apply online?
For more finance FAQs please click here.
The Derwent is a medium firm adjustable bed mattress from Adjust-A-Bed, designed and handmade in Great Britain and built specifically for use with an adjustable base. It's constructed around 1000 individually pocketed springs paired with a breathable Air-Lite Comfort Foam layer, with foam-encapsulated edges for stability and a traditional tufted finish. The result is a supportive, medium firm mattress that suits sleepers who change position through the night, with springs that respond independently for pressure relief and reduced partner disturbance.
A 1000-pocket-sprung adjustable bed mattress with a breathable Air-Lite Comfort Foam layer, best suited to sleepers who want medium firm, adaptable support, effective pressure relief, and consistent support through every base position.
Medium Firm Feel - 4/6: A supportive feel with added stability. Ideal for people who change sleeping position during the night and need a balance of comfort and support.
Best for
Not ideal for
1000 Pocket Spring System
What it is: 1000 individually wrapped springs. The upper part of each spring shapes to the body's contours while the lower part absorbs changes in weight distribution.
How it helps you sleep: Springs work independently to avoid rolling together, providing tailored support with minimal motion transfer between sleeping partners.
Air-Lite Comfort Foam
What it is: A breathable comfort foam layer that conforms to the body's contours.
How it helps you sleep: Provides personalised support and pressure relief at the hips, shoulders, and lower back, helping reduce the likelihood of waking up with aches and pains.
Foam Encapsulated Edges
What it is: A high-density foam strip placed inside the edge of the mattress springs.
How it helps you sleep: Prevents the mattress sagging at the edge, giving a more supportive sleeping area and more usable edge-to-edge space.
Tufted Finish
What it is: A traditional upholstery method where fillings are secured with tufts running from the top of the mattress to the bottom.
How it helps you sleep: Keeps loose fillings secured in place for a consistent, supportive finish over time.
| FEATURE | DETAIL |
|---|---|
| Brand | Adjust-A-Bed |
| Category | Mattress |
| Model | Derwent |
| Firmness | Medium Firm (4/6) |
| Mattress Type | Pocket spring and comfort foam |
| Foam Free | No |
| Spring System | 1000 Pocket Springs (no proprietary system name given by manufacturer) |
| Spring Count | 1000 |
| Comfort Layers | Air-Lite Comfort Foam |
| Cover | Smooth to touch tufted cover |
| Mattress Finish | Tufted |
| Mattress Depth | 25cm (9.8'') |
| Edge Support | Yes - foam-encapsulated edges |
| Temperature Regulation | Yes - moisture-wicking properties help air circulate through the mattress |
| Hypoallergenic | The Air-Lite Comfort Foam layer is described as inherently resistant to dust mites and allergens. |
| Care Instructions | No need to turn - rotate head to toe regularly to extend lifespan |
| Compatible Bed Bases | Adjustable bases only |
| Single or Double Sided | Single sided - do not flip |
| Country of Manufacture | Great Britain |
| Maximum Weight Per Side | 25 stone (158kg) per side |
| Guarantee | 5 years |
| Ideal For | Combination sleepers, back sleepers, front sleepers, couples |
| Fire resistance | All mattresses are BS7177:2008 compliant |
| SIZE | WIDTH x LENGTH x DEPTH | CONFIGURATION |
|---|---|---|
| Adjustable Small Single | 75cm (2ft6) x 200cm (6ft6) x 25cm (9.8'') | Single piece |
| Adjustable Single | 90cm (3ft) x 200cm (6ft6) x 25cm (9.8'') | Single piece |
| Adjustable Small Double | 120cm (4ft) x 200cm (6ft6) x 25cm (9.8'') | Single piece |
| Adjustable Double | 135cm (4ft6) x 200cm (6ft6) x 25cm (9.8'') | Single piece |
| Adjustable King Size | 2 x 75cm (2ft6) x 200cm (6ft6) x 25cm (9.8'') | Split design - 2 mattresses |
| Adjustable Super King Size | 2 x 90cm (3ft) x 200cm (6ft6) x 25cm (9.8'') | Split design - 2 mattresses |
Vs firmer adjustable mattresses: The Derwent's pocket springs and Air-Lite Comfort Foam give noticeably more cushioning at the shoulders and hips than a firmer, foam-only option. If you sleep on your side, change position through the night, or share a bed, this is likely the better choice. A firmer adjustable mattress suits back or front sleepers, heavier sleepers, or those with specific orthopaedic support needs who prefer minimal sink.
Vs softer adjustable mattresses: The Derwent has more structural support underneath its comfort layers thanks to the 1000 pocket springs and foam-encapsulated edges. A softer mattress can feel more immediately plush, but may not maintain support as consistently for combination sleepers or heavier body weights.
Vs buying with a base: This mattress is also available together with a matching Adjust-A-Bed adjustable base - useful if you are buying your first adjustable bed and want guaranteed compatibility between base and mattress. If you already have a compatible adjustable base and simply want to upgrade the mattress, this mattress-only option lets you do that without replacing the whole bed. The paired bed and base listing can be found here.
The Derwent is backed by Adjust-A-Bed's 5-year manufacturer's guarantee against defects in materials and workmanship. Given the pocket spring and foam-encapsulated construction, this is a mattress built for consistent, supportive comfort over time, and the guarantee reflects that.
The Derwent delivers medium firm, adaptable support with 1000 pocket springs and a breathable comfort foam layer, designed and handmade in Great Britain and backed by a 5-year guarantee. If you change position through the night, share a bed, or simply want balanced comfort and support that holds its shape through every adjustable position, this is one to consider.
Not sure which Adjust-A-Bed mattress is right for you? See our Adjustable Bed Buying Guide for guidance on tension, base compatibility, and comfort levels.
| WHAT'S INCLUDED? | |
|---|---|
| Mattress | Yes |
| Base | No |
| Headboard | No |
PLEASE NOTE:
All measurements are approximate and are subject to a tolerance of + or - 2cm.
Image is for illustration purposes only.
Pillows, cushions, throws and bed dressings not included.
Is this mattress suitable for an adjustable bed?
Yes this mattress is designed to be used on an adjustable bed.
What is the depth of this mattress?
This mattress is 25cm deep.
How does an adjustable bed mattress differ from a regular mattress?
An adjustable mattress is designed to flex and contour to different positions when used with an adjustable frame which allows for customised comfort and support. A regular mattress is designed to lay flat and cannot be bent.
Can I sleep on this mattress straight away?
Yes, you can sleep on your mattress straight away.
Will this mattress make me hot?
This product has properties that help wick away moisture allowing air to circulate through the mattress. Therefore in most situations this mattress won't cause excessive heat.
Made to measure mattresses and divan bases are available – please call 01928 242829.
Our experienced delivery team can take away your old bed or mattress when delivering your new one. Please ensure you have dismantled your old bed prior to delivery.
Simply add this service to your order at checkout.
What products will you remove?
We will remove mattresses, divan beds and bed frames (subject to all beds being dismantled first). Add this convenient service to your order at checkout.
Do I need to dismantle my old bed before collection?
Yes, your old bed must be fully dismantled.
Can I add Removal and Recycle on after placing my order?
You can either add it to your order on the basket page and pay at checkout, or if you would like to add it after you have checked out, simply contact us on 01928 242829 before your order is due for delivery.
Do you recycle the beds and mattresses you collect?
When we remove your old bed or mattress, we ensure that it is disposed of in an environmentally responsible way. All products are sent to The Furniture Recycling Company, the UK's largest and most trusted furniture recyclers.
Our skilled drivers deliver throughout the UK and will deliver straight to your home. Free doorstep delivery is available on many products and you can also choose delivery to room of choice for an additional fee.
How much is delivery?
We offer free delivery to most of the mainland UK for orders over £100; there are applicable charges for deliveries to the highlands or far out UK, which can be found by putting your postcode into the delivery section on the product page. For orders under £100, there is a £10 charge.
How long does delivery take?
Once you select the required product, an approximate delivery time will be quoted on the product page before adding the item to your basket. During checkout, you will either be given the option to select your date, or we will state an estimated time for delivery. Once you have placed your order, we will contact you to book a date within the timeframe quoted.
Will I be contacted beforehand to arrange a delivery slot?
Once you have placed an order, our delivery team will contact you directly to arrange a suitable delivery slot, either via email, call, or text message.
Can I choose my delivery day?
If the product is available for next-day delivery, you can select a date at checkout. For all other products, you will be presented with an estimated timeframe for delivery. After placing your order, our delivery team will contact you via e-mail, text or call to arrange a suitable delivery day/time.
Read all our Delivery FAQs
We have an easy returns policy: If you change your mind, we're happy to accept returns within 14 days of you receiving your product, as long as they are unused and unassembled. However, for hygiene reasons, we can't take back products that have been slept on, unless there's a fault.
Custom-made products can only be returned if they are faulty.
Please take a look at our Terms & Conditions.
Can I return a mattress I've slept on?
Normally, mattresses can only be returned if they're unused within 14 days. But if your mattress has a trial period, please refer to the mattress trial information page for further details.
How long do I have to return an item I've purchased online?
You have 14 days to return an item if bought online, subject to the item not being used or assembled. Please note, if you wish to inspect a mattress, please ensure the protective outer plastic packaging is not removed, as this may affect your right to return due to health and hygiene reasons. Any product that is made to order/customised cannot be returned unless faulty.
Do I have to pay for the return?
To return your product, you can either arrange the return yourself, or we can happily arrange it on your behalf for a charge, which will be deducted from your refund. The collection charge covers the expenses involved in picking up the item from your location and safely bringing it back to our warehouse. For bedding items, the amount is £20, and for large/bulky items, charges start from £95 (depending on the product/postcode).
Can I return a part or fully assembled item?
Unfortunately, once an item is assembled, whether partially or fully, we can't accept returns unless the item is faulty.
Read all our Returns FAQs
Our skilled drivers deliver throughout the UK and will deliver straight to your home. Free doorstep delivery is available on many products and you can also choose delivery to room of choice for an additional fee.
How much is delivery?
We offer free delivery to most of the mainland UK for orders over £100; there are applicable charges for deliveries to the highlands or far out UK, which can be found by putting your postcode into the delivery section on the product page. For orders under £100, there is a £10 charge.
How long does delivery take?
Once you select the required product, an approximate delivery time will be quoted on the product page before adding the item to your basket. During checkout, you will either be given the option to select your date, or we will state an estimated time for delivery. Once you have placed your order, we will contact you to book a date within the timeframe quoted.
Will I be contacted beforehand to arrange a delivery slot?
Once you have placed an order, our delivery team will contact you directly to arrange a suitable delivery slot, either via email, call, or text message.
Can I choose my delivery day?
If the product is available for next-day delivery, you can select a date at checkout. For all other products, you will be presented with an estimated timeframe for delivery. After placing your order, our delivery team will contact you via e-mail, text or call to arrange a suitable delivery day/time.
Read all our Delivery FAQs
We have an easy returns policy: If you change your mind, we're happy to accept returns within 14 days of you receiving your product, as long as they are unused and unassembled. However, for hygiene reasons, we can't take back products that have been slept on, unless there's a fault.
Custom-made products can only be returned if they are faulty.
Please take a look at our Terms & Conditions.
Can I return a mattress I've slept on?
Normally, mattresses can only be returned if they're unused within 14 days. But if your mattress has a trial period, please refer to the mattress trial information page for further details.
How long do I have to return an item I've purchased online?
You have 14 days to return an item if bought online, subject to the item not being used or assembled. Please note, if you wish to inspect a mattress, please ensure the protective outer plastic packaging is not removed, as this may affect your right to return due to health and hygiene reasons. Any product that is made to order/customised cannot be returned unless faulty.
Do I have to pay for the return?
To return your product, you can either arrange the return yourself, or we can happily arrange it on your behalf for a charge, which will be deducted from your refund. The collection charge covers the expenses involved in picking up the item from your location and safely bringing it back to our warehouse. For bedding items, the amount is £20, and for large/bulky items, charges start from £95 (depending on the product/postcode).
Can I return a part or fully assembled item?
Unfortunately, once an item is assembled, whether partially or fully, we can't accept returns unless the item is faulty.
Read all our Returns FAQs
