Detailed Specification

Please note: all imperial measurements are approximate and Mercia products are made from metric measurements.  We would recommend that the base is at least 50mm bigger in each direction.

Product Name: 10 x 20 (3.18m x 6.06m) Mercia Premium Reverse Apex Shiplap Workshop - Pressure Treated
Footprint (Depth x Width): 3.18m x 6.06m (10'5" x 19'11")
Height to Ridge: 2.48m (8'2")
Height to Eaves: 1.77m (5'10")
Walls: 12mm Shiplap Tongue and Groove
Framing: 45mm x 28mm (2" x 1")
Door: Double Doors
Door Opening (Height x Width): 1.66m x 1.10m (5'5" x 3'7")
Door Lock: Hasp and Staple
Roof Type: Reverse Apex
Roof: 12mm Tongue and Groove
Roofing Felt: Green Mineral Felt
Floor: 12mm Tongue and Groove 
Floor Joists: -
Floor Joists Direction: Front to Back
Window(s): 3 Opening Windows
Window / Wall Panels: Interchangeable
Window Glazing Material: Styrene
Windowless Option Available: N/A
Treatment: Brown Base Pressure Treatment
Portabases Available: N/A
Manufacturer's Guarantee: 15 Year Anti-Rot Guarantee
FSC Certified: Yes
Free Delivery: Yes*
Assembly Available: Optional
EAN Number: 5029442089546
Recommended Treatment: Protek Range (please click here)
Manufacturer: Mercia


This 10 x 20 colossus of a garden workshop contains enough room for a number of storage shelves, pieces of garden equipment, work benches, or supplies that can be stored outdoors. Three windows that each open make the workshop a perfect environment for working, mounted high enough on the wall to make sure there is plenty of space beneath for a work bench. The workshop’s set of double doors open wide and ensure that any bulky items can be easily accessed from the building.                                              

When it comes to increasing your available space, it is often better to be safe than sorry. If you need to be certain you will have enough storage and workshop space in your garden building, the 10 x 20 Mercia Premium Reverse Apex Shiplap Workshop is a cost effective solution with an excellent build quality you can trust to last.


The spectacular size of this 10 x 20 workshop is, without a doubt, its selling point. But the workshop’s strength and durability at this size is made possible by its solid 2 x 1 framing, as well as its shiplap tongue and groove cladding that features interlocking 12mm timber. Unlike overlap cladding used on cheaper sheds, this design has a low profile that looks sleek and matches the similar tongue and groove construction used in the roof and floor. By tightly interlocking the individual pieces of timber, an excellent level of protection from the elements is provided.

Pressure Treatment - This shed comes pressure treated in an attractive, brown colour. Pressure treated timber has undergone a process where preservatives are forced into the timber under high pressure. This provides extra longevity and an unbeatable level of protection for the wood against rot, insects and fungus. This also means the building comes with a 15 year anti-rot guarantee.

Though pressure treated timber is well protected, customers should carefully read and follow all care guidelines supplied by the manufacturer with your building. This usually involves regular treatment with a water based treatment. The manufacturer recommends Protek Wood Treatments, available to purchase through elbec at a fantastic price.

Alongside its imposing scale, this 10 x 20 workshop is unique within the range due to the addition of three adjacent windows, which multiply the amount of available sunlight several times over. This contributes to the open feel of the workshop when inside the workshop and makes it a comfortable space to occupy for hours at a time. The panes used for these windows are made from styrene, a cost effective way make sure there is no danger of shattered glass in a bustling garden environment.

This building is supplied flat packed with detailed instructions and all the fixtures needed to complete assembly by yourself. We recommend that you build your workshop with one or two trusted friends, or simply add the option to have your building professionally assembled by our team when you order.

Additional Details about Your Order

If you think that a Mercia Premium Reverse Apex Wooden Workshop would be perfect for you, take a look at our delivery information. If you would like any extra details, feel free to email us to discuss your order and our full range of product options, or better still, give us a call so we can find the perfect shed to suit your needs.

Alternatively, why not visit us at our Brookfields Garden Centre showsite near Nottingham? One of our helpful advisors will be on hand to show you around or to help guide you through your order in person. Though if there is a particular garden building you would like to see, we recommend contacting us in advance to find out if we have it, or one similar, on site.

All our sheds are supplied pre-treated with a base coat to both sides in a golden brown water based industrial product (colour can vary from the picture shown) for protection during manufacture and transit. You must apply a water based top coat of your choice in order to receive the full 10-year anti-rot guarantee. Many manufacturers recommend Protek wood treatment, available from elbec in a wide variety of different colours. This will protect the timber from weathering, making it last longer. The timber treatment will need to be repeated periodically in line with the manufacturer's instructions.

What is included?

  • 10 year anti-rot guarantee*
  • Great improvement on durability from sheds with overlapped timber
  • Ethically sourced and dip treated 12mm timber
  • Heavy duty roofing felt included as standard
  • Double doors secured by hasp and staple
  • Ledged and braced door with strong ‘Z’ shaped bracing for added security
  • Assemble at home by yourself or using our professional installers



Booking Delivery

You will be required to book your delivery date at the time of placing your order. Our 'Request a Delivery Date' service is available to the majority of areas and you'll find that the majority of the UK postcodes are FREE but some areas may incur a delivery surcharge and some postcodes are not covered at all. Select a 'requested delivery date' by entering your post code in the 'Request a delivery date' section above. You will also be notified at this time if your area incurs a surcharge or delivery is not covered in your area.

You'll be contacted on the morning of your delivery date either by text or email with a 2 hour delivery slot. You will also be contacted by the driver 30 minutes before the delivery location.

Please note: for Mercia Metal and Mercia Plastic Sheds ONLY - your order is delivered by a courier you will not be notified prior to the delivery. If you are not in on the day of the delivery you will be carded and asked to contact the courier to arrange a new mutual delivery date.

Delivery Leadtimes

The estimated delivery lead time for this product is identified on the product page above. Lead times are in working days (Monday - Friday) excludes Bank Holidays. These estimated lead times are provided by the manufacturer and are not guaranteed - due to fluctuation in demand - but are provided in good faith and are representative of delivery at that time. Some remote areas will take a little longer.

Upon Delivery

Your order is delivered either kerbside or driveway and will be delivered on a 17 ton lorry (the size of a Refuse Cart). Unfortunately due to health and safety and insurance liabilities the driver will not be able to take your goods around to the back of your property but may upon request place the product at the side of the house if there are no access or restriction issues. We would not risk damaging your property whilst delivering a product to an un-safe location. Unfortunately we will not be able to go through your property.

We would recommend against arranging for a third party to install the building before it's been delivered and checked that all parts are present, as we cannot be held liable for any third-party costs.

Installation Option

The leadtime for our installation option around 8 weeks.  With the installation option, some orders will have delivery and installation on different days, and some orders will have installation and delivery on the same day.  You will be advised by the manufacturer's installation team which category your order falls in to.

Within 3 working days of placing your order, you will be sent an installation questionnaire to complete and subsequently contacted with an installation date.

10 x 20 (3.18m x 6.06m) Mercia Premium Reverse Apex Shiplap Workshop - Pressure Treated

rrp £1920.00
save £220.01

Product code - 20010160


Description Information

A huge garden building with three opening windows and a set of double doors, the 10 x 20 Mercia Premium Reverse Apex Shiplap Workshop - Pressure Treated is the largest in its range and boasts a vast interior that could be perfect for a variety of uses, including DIY projects, storage, or even as an outdoor office. A 12mm tongue and groove construction used in its floor, roof, and all four of its walls, provides the strength and sleek appearance expected in a premium outdoor building. Key features include:

  • Large interior space suitable for a variety of uses
  • 3 opening windows help illuminate the interior with natural light
  • Pressure treated timber, with a 15 year anti-rot guarantee
  • Shatterproof styrene glazing

View full specification Delivery

Choose additional options
Protek Royal Exterior Superior Wood Finish for Mercia Products
Protek Royal Exterior Superior Wood Finish 5 litres - Sage Leaf£46.00
Protek Royal Exterior Superior Wood Finish 5 litres - Golden Oak£46.00
Protek Royal Exterior Superior Wood Finish 5 litres - Slate Grey£46.00
Protek Royal Exterior Superior Wood Finish 5 litres - Mendip Mist£46.00
Protek Royal Exterior Superior Wood Finish 5 litres - Silver Grey£46.00
Protek Royal Exterior Superior Wood Finish 5 litres - Spring Green£46.00
Protek Royal Exterior Superior Wood Finish 5 litres - Anthracite Grey£46.00
Protek Wood Stain and Protector for Mercia Products
Protek Wood Stain and Protector 5 litres - Teak£20.00
Protek Wood Stain and Protector 5 litres - Ebony£20.00
Protek Wood Stain and Protector 5 litres - Chestnut£20.00
Protek Wood Stain and Protector 5 litres - Dark Oak£20.00
Protek Wood Stain and Protector 5 litres - Silver Fir£20.00
Protek Wood Stain and Protector 5 litres - Sky Grey Blue£20.00
Protek Wood Stain and Protector 5 litres - Clear Top Coat£26.00
Protek Wood Stain and Protector 5 litres - Gun Metal Grey£20.00
OUT OF STOCK - Protek Wood Stain and Protector 5 litres - Soft Sage£20.00
OUT OF STOCK - Protek Wood Stain and Protector 5 litres - Cornflower£20.00

Your choices:

  • 10 x 20 (3.18m x 6.06m) Mercia Premium Reverse Apex Shiplap Workshop - Pressure Treated£1,699.99
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