Split your purchase of £19.80 into 3 with no sign-up fees or late fees.
£6.60
today
£6.60
1 month
£6.60
2 months
How it works
Choose PayPal at checkout to pay later with Pay in 3.
Complete your purchase with the first payment today.
Remaining payments are taken automatically.
Pay in 3 is a form of credit, so carefully consider whether the purchase is affordable and how you will make the repayments. Be aware of the possible impact of using Pay in 3 and of missing payments, including making other borrowing more difficult or more expensive. Pay in 3 eligibility is subject to status and approval. 18+ UK residents only. Available for purchases of £30 to £2,000. Terms and conditions apply. PayPal Pay in 3 is a trading name of PayPal (Europe) S.à r.l. et Cie, S.C.A. 22-24 Boulevard Royal L-2449, Luxembourg.
Get what you need for your next project, choose how you pay.
Pay in 30 days
£19.80
Pay in full
Klarna's Pay in 30 days is an unregulated credit agreement. Borrowing more than you can afford or paying late may negatively impact your financial status and ability to obtain credit. 18+, UK residents only. Subject to status. T&Cs and late fees apply.
Pay over time
£6.60 Every 30 days
Pay in 3
£6.60
today
£6.60
in 30 days
£6.60
in 60 days
Klarna's Pay in 3 is an unregulated credit agreement. Borrowing more than you can afford or paying late may negatively impact your financial status and ability to obtain credit. 18+, UK residents only. Subject to status. T&Cs and late fees apply.
How it works
At checkout select Klarna.
Choose your payment plan.
Different payment plans may be shown depending on the purchase amount and credit score.
Complete your checkout.
The amount will be charged based on the payment plan you chose.
Split your purchase of £19.80 into 4 with no sign-up fees or late fees. Your purchase will be split into 4 payments, payable every 2 weeks
£4.95
today
£4.95
second payment
£4.95
third payment
£4.95
fourth payment
How it works
Choose Clearpay at checkout to pay later with Pay in 4.
Complete your purchase with the first payment today.
Remaining payments are taken automatically.
Clearpay is unregulated credit. Use responsibly. 18+, T&Cs and late fees apply at clearpay.co.uk/en-GB
Clearpay lends you a fixed amount of credit so you can pay for your purchase over 4 instalments, due every 2 weeks. Ensure you can make repayments on time. You must be 18+ and a permanent UK resident (excl Channel Islands). Clearpay charges a £6 late fee for each late instalment and a further £6 if it’s still unpaid 7 days later. Late fees are capped at £6 for orders under £24 and the lower of £24 or 25% of the order value for orders over £24. Missed payments may affect your ability to use Clearpay in the future and your details may be passed onto a debt collection agency working on Clearpay’s behalf. Clearpay is credit that is not regulated by the Financial Conduct Authority. T&Cs and other eligibility criteria apply at clearpay.co.uk/terms
£19.80ex. VAT
Ask Kev:
Key Features
{{foundation}} Used in a variety of structural applications
{{water_drop}} Offers load-bearing performance in humid conditions
Technical Specification
Technical Specification
URN:
4003002
Application:
Roofs & walls
Material Type:
OSB
Thickness:
18mm
Width:
1220mm
Length:
2440mm
Weight:
28kg
Sales Unit:
Sheet
Sales Unit Coverage:
2.98m2
Moisture Resistant:
Yes
Product Standard:
BS EN 300
Grade:
OSB3
Wood Species:
Pine / Spruce
Edge:
Square
Bond Class:
BS EN300
Colour:
Natural
Finish:
Unsanded / Smooth
Formaldehyde Level:
E1 (low)
Country of Origin:
Latvia
Product Overview
Structural OSB 3 Sterling board, measuring 2440mm x 1220mm (8' x 4') with an 18mm thickness.
Engineered from cross-laminated softwood strands and bonded with resin under heat and pressure, it delivers consistent strength and stability without knots or voids.
Certified to EN 300 OSB 3 for load-bearing performance in humid conditions, it serves as a practical and cost-effective alternative to plywood for many structural applications such as heavy flooring, robust roofing, and demanding joinery or construction work.
Features & Benefits
Structural classification: OSB 3 certified to EN 300, for load-bearing use in humid conditions.
BBA approved: Permits use in a wide range of commercial and domestic projects.
Void-free construction: Consistent strength with no knots or core gaps.
Cross-strand stability: Resists warping, splitting, and expansion.
Workability: Easy to cut, drill, nail, and sand with standard tools.
Board size 2440mm x 1220mm: Compatible with UK framing centres for straightforward fixing on standard stud/joist spacing.
Thickness 18mm: Heavy-duty board for flooring, roofing, and high-load applications.
Applications
Flat roof decking: Structural 18mm profile provides the rigidity required for GRP, EPDM, and felt roofing systems across joist centres up to 600mm.
Timber frame sheathing: High-capacity 18mm boards provide essential racking resistance and load-bearing support for structural wall and floor panels.
Site hoarding and security: 18mm thickness ensures a robust, impact-resistant barrier for secure temporary site enclosures and perimeter fencing.
Shed and outbuilding flooring: High-density construction eliminates floor deflection under the weight of heavy garden machinery and workshop equipment.
Concrete formwork and shuttering: High-strength board serves as a containment solution for foundations and walls where a textured concrete finish is acceptable.
Mezzanine and storage platforms: 18mm thickness provides a certified structural deck for internal mezzanine levels and heavy-duty shelving in warehouse environments.
Sarking and roof boarding: Used beneath primary roof coverings to provide a secondary moisture barrier and increase the overall rigidity of the roof structure.
Installation Guidance
Allow for expansion: Leave a 3mm expansion gap between all board edges and a 10mm gap at rigid wall abutments to accommodate natural movement.
Stagger the joints: Lay panels in a "brick-bond" pattern across supports to ensure structural loads are distributed evenly across the frame.
Support all edges: Ensure every board edge is supported by a joist, stud, or noggin to prevent deflection and maintain a level surface.
Apply correct fixings: Secure boards using galvanised nails or screws at 150mm intervals along edges and 300mm intervals on intermediate supports.
Seal cut edges: Coat all field-cut edges with a high-quality water-resistant wood sealant immediately to prevent moisture ingress and edge swelling.
Orient boards correctly: Install the long axis of the board perpendicular to the supporting joists or studs for maximum structural spanning strength.
Protect from weather: Cover installed boards with a waterproof membrane as soon as possible if the structure is not yet fully weathered.
Fixing distance from edge: Ensure all fasteners are driven at least 10mm from the board edge to prevent breakout and maintain pull-through resistance.
Surface painting: Use a high-quality solvent-based primer or dedicated OSB sealer before applying topcoats to prevent strand swelling, as detailed in our comprehensive guide to painting OSB.
Compliance & Performance
Standard: EN 300 OSB 3 classification, verified for structural use in humid environments.
Certification: BBA approved for quality and compliance in construction.
Bonding: High-pressure, resin-bonded layers provide long-term durability and resistance to delamination.
Veneer quality: Free from internal knots and core voids, ensuring consistent structural integrity across the board.
Important note: Colour and finish are representative only and may vary slightly as this is a natural product. Always ensure proper ventilation if using in enclosed spaces, though this board is manufactured to E1 low-formaldehyde emission standards.
Delivery & Returns Information
Delivery charges vary by product category and order value. Items may ship from different suppliers and arrive separately, so delivery charges can be shown per part of your order at checkout.
Standard (Nationwide) Delivery
Core Products
Core
ORDER VALUE
DELIVERY CHARGE
Under £200
ex. VAT
£15
ex. VAT
Over £200
ex. VAT
FREE
Core Delivery is our most competitive delivery fee. To qualify for Core Delivery, all the products in your basket need to be from our Core range. Core products have the Core icon next to their picture.
Timber & Sheet, Building Materials, Joinery and Gardens & Landscaping Products
ORDER VALUE
DELIVERY CHARGE
Under
£300
£30
ex. VAT
Over
£300
ex. VAT
FREE
Express Delivery
Express Delivery - Timber & Sheet, Building Materials, Joinery and Gardens & Landscaping Products
We work with a nationwide network of trusted suppliers. Items in your basket may be supplied by different suppliers and delivered separately. Where this applies, you will see delivery charges shown at checkout for each part of your order. We always aim to group products from the same supplier to keep delivery costs as low as possible.
Delivery areas
Delivery charges apply to mainland UK, excluding: AB, CA, CF, DD, DG, EH, EX, FK, KA, KW, KY, IV, LA, LD, LL, ML, NP, PA, PH, PL, SA, SY, TR, TQ and TD.
If your address is in one of these areas, we will contact you before processing your order to confirm any additional costs. We do not currently offer delivery outside the UK mainland.
What to expect on delivery day
Deliveries are typically kerbside.
Please ensure someone is on-site to accept delivery. For heavier items, help with offloading may be required.
Many building materials arrive on large vehicles. If access is restricted, a specialist vehicle such as a HIAB may be required and could incur an additional charge.
Why delivery can cost more than typical parcel delivery
Building materials often travel on larger vehicles and usually carry fewer drops per run than parcel networks. That is why delivery charges can be higher than standard e-commerce shipping.
Returns
Returns depend on what you have bought and whether there is anything wrong with it. For full details on eligibility, timeframes, and exclusions, please see our full policy.
Plywood is made from thin layers of wood veneer glued in alternating directions, while OSB3 (Oriented Strand Board) is made from compressed wood flakes and resin.
Can 18mm OSB3 be used for flat roofs?
Yes. It is strong enough to span roof joists and provides a stable, moisture-resistant base for waterproof membranes like EPDM rubber, GRP fibreglass, or felt.
Is 18mm OSB3 better than 11mm for flooring?
Yes, 18mm OSB3 is the standard minimum thickness for structural flooring. 11mm is not designed to support the weight of people, furniture, or equipment without snapping or sagging.
Learn more
Learn more
Learn more
