For strong, durable outdoor surfaces that stand up to Ireland’s unpredictable weather, Decking 150 x 35 x 4.2 m Treated Timber is a reliable choice for both trade professionals and DIY builders. Made from pressure-treated timber, this decking board is designed to resist rot, decay and insect attack — making it ideal for patios, garden decks, walkways and entertaining areas.
At 150 mm wide and 35 mm thick, this robust board provides a comfortable underfoot surface and excellent structural performance across long spans, while the 4.2 m length helps minimise joints and waste on larger projects. Timber sizes are nominal and may reduce slightly after machining, so you can expect a finished size approximately 4 mm to 8 mm smaller than advertised.
Pressure treatment gives this decking timber enhanced protection against moisture and biological decay, helping to extend its lifespan with proper installation and maintenance. Whether you’re building a new deck from scratch or refreshing an existing outdoor platform, this treated decking board delivers value, strength and classic timber aesthetics that can be stained or finished to suit any outdoor design.
Key Features
Durable Pressure-Treated Timber: Protection against rot, decay and insect attack for outdoor use.
Generous Size: 150 mm wide and 35 mm thick for a sturdy deck board profile.
Long Length – 4.2 m: Reduces joints and waste across larger decking areas.
Nominal Sizing: Finished dimensions may be slightly smaller after machining — always allow for this when planning.
Versatile Outdoor Use: Perfect for garden decking, patios, walkways and outdoor platforms
Technical Specification
Product Code: D1503542
Product Type: Pressure Treated Decking Board
Nominal Dimensions: 150mm x 35mm
Length: 4.2 Metres
Finished Size: Approximately 4–8mm smaller after machining
Timber Type: Softwood
Treatment: Pressure Treated for external use
Use Class: Suitable for above ground exterior applications
Fixings: Use exterior-grade or stainless steel decking screws
Installation Note: Allow adequate spacing for expansion and drainage
Ideal Applications
Residential & commercial decking
Patios and outdoor entertaining zones
Garden walkways and pathways
Elevated decks and platforms
Garden Beds & Planters
TJ’s Tip
When installing, leave an appropriate gap between boards to allow for natural timber expansion and drainage. Use corrosion-resistant fixings designed for decking to ensure long-lasting performance — especially in exposed outdoor conditions. Regular sealing or oiling will help maintain appearance and protect against weathering over time.
We offer reliable delivery services throughout the Republic of Ireland, with straightforward delivery charges for both trade and DIY customers. Delivery options are confirmed at checkout based on your order and delivery Eircode.
Delivery Charges & Delivery Times
Delivery Type
Delivery Area
Delivery Charge
Delivery Time
Small Items
Republic of Ireland
€9.99
3–4 working days
Large & Heavy*
Standard delivery area
€29.99
5–7 working days
Extra Large*
Standard delivery area
€50.00
5–7 working days
Paint 5L or less**
Standard delivery area
€19.99
5–7 working days
Swipe sideways to compare delivery options.
Small Items
Delivery area
Republic of Ireland
Charge
€9.99
Delivery time
3–4 working days
Large & Heavy*
Delivery area
Standard delivery area
Charge
€29.99
Delivery time
5–7 working days
Extra Large*
Delivery area
Standard delivery area
Charge
€50.00
Delivery time
5–7 working days
Paint 5L or less**
Delivery area
Standard delivery area
Charge
€19.99
Delivery time
5–7 working days
*Standard delivery policy. Promotional delivery rates may apply during campaigns.
Additional Information
FREE delivery on eligible Small Items and Large & Heavy orders over €1,499, within the standard delivery area only.
Special Order and Catalogue Products require an additional 5 working days.
FREE collection of old appliances is available through WEEE Ireland when purchasing qualifying large appliances.
FREE Click & Collect is available for items in stock at your selected branch.
Large & Heavy and Extra Large items are available within our standard delivery area only.
Paint delivery Paint in tin cans 5L or less is available for delivery. Larger sizes and paint supplied in plastic buckets are available for Click & Collect only.
TJ O'Mahony offers a 30-day returns policy on eligible unused products, giving you additional time beyond the statutory 14-day cooling-off period applicable to most online consumer purchases.
Eligible products can be returned for a refund or exchange within 30 days of delivery or collection, provided they are unused, in their original and re-saleable condition, complete with all supplied parts and accessories, and accompanied by proof of purchase.
Please note: Return restrictions apply to certain products, including Mixed Paint, certain Bagged Building Products, Solid Fuel, Special Order, Non-Stock and Catalogued Products.
Your statutory rights in relation to faulty, damaged, incorrectly supplied or non-conforming goods are not affected.
