Douglas Decking Kit 4.0 x 3.0m | 150mm Framing

Premium Douglas Fir Garden Decking Kits – 4.0m Width (Heavy-Duty 150mm Frame)

Elevate your outdoor space with our professional-grade Douglas Fir decking kits, featuring a strong structural subframe. Chosen for its superior strength and natural beauty, this 4.0m width range offers a high-end alternative to standard softwood. By upgrading the framing to 50x150mm timbers, we provide a robust foundation suitable for larger spans, elevated platforms, or heavy-duty cabin bases.

The Douglas Fir Advantage: Superior Strength & Durability

Renowned for its excellent strength-to-weight ratio and natural resistance to decay, Douglas Fir is the premier choice for a luxury garden deck. These boards feature a versatile dual-surface design: one side is relief-cut (grooved) for a classic, slip-resistant finish, while the other is planed smooth to showcase the species' famous straight grain and warm tones.

Please note: These kits are designed to be cut to size during installation. This specific range is for 4.0m width configurations with a deep-profile framing system.

Technical Specifications

Decking Board Information

• Dimensions: 4.0m length x 145mm width

• Thickness: 28mm

• Material: Premium European Douglas Fir

• Treatment: The decking boards arrive untreated; specialized treatment is supplied with each kit.

• Finish: Kiln-dried for maximum dimensional stability; dual-sided (Relief-cut/Smooth).

Heavy-Duty Framing Timber Information

• Sectional Size: 50mm x 150mm (High-Load Capacity)

• Material: High-Quality Structural Softwood

• Treatment: Arriving pre-treated in a Black finish; we supply a touch-up tub for cut ends.

• Installation: Recommended centres of 400mm (Timber must be cut to size on-site).

Installation & Foundation

This heavy-duty kit is engineered for versatility. The 150mm frame depth provides the structural integrity required for various ground conditions:

• Elevated Decks: The 150mm joists are ideal for installation on timber posts or concrete blocks, allowing for greater spans between supports.

• Log Cabin Bases: Provides a rigid, warp-resistant foundation for heavy garden buildings.

• Protection: To ensure maximum lifespan, we include Bitumen Joist Tape to seal the top of the frame against moisture trapped under the boards.

Hardware & Fixings Included

To match the structural integrity of the 150mm frame, we provide high-spec industrial hardware:

• Decking Screws: 5mm x 50mm stainless steel universal screws with a wax coating for effortless installation and ultimate corrosion resistance.

• Heavy-Duty Framing Screws: 8 x 100mm structural screws designed to fix the frame together.

• Joist Hangers: supplied for all middle joists with 4mm x 40mm reinforced screws.

• Joist Tape: Professional-grade bitumen tape provided to protect the top of all framing timber.

• Treatment: Comprehensive treatment kits for both the black framing timber and the Douglas Fir decking boards.

Dimensions for this kit:

• Max Width: 4.0m

• Max Length: 3.0m

• Total Height: 178mm (150mm Frame + 28mm Board)

Other sizes available in the 150mm range:

• DDB-4.0x3.0m-150 - 4.0 x 3.0m

• DDB-4.0x4.0m-150 - 4.0 x 4.0m

• DDB-4.0x5.0m-150 - 4.0 x 5.0m

This decking kit includes:

• 12 x 50x150x3000mm Treated Framing Timbers

• 3 x 50x150x4000mm Treated Framing Timbers

• 2 x Box of ø8x100mm Heavy-Duty Framing Screws

• 1 x Box of ø5x90mm SS Screws for Noggins

• 5 x Rolls of Bitumen Joist Tape

• 20 x Joist Hangers

• 1 x Box of ø4x40mm Screws for Hangers

• 22 x 28x145x4000mm Double Sided Douglas Fir Decking Boards

• 3 x Boxes of ø5x50mm SS Decking Screws

• 1 x Tub of Touch-up Treatment for Framing Timbers

• 2 x Tubs of Douglas Fir Decking Board Treatment

Please Note: Framing beam sizes may vary slightly depending on seasonal availability, but we will always supply sufficient structural timber to complete the deck to the specified strength.