Knee Rail Fencing with 1.8m Top Rail - Calculator

Build your own Knee Rail system - 1.8mTop Rail

Introducing Timber Knee Rail Fencing, a resilient construction method that employs the 'birdsmouth' jointing technique to craft a durable and visually appealing structure. This fencing style features horizontal rails securely supported by vertical posts, commonly known as birdsmouth, ascot, or diamond fencing within the industry.

Please note: Timber knee rails do not meet the specifications for highway use

Key Features and Applications

The designation 'Knee Rail' stems from its deliberate placement at a low level around knee height, serving to demarcate boundaries while maintaining unobstructed sightlines. The birdsmouth joint, defined by a precise notch at the timber's end fitting onto the post, significantly helps structural integrity by maximising the connection between horizontal rails and vertical posts.

This fencing style predominantly utilises resilient, decay-resistant timber, making it well-suited for outdoor settings. Comprising top rails, birdsmouth posts, and secured with galvanised straps (available in several styles) and nails, the assembly ensures a steadfast and enduring linkage between timber posts and rails. The installation process involves ground excavation.

The adaptability of Knee Rail Fencing allows for its application in diverse settings such as car parks, pathways, and walkways. While easily stepped over, it effectively delineates boundaries, dissuading trespassing on lawns or flower beds, and organises designated parking areas. Its cost-effectiveness positions it favourably for public spaces where heightened security is not the primary concern.

Choose the meterage of your run, then select birdsmouth posts, fixing straps and sundry items such as nails and post mix. The top rails are available in 3.6m and 1.8m lengths and in a width of 75 x 75mm and 100 x 100mm and they are a rough sawn timber. The posts undergo thorough pressure treatment with Tanalith E Green, a copper-based biocide product ideal for environmentally sensitive applications. When exposed to the outdoors, the initially pale green timber gracefully transitions into a beautiful honey colour before settling into a silvery grey hue. This timber knee rail fencing is supplied to First Fence by a reputable UK timber saw mill, produced from Norway Spruce and felled predominantly from North Wales (FSC certification is available upon request).

Designed for in-ground installation, the birdsmouth posts require Post Mix to ensure stability and durability. It is recommended the posts are installed at 1.8m post centre intervals. Knee Rail Fencing is typically 450 or 600mm high so the recommendation is to dig half the length of the post into the ground. A minimum of 2 bags of Post Mix per post is suggested.

The Bishop's Hat style fixing strap is suited to the 100 x 100mm top rail as there will be an overhang on the Birdsmouth post, whereas the 75 x 75mm top rail will need the V straps or Shoe straps.

While the timber posts undergo initial treatment, additional wood treatment, especially on the ends, is recommended to enhance their resilience and prolong their lifespan.

Get in touch!

If you need any help then please get in touch and a member of the sales team will be happy to guide you through your purchase. The team can be contacted by calling 01283 512111 or by using the online chat tool.