Max & Alex's lockdown railway sleeper project

Aim of the Project - to remove and replace a well used traditional decked area with something a bit more substantial - (new oak railway sleepers) - that would endure for years to come.
Alex and I had a really enjoyable few weeks across the summer working on this project. We completed mid August and had a great Bank Holiday  weekend and some fine weekends throughout September when we were able to enjoy the new deck. After removing the old deck boards and base frame, foundation channels were dug to accommodate a base structure of  3.6m  x 250mm x 125mm  new pine railway sleepers. Half length railway sleepers were used for the extended terrace area. The base structure railway sleepers were set on pilons of concrete/postcrete, level and clear of surrounding earth. As discussed with Jerry our calculations were based on minimal cutting of railway sleepers. By careful planning and calculations we were able to achieve a deck consisting of full and half boards only and also a base structure subframe consisting of full and half length railway sleepers only. Weed resistant membrane was used to line all under deck and border areas.
The top decking boards were new Canadian  oak  2.44m x 220mm x 65mm. (slight adjustments to the subframe location were required as the length of the boards averaged 249mm.- a quick fix though). Each full top board was fastened in position with 6 timberlock screws and each half board with 4 timberlock screws. A spacer gap of 5mm has been left between each board. The oak railway sleeper boards have also been used to provide a skirting board along the front edge of the deck, whilst also replacing two areas of border edging and topping fixed via postcrete fastened fence posts. 15mm oak dowel has been used to plug all drilled holes. Sanding - next time I'll get a bigger sander. We oiled the oak with Ronseal decking oil with uv protector, which really brings out the fantastic grain and character in the wood.
Fitted a few border lights during the project and finished it all off with Graphite grey Welsh slate 40mm for the borders and 20mm gravel for the skirting edging. So far the shrink and stretch on the oak boards has been minimal, and although the wet weather has caused a bit of discolouration, the oiling seems to have worked well. 
We are very happy with the end product. Thanks for your advice and guidance at the planning stage.
Max and Alex 
Carlton, Nottingham

New oak railway sleepers:
2.44 x 220mm x 65mm
New pine eco friendly railway sleepers
3.6m x 250mm x 125mm
Timberlok Screws (100mm) Says.. supplies new and used hardwood & softwood railway sleepers throughout the UK.
Many thanks to Max and Alex for their wonderful photos and the really helpful and precise description of the different stages in the construction of their oak railway sleeper decking project. It's great that some positives have come out of the corona virus lockdown, as people have spent more time on re-designing their gardens! You have created a fabulous oak decking area that looks so attractive, and will enable years of garden relaxation.