Conserving wooden block floors
The use of Endgrain timber for tiles and cobbles is centuries old. They were primarily used as a surface for paving and roads with the first blocks being round or hexagon. Many town and city streets and pavements in Europe, America and Russia, were paved with wooden Endgrain cobbles especially in the 19th and early 20th century. This provided a better surface for horses and wagons with their iron rims. It was also used as a floor surface in many factories and warehouses.
Most of them were set in coal tar/pitch and it would be sensible to use this medium for repairs.
If you want to re-point between the timbers externally you can use a hydraulic lime (HL) – Use Tradiblanc at a ratio of 1 bag of Tradiblanc to 90 litres of aggregate.
You could alternatively fill liquid pitch at the bottom of the joints and do the top 35mm in lime mortar – the Tradiblanc will have excellent adhesion to the pitch.