Lime render on oak beams

[Anonymous]

I am in the middle of a restoration project and after repairing an existing floor and removing some the internal cement based render/plaster i have discovered that the lintel over my window is only a piece of 50x100mm softwood lintel. I am thinking of placing a reclaimed oak beam underneath the 9 inch wall. by doing this it will be visable on the external wall. The final plan is to lime render the exterior and cover this oak beam externally. Do i need to take any precautions to the oak externally before rendering or is it ok to render straight over the oak. The existing cottage is built circa 1830 and is brick built.

 

[Anonymous]

Lime tends to have a preservative effect on timber. The oak timbers in old houses were often lime-washed for this very reason (as well as for aesthetics).