Hi,
I am curious to know what this occupation was, I worked all my life in the timber/building trade and seem to sense that it may be something to do with preparing laths on ceilings and walls ready for the plasterer to plaster onto, I may be totally wrong, any ideas?
melm 
There is much confusion between two entirely different verbs, 'to rend' and 'to render'. What these guys did was rend, not render. They split wood, they didn't plaster walls. The guys who plastered (or rendered) walls would have used the lath render's product, which is an unfortunate coincidence that simply adds to the confusion, and it doesn't help that the verb 'to rend' is rarely used these days, other than in expressions like "let no man rend asunder". Renders would rend wood asunder. Gardeners were also customers, using laths to make trellis work.
A pale render would also have split wood, typically chestnut I believe, to make fences, the palings joined by twisted wire. As a child in the 1950s in Lancashire our gardens were separated by such fences, and everyone referred to them as chestnut palings.
To call a lath render a lath renderer is as mistaken as calling a gardener a gardenerer or a footballer a footballerer, and the idea that he plastered walls arises from that error. Sadly, it's almost commonplace to see the mistake on family history websites, but the Victorian census enumerators understood well enough they were lath renders.
