Bodge is the right word ... my mate had his roof sprayed from the inside by some blokes wearing Stetsons and the finish did look good ... no leaks, no droughts, no daylight poking through .... then a few years later he was suddenly presented with a 'FREE' veloux type skylight when a whole section of the roof caved in with dry rot riddled all over the place ... keep away ... if the roof is leaking it's better to let it leak until you can get it fixed properly.
Ash Some mornings it's just not worth chewing through the leather straps !