About 15 months ago I oiled a new hardwood outside door using teak oil
I got from BeanQueue, I gave it the required 3 coats and it was fine
but recently I see the door looks like it is mildewed and doesn't seem
to have the original weatherproofness. I just wondered if this is
normal and should I have re-oiled it after 12 months ? If so then
will it need re-doing every year and what's the best way to deal with
the mildew ?