if i was you i would be looking to find a fly sheet to go over it rather than rely on the 1500mm HH it currently has, umbrellas are about the same level of waterproofing
Yes....many are designed that way, but one which comes without an inner as standard, although one could add a specific inner, I chose instead to source another and saved a lot of money.
Never been that keen on spray on proofers although have used Fabsil on a cotton canvas tent, but now prefer not to use at all, and especially not to make up for any inherent inadequacies.
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