Hi Bluebelly.
Unfortunately , at 38 mph, you will find it very difficult to prove that winds of that force blew your roof off , an adjster will more than likely put it down to the roof being in a state of needing repair in the first place to which you will not be insured .
If you have not already done so , You need to formaly write to the adjuster at the insurance company to complain against their decision . The adjuster then has to review your details , who should then write back to you with an outcome of the review, formaly , with details of the outcome of of why their decision has been made . They should include in their letter the email, or address of the the Financial ombudsman Service to complain or to make an appeal against their decision, there is no point going to them first if you have not formaly complained to the loss adjuster, as they will just send you back to them .
Hope this helps a little x