Appraisal and PA are two different things. Most, if not all policies, have an appraisal clause. Short summary, Homeowner informs their Insurance they are invoking appraisal. Homeowner appoints an independent 3rd party as their appraiser, insurance does the same. Theoretically, they both are supposed to get together and attempt to reach an agreement. If they cannot, the two parties can agree on a neutral 3rd party umpire to settle the differences. If the two parties cannot agree on an umpire, you go to the local court and ask the judge to appoint an umpire. Two parties present their case to the umpire, umpire ultimately decides on the outcome.
Note that in most cases, appraisal is to settle the difference in claim amounts, not to decide if a denied claim should be approved.
Public Adjusters are independent third parties that can be hired to represent the policy holder. A PA can legally discuss policy and usually has some clout with the insurance companies. They usually charge 10% of the total claim amount or 20% of the difference between the claim amount prior to them being hired and the final claim amount they were able to settle for. There are very good PA’s and ones that aren’t so good. Choose wisely.
Another option is to forget all that and move straight to an Attorney. Each situation is different and all the variables need to be considered to determine which approach is best.