Hello! 1st post here. We had a contractor install a set of french doors that took the place of a sliding glass door that leads to a concrete breezway between the house and the garage. With the french doors installed, there is nothing to support the threshold. With the sliding door in place it was not a worry, but without removing the french doors how can I support the threshold? Wood will not work due to rain water entering the breezway. Can I concrete under the threshold somehow? Thanks for any help!!