Real carriage house doors were historically built using exterior strap hinges with lag bolts or screws as fasteners to secure the door to the building. Use of these types of fasteners is just asking for BIG TROUBLE! These fasteners create a large hole for water to go directly into the wood core generating wood rot and door failure. Think about it – you only see this type of fastener on a barn door or garden gate, never an entry door to a house. Hinges are mortised into the side of doors for a reason – protection from the elements and strength.
