Field mulling system for windows and doors

A mulling assembly for field mulling a plurality of fenestration assemblies in an opening, the mulling assembly comprising:

• a first mull halve having an interior side and an exterior side;
• a second mull halve having an interior side and an exterior side;
• a first mull connector coupled to the interior side of the first mull halve and the interior side of the second mull halve, the first mull connector having an H-shape;
• and
• a second mull connector coupled to the exterior side of the first mull halve and the exterior side of the second mull halve, the second mull connector having an H-shape;
• the first mull halve being secured to a first side of a first fenestration assembly and the second mull halve being secured to a second side of a second fenestration assembly, wherein the first mull connector is secured to the interior side of the first mull halve and the interior side of the second mull halve in a direction perpendicular to a first plane defined by an interior side of the first fenestration assembly and a second plane defined by an exterior side of the second fenestration assembly, where the first plane and the second plane are perpendicular to a third plane defined by the first side of the first fenestration assembly and perpendicular to a fourth plane defined by the second side of the second fenestration assembly.