Ceiling system

A method of covering a ceiling support with a plurality of ceiling panels, each of the ceiling panels comprising an upper face, a lower face opposite the upper face, a first edge, a second edge, a third edge opposite the first edge, and a fourth edge opposite the second edge, each of the first and second edges comprising a tongue, and each of the third and fourth edges comprising a groove, the method comprising:

• a) mounting the ceiling panels to the ceiling support in an interlocked arrangement so that the tongues of the ceiling panels nest within the grooves of adjacent ones of the ceiling panels, the ceiling panels mounted so that the upper faces of the ceiling panels oppose a lower surface of the ceiling support;
• and
• b) during step a), positioning an alignment clip having a cruciform rib element at an intersection of four of the ceiling panels, the cruciform rib element of the alignment clip maintaining the four ceiling panels in orthogonal alignment with one another.