I keep getting a data type mismatch. What am i doing wrong on the addition??

If Worksheets("Int Project").Cells(Row, 186) 0 Then Worksheets("Int
Quote").Cells(Row, 109) = "Doors & Frames - " & "Apply " &
Round(Worksheets("Int Project").Cells(Row, 184), 0) & " Coats " & "- Time: ("
& (Worksheets("Int Project").Cells(Row, 72).Value + Worksheets("Int
Project").Cells(Row, 78).Value) & " hours)" & " " &
Worksheets("Int Project").Cells(Row, 186) & " Gallons of ____________"
'Average Doors and Frames

Thanks..