A combustor assembly includes a hot skin of a combustion chamber wall having an inner face exposed to the combustion chamber and an opposite outer face, a receiving skin having a securing portion affixed to the hot skin outer face in an air-tight manner and a receiving flange, extending from the securing portion, that is offset from the hot skin outer face to form a female recess, a cold skin having a cold wall portion spaced from the hot skin and forming a cooling cavity therebetween, a securing portion extending from a first end of the cold wall portion affixed to the hot skin outer face in an air-tight manner and a male flange extending from a second end of the cold wall portion opposite the first end, the male flange snugly received in the female recess and forming a sliding engagement therebetween.