Development of Maintenance and Conservation Methods for Historical Architecture Using Plaster Wall Materials

Part8 Strength Properties of Lath and Plaster Ceilings by Cross Sectional Shape Factors

Abstract

This paper deals with the lath and plaster ceiling with trapezoidal cross-sectional wooden laths. We conducted adhesion and shear strength tests and compared the results with different cross-sectional shapes of wooden laths. The results show that the strength of rectangular cross-section laths is easily affected by the skill of the plasterer. The reason for　this is due to the shape of the “Plaster key”, and the trapezoidal cross-section lath is shaped so that the “key” cannot be removed. Therefore, trapezoidal cross-section lath is not affected by the skill of the plasterer, and its strength is stable.