Since 1973 a number of field tests have been undertaken in conjunction with an on-going laboratory program in experimental mudbrick conservation sponsored by MASCA at the University Museum of the University of Pennsylvania. The field test areas include Arizona, Florida, Pennsylvania, Iran and Guatemala. Both Laboratory and field experiments have shown that the soaking of mudbrick in dilute solutions (2-3per thousand) of certain hard and soft method acrylic polymers resulted in significant penetration, binding and waterproofing. Furthermore, the incorporation of acrylic emulsions in mudbrick and mud plaster markedly strengthened brick and surfacing against weathering due to precipitation and cyclical freezing.