68 and 70 Navy Street

68 and 70 Navy Street. . The original structure at 68 and 70 Navy Street, built circa 1850, featured stacked plank interior and exterior wall construction, a very unique building method in Ontario. This is the first known example of stacked plank building in Oakville., The building was changed and added to in the early and mid-20th century but the original stacked plank walls largely remained. Unfortunately, due to water damage over the decades, the walls were no longer structurally sound when they were re-discovered in 2021. The original form of the building has been reflected in the new structure, but the stacked planks were not salvageable. , What is Stacked Plank Construction? , Rough sawn planks from local mills were stacked and secured with forged square nails and mortar. The construction method was simple, with the planks stacked and each offset from the plank below to form a tooth for later finish. A timber sill was placed at each floor level. Planks were lapped at inside and outside corners to form a strong, square bond. See illustration., The result was uniform and rigid walls that were then typically covered in plaster on interior faces and rough-cast concrete on exterior faces. This created a high-performing wall assembly that was significantly warmer, dryer, stronger and better sealed than any other available technology., Why is Stacked Plank Construction Unique? , Stacked plank construction is known to have occurred historically where there was a plentiful supply of sawn lumber available at low prices (a local lumber boom) and so its presence is indicative of both economic factors and advances in milling technology. The brief windows of local lumber booms across Ontario coincide directly with the use of stacked plank construction., This construction technique is a way of understanding the economic and social progress of developing communities in Ontario, as well as advances in building technology. The number of buildings that were built with this method is unknown, but the number remaining in Ontario is thought to be less than 50. Some stacked plank buildings may remain unknown, as the secret of their construction lies hidden between their walls. Where stacked plank buildings were known to exist, it became common for them to be taken apart for their wealth of lumber following the rise of lumber prices.