After excavation exposed them to erosion, floors and wall segments required ongoing preservation treatments. Buildings held together with mud mortar required regular upkeep, and after the original residents moved on, the mortar eroded, causing roofs and walls to collapse. Rubble filled the rooms, burying and protecting lower wall sections and room floors, including fire hearths and post holes from timbers supporting the roofs. Excavation removed this protective fill, subjecting floors and walls to erosion and deterioration. As a result, rooms needed modern protection measures including cementing walls, placing capstones, adding drains to keep water from standing in the rooms, and covering floor features with dirt. Some early preservation efforts, though well intended, can be mistaken for original construction, while others cause damage. Because concrete traps moisture in the walls, preservation specialists today remove concrete mortar and replace it with soil cement, a mixture that replicates the original mortar. Current preservation efforts aim to protect structures without altering original construction methods or materials. Soil-based mortars allow walls to breathe and moisture to escape, but they also erode readily and require periodic reapplication, so the site requires constant maintenance.