March 2004 - Society for California Archaeology

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26 Articles already begun with the archaeological investigation and the prior removal of some of the wall coverings in the east part of the Mesa Room. Foundations To understand the adobe structural system it is necessary to have the most information possible on the foundation system. The foundation at the southeast corner of the Mesa Room is in the process of being excavated on the interior and the exterior. Figure 1 shows the interior condition. Figure 1: Detail of the foundation of the south wall at the southeast corner. A piece of flooring is at the top of the exposed stone foundation. Figure 2: A line of vertical holes drilled through the exterior hard stucco. This location is on the north side of the north wall of the Mesa Room. Discussion The original intent of Crosby’s site visit was to undertake only the condition recording phase, which is a non-invasive part of the documentation of the existing conditions. The subsequent stage of fabric investigation that will include a more comprehensive investigation of the building fabric and system analysis was to have taken place on a subsequent site visit. However, the condition of the structure with the principal building fabric and systems covered by stucco renderings and interior wood siding, paneling and gypsum board restricted the amount of information available from the initial non-invasive approach. Consequently, we began the deconstruction phase and more comprehensive fabric investigation by drilling holes through the exterior stucco in several locations. In fact this deconstruction phase had The coursing of the unshaped rocks is very uneven with large gaps and without a clear edge line. This character of this section of the foundation could have resulted from a casual construction approach. The other possibility, and a more likely one is that disturbance that may have occurred after the construction of the feature that altered the original condition. The excavation has not exposed the actual base, so any additional analysis at this point is premature. An extension of the excavation to the west of this area between the adjoining fireplace and the closed doorway may yield additional information. A comparison of foundations that had been previously exposed to the east of this structure, part of which may be an extension, may also yield important comparable information. The exterior excavation at the southeast corner was in an area that had been extensively disturbed previously and provided no additional information about the corner condition or evidence of an extension of the south wall foundation to the east. There is evidence that the present exterior east wall is an original interior wall, as the south end of the east wall did not appear to have any foundation stones with the adobes placed directly on the ground. This east wall is also approximately two feet thick, another characteristic of an interior wall. From the standpoint of developing a more clear understanding of the condition of the building, it will be important to continue the investigation of the foundations. Adobe Walls Although the fabric investigation is in its early stages, it does appear that the four walls of the Mesa room are adobe construction. There appears to be one missing section of adobe in the south wall and there are other sections where the adobe wall has been altered. The specific extent of these missing sections and alterations will be identified further in subsequent work associated with this project. The evidence of the adobe was available from observations in the attic of both adobe rooms as well as from the attics of the adjacent rooms to the south of the Mesa Room. There are also some missing sections in the adobe walls of the De Anza Room as well, but the majority of the wall fabric of all four walls of this room is adobe construction. The existence of the adobe was also confirmed by drilling holes through the hard exterior stucco in several locations of SCA Newsletter 38(1)
27 Articles both buildings. The purpose of drilling the holes was primarily to determine the extent of the hard stucco, identify the wall material and collect information on the condition of the immediate substrate. Figure 2 shows one of the areas where holes were drilled through the stucco. The holes were drilled with a power drill with a 1/2” masonry drill until the stucco was penetrated. At that point, the drilling continued at a reduced rate and the materials from the drill holes were examined. Later each hole was probed with a steel probe and a brass tube. The brass tube was used to extract small material samples in some cases. The brass probe was pushed into the substrate by hand, and this also provided an idea of the relative softness of the substrate materials. Additional holes will be drilled to provide more of the basic information available through this process. The preliminary results from the drilling are (1) the stucco appears to be reasonably uniform in material and thickness, (2) the walls are composed of adobe masonry, (3) there is some variation in the dampness of the adobe walls, and (4) the north walls of the two adobes are damper than is the east end wall. The relative dampness was not unexpected, as the north side appears to be the wettest side of the structure. The location and extent of the dampness also appears to indicate that there is not a systemic ground moisture problem that affects the integrity of the adobe walls, but rather is localized and probably the results of watering and the accumulation of surface runoff along the front of the structures. There are two important pieces of additional information that will help to understand the threat of moisture to the adobe walls more comprehensively. First is the effect that the wet season or a wetter year will have; second is the actual subsurface condition of the site. Additional testing and research will provide this information. The results of the drilling indicates that to better understand the wall conditions in some areas, some of the hard stucco will have to be removed. The result of the drilling was discussed with project team members and several areas were identified where the stucco would need to be removed to expose more of the actual wall fabric. The two initial areas are to be on the east of the Mesa Room. The purpose of the stucco removal at this location is primarily to determine the condition of the adobe wall and the connection of the east and south walls. Stucco on this same east wall near the northeast corner will be removed in a similar way and for the same purposes. In this latter case, the stucco should be removed to the existing ground line and an excavation unit should be placed at the same location. The drilling showed evidence of stone at the base of the wall, which is somewhat inconsistent with the present understanding of this wall derived from the interior excavation. The excavation should also provide additional information on the foundations systems in general. The exterior wall surfaces were also mapped on sketch drawings, locating wall bulges, stucco patches, cracks and Figure 4: A detail of the top of the south wall near the fireplace and the closed doorway in the Mesa Room showing the location of a deep structural crack that is on axis with the wall plane. The view is looking directly down on the top of the wall other indications of wall conditions. The interior wall surfaces were not mapped as all the interior walls are covered with combinations of wood siding and gypsum board. Several cracks were located and mapped on the elevation drawings. Most were very typical and do not appear to reflect a response to a severe structural condition. One crack does appear to be active and a crack monitor will be installed on that crack in the future. The adobe wall was investigated from several different areas of the attic, but the access was extremely limited because of the configuration of the roof system. Eric Blind examined the gable of the east wall and we both were able to check the top of the south wall of the Mesa Room. In order to gain a greater understanding of the walls more areas need to be accessed and examined. There is some evidence that the adobe wall has suffered structural trauma in the past. The short section of wall between the fireplace and the closed door in the east part of the Mesa Room had what appeared to be a significant crack and a deep fissure. The top of the wall was partially cleaned, but more cleaning and the exposure of more of this wall is needed. This will be done during the next site visit. Figure 3 is a detail of this part of the wall. Roy Tolles, project structural engineer visited the site on Thursday and after an initial examination we decided that, rather than returning immediately to complete his investigation, it was more practical to wait until more of the adobe wall was exposed. This will be coordinated with the next site visit, which will probably take place in March. Roof System The existing roof system is a combination of what appears to be a mid-19 th century roof and modifications to the ca. SCA Newsletter 38(1)
Page 1 and 2: Founded 1966 Volume 38, Number 1 Ma
Page 3 and 4: 3 I’m looking forward to seeing a
Page 5 and 6: 5 SCA Business and Activities Senat
Page 7 and 8: 7 Water, Clean Air, Safe Neighborho
Page 9 and 10: 9 News and Announcements The Cultur
Page 11 and 12: 11 Anthropology.” Forensic anthro
Page 13 and 14: 13 Out of the Pits group and that t
Page 15 and 16: 15 Field Notes Gundrum left Fort Ir
Page 17 and 18: 17 2004 Annual Meeting Ongoing Acti
Page 19 and 20: 19 Articles U.S. to claim they had
Page 21 and 22: 21 Articles Figure 5 site. Data wer
Page 23 and 24: 23 Articles that guides the visitor
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Page 29 and 30: 29 Articles Culture Contact at El P
Page 31 and 32: 31 Articles As noted above, the sho
Page 33 and 34: 33 Articles and analyzing this coll
Page 35 and 36: 35 Articles rescued and the finders
Page 37 and 38: 37 Articles firing two security fir
Page 39 and 40: 39 Articles A Brief History of Russ
Page 41 and 42: 41 Articles family…. (Brightside
Page 43 and 44: 43 Articles Baker, Joseph, ed. 1914
Page 45 and 46: 45 SCA Newsletter 38(1)
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March 2004 - Society for California Archaeology

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