Truss Uplift, Unbraced Cripple Wall, Misplaced Pier, and Other Structural Problems GENERAL INFORMATION Weather Conditions: Sunny, 50° Name of Homeowner(s): Mr. Larry Smith Parties Present During the Field Inspection: Mr. Smith and WIlliam A. Stanton of Criterium-Stanton Engineers. Purpose of the Investigation Determine the cause(s) of the cracks between the walls and ceilings on the second level. Determine the cause(s) of the ridge in the study floor. Determine the adequacy of the piers and wood supports under the first floor. Determine if the girder support under the left stairway wall needs a pier. Check structural repairs that were made to the wood supports under the first floor bathroom. Determine if the cripple foundation wall has adequate strength. Provide an estimate of the costs to make necessary repairs. Source(s) of Information Interview with Larry Smith. House construction plans by ABC Homes, Inc. Homeownerís Manual by ABC Homes, Inc. Watts Engineering Structural Investigation Report dated February 20, 1998. Orientation Unless otherwise stated, all directions (left, right, rear, etc.) are in relation to an observer facing the front of the house. Background The house was constructed in 1994. Mr. Smith purchased it in September 1997, and is the second owner. Soon after assuming ownership, Mr. Smith noticed and reported several structural defects to ABC Homes, Inc. ABC Homes hired Joel Watts of Watts Engineering to investigate Mr. Smith’s concerns. Mr. Watts noted several structural defects (see Watts letter dated February 20, 1998). They included the following: separation cracks between the walls and ceilings on the second level a ridge in the floor of the study a sag in the wall between the dinette and bathroom due to inadequate wood supports under the wall a sag in the left stairway wall The only defect that ABC Homes addressed was the sag in the left stairway wall. Structural repairs were made to the supports under the wall in accordance with a repair plan provided by Mr. Watts. These repairs were not done correctly. | Top | Table of Contents | DESCRIPTION OF THE PROPERTY Building Type: Two-story with gable roof and cathedral ceilings. Approximately 1500 sq. ft. plus a one-car attached garage. Site: The lot slopes at about a 15% slope from the street to the front of the house, then pitches off sharply toward the rear. Because the ground slopes toward the house in the front, It is possible for surface water to accumulate against the foundation wall between the front entrance and garage and seep into the soil. There is good pitch away from the house on the other elevations. Foundation: The house sits on a crawlspace. The interior part of the house is supported on four masonry piers. The exterior walls are supported on 8"" concrete block walls. There is also a 6' high cripple wall on the rear elevation to accommodate the sloping site. The garage floor is poured concrete. It is unknown whether it is a slab-on-grade or reinforced slab supported on the exterior walls and/or interior piers. Superstructure Framing: Wood studs, 2 x 10 floor joists, and roof trusses. The trusses consist of seventeen modified scissor trusses that span 26'. They are supported on the front and rear exterior walls only. Roof Covering : Asphalt Shingles. Exterior Wall Cladding: Vinyl siding. Interior: Interior walls and ceilings are sheetrock. The floors are covered with carpet and sheet vinyl. Method of Investigation Mr. Smith provided me with a set of construction plans for the house and the Watts Engineering letter, which I reviewed before visiting the site. At the beginning of the site visit, I interview Mr. Smith about the history of the problems. In the company of Mr. Smith, I then inspected and photographed the interior of the house, focusing most of my attention on the separation cracks in the second floor ceilings and the sloping floor in the study. Mr. Smith and I then walked around the exterior of the house and went into the crawl space where I inspected and photographed the masonry foundation and wood supports in the crawl space. As a final step, I inspected the garage. Back at my office, I reviewed the ABC Homes homeowner’s warranty and performed structural calculations on the foundation cripple wall and one of the girder supports. | Top | Table of Contents | FIELD OBSERVATIONS There are separation cracks between the walls and ceilings in the upstairs hall and study (Photo 2). The cracks are 1/4"" - 1/2"" wide. In addition, the sheetrock tape angles upward about 1/2"" at the joint between the walls and ceilings in several places in these rooms. Mr. Smith indicated that the cracks widen in the winter and close up in the summer. There is a noticeable ridge (hump) in the middle of the floor in the study, and the floor seems to slope toward the bathroom. Other than in this room, the floors on the first and second levels are level, and do not have excessive springiness. I did not observe any diagonal cracks at doorframes or other openings in the walls. I also operated several doors and did not observe any that bind in their frames. I noted two or three places on the first floor where there are hairline horizontal cracks in the walls. I attributed these cracks to thermal expansion and contraction of the sheetrock. I did not observe any cracks or other signs of settlement in the house foundation walls or piers. There is a shrinkage crack in the concrete floor slab in the garage between the chimney and entrance door, but no settlement cracks in the slab. The crawlspace is generally dry with good headroom and ventilation. The ground is covered with crushed stone and a polyethylene vapor barrier. I did not observe any problems with shrinkage and expansion of the clay soil around the footings due to excessive moisture in the ground. The 2 x 4 cripple foundation wall has no lateral bracing except for Celotex sheathing on the exterior side (Photo 3). Some of the 2 x 4 studs are twisted slightly, indicating that they are overstressed. There is an isolated masonry pier under the left stairway wall, below the end of the microlam beam that supports part of the second floor. The pier is not centered under the girder. In addition, it is not tight against the girder (Photo 8). Despite the lack of support, the girder does not appear to be under stress or deflecting excessively. The double 2 x 10 joists under the wall between the dinette and bathroom have been severely cut to allow installation of the toilet drain (Photo 5). The joists have been weakened so much that the support is now equivalent to half the strength of a single joist. The frame-out for the pipe chase under the first floor bathroom was inadequately constructed when the house was built, and it was not repaired properly when Mr. Smith complained about it. The joists on either side of the pipe chase have been sistered with joists that do not extend from support to support. In addition, the joist hangers at the headers are loose, causing the headers to slip out of position. Consequently, the bathroom floor and wall between the bathroom and dinette are weakly supported. | Top | Table of Contents | FINDINGS AND CONCLUSIONS The separation cracks between the walls and ceilings are probably caused by seasonal movement of the roof trusses. During the winter, the top chords pick up moisture and expand. As the top chords expand, they arch and pull up the bottom chords. In turn, this causes cracks to develop between the walls and the ceiling which is nailed to the bottom chords. In appendix B, I have included reference material on how to correct the problem. In my opinion, the ridge in the study floor is caused by two factors. First, there is no bearing wall below the wall between the study and bathroom. According to the construction plans, the wall is supported on double floor joists. The double joists may not provide enough additional support to prevent the floor joists from sagging. In addition, the weight of the bathroom fixtures may be contributing to the deflection. The ridge in the floor may also be exacerbated by camber in the joists, as explained in Joel Wattsís letter. The absence of cracks in the interior walls and foundation is an indication that the house is not settling. In addition, I did not observe excessive moisture in the ground anywhere around the foundation or evidence that the foundation or piers were being displaced or moved about by expansion and contraction of the clay soil. I performed an analysis of the 2 x 4 cripple wall to determine if it is capable of supporting the rear wall of the house under all load conditions. I calculated that the load on the wall could get as high as 1170 lbs. per ft. under conditions where there is a snow load coupled with heavy live loads on the floors. According to my calculations, the wall is only capable of supporting 990 lbs. per ft. The calculations indicate that lateral bracing in the form of 2 x 4 blocking should be added to the wall at mid-height to keep the studs from twisting or bowing. See Appendix D for the analysis. I also performed an analysis to determine whether the girder under the left stairway wall needs the support of the isolated pier. I determined that the induced bending stress on the girder is 1274 psi, the induced shear stress is 85 psi, and the induced deflection (sag) is 0.55"". The allowed stresses are 1200 psi and 90 psi, respectively. The allowable deflection is 0.47"". My interpretation of the analysis is that the pier is optional. One advantage of installing a new pier is that deflection can be reduced to near zero. I do not remember that deflection was a problem, however. See Appendix C for the analysis. The 2 x 10 joists that were cut to allow room for the toilet drain can no longer support the wall between the bathroom and dinette. More serious structural problems are apt to result if this problem is not fixed in a timely manner. The same is true of the frame-out for the pipe chase under the bathroom. The repairs that were made are totally inadequate and further structural problems could develop if this defect is not repaired in a timely manner. | Top | Table of Contents | RECOMMENDATIONS Remove the ceiling in the upstairs hall and other upstairs areas and refasten it to the trusses in a way that allows the trusses to move up and down without cracking the sheetrock. See method of repair described in Appendix B. The slope and ridge in the upstairs study can only be repaired by major structural work to strengthen and adjust the floor supports under this floor area. The unevenness in the floor surface may not be serious enough to warrant the high costs of making these repairs. The 2 x 4 cripple wall should be strengthened by installing additional lateral bracing. The existing isolated pier should be demolished and a new one installed under the girder. The girder should be jacked up to a level condition. Care must be used to prevent the jacking operations from causing cracks in the walls above. (This recommendation is optional, if the present floor conditions are acceptable). New 2 x 10 joists should be installed to support the wall between the bathroom and dinette. The frame-out for the pipe chase under the first floor bathroom should be completely redone. | Top | Table of Contents | ESTIMATED REPAIR COSTS Item Cost Demolish existing ceiling in upstairs hall. Reinstall new ceiling. $1,000.00 Repair the ridge in the study floor. $2,000.00 Brace the cripple wall. $200.00 Demolish the existing pier and install a new one under the girder. $1,500.00 Install new 2 x 10 joists under the bathroom wall. $500.00 Rebuild frame-out at pipe chase. $500.00 Total Cost $5,700.00 | Top | Table of Contents | LIMITATIONS The observations described in the report are valid on the date of the investigation and have been made under the conditions noted in the report. We prepared the report for the exclusive use of Mr. Smith and his successors and assignees. Criterium-Stanton Engineers does not intend any other individual or party to rely upon the report without our express written consent. If another individual or party relies on the report, they shall indemnify and hold Criterium-Stanton Engineers harmless for any damages, losses, or expenses they may incur as a result of its use. The report is limited to the visual observations we made during our inspection. We did not remove surface materials, furnishings or equipment, undertake any digging or excavation, or perform any destructive or invasive testing. Accordingly, we cannot comment on the condition of systems and components that we could not see. In addition, we are not responsible for conditions that were not within the scope of our services at the time of inspection. We did not assess the stability of the building or the underlying foundation soil since this effort would require excavation and destructive testing. We did not perform any computations or engineering analysis as part of this evaluation, nor did we conduct a comprehensive code review. This report should not be considered a warranty of condition, and no warranty is implied. The costs that we have given to remedy deficiencies are estimates only. They are based on our general knowledge of building systems and the construction industry. When appropriate, we have relied on standard references, such as R.S. Means Building Construction Cost Data. For items for which no standard guide exists (e.g., structural repairs), we have used our own cost records. Costs may vary significantly from estimates and competitive quotations from repair contractors. | Top | Table of Contents | William A. Stanton, P.E. | Top | Table of Contents | | Structural Inspections | Residential & Commercial Services |