Garage Foundation Wall Cracks and Leans Outward GENERAL INFORMATION Date and Time of Fact-Finding Inspection: April 10, 2001 @ 10:00 a.m. Weather Conditions: Sunny, 75° Name of Homeowner(s): Julie Anderson When did the condition(s) first occur? Ms. Anderson told me that the home inspector who inspected the home at the time she purchased it pointed out the crack to her. She said it was a hairline crack at that time. She said that the home inspector recommended that she monitor it. | Top | Table of Contents | BACKGROUND The house was constructed about 5 years ago. A vertical crack developed in the right rear corner of the garage foundation wall. When Ms. Anderson purchased the house 1½ years ago, apparently the crack was barely visible. The crack is now very visible (Photo 3). There is a thick coat of mortar parging around the crack. This is an indication that the crack has been patched one or more times by the previous owner or contractor during construction. | Top | Table of Contents | DESCRIPTION OF THE PROPERTY All directions in the discussion that follows are in relation to a person facing the front of the house. The house is a wood-framed, two-story structure, approximately 2000 sq. ft. in size (Photo 1). It has a two-car attached garage and crawlspace foundation. The back and sides of the house are clad with vinyl siding. The front is clad with vinyl and brick veneer. The ground in front of the house pitches moderately toward the street. The ground on the sides drops about 4' in the width of the house and continues to pitch off toward the rear. The foundation wall around the garage is constructed with 8"" x 16"" concrete blocks. The wall has been coated with a thin coating of cement to hide the joints in the blocks. The wall height varies from 1' high in the front to 4' high in the rear. The height of the fill behind the wall is about 5', since the footing is about 1' below the outside ground elevation. The garage floor consists of a slab-on-grade. The depth of fill under the slab varies from 1' in the front to 5' in the rear. The garage foundation walls contain the fill as well as support the stud walls. | Top | Table of Contents | METHOD OF INVESTIGATION At the beginning of my investigation, I interviewed Ms. Anderson about the history and location of the reported conditions. I then inspected the exterior and interior of the garage, focusing most of my attention on the crack in the foundation wall. After returning to my office, I researched the North Carolina Residential Building Code for the requirements for constructing masonry foundation walls. | Top | Table of Contents | OBSERVATIONS There is a vertical crack in the right rear corner of the garage foundation wall. The crack is on the right wall (Photo 2). It varies in width from 1/16"" wide at the ground to 1/4"" at the top of the wall (Photo 4). The crack has been patched as evidenced by the extra heavy coat of cement parging on either side of the crack. The parging masks the actual crack width. Probably the actual width at the top of the wall is about 3/8""-1/2"". The crack was caused by outward rotation of the rear wall at the corner. There is also a lip on the edge of the crack (Photo 3). The lip is 3/16"" wide at the top of the crack and peters out at the ground. The parging masks the width of the gap. Probably the actual width of the lip is º"". The lip was caused by outward rotation of the sidewall at the corner. There are no cracks in the right rear corner of the garage floor slab (Photo 5). In addition, there are no cracks in the top of concrete block foundation wall at this location. This is an indication that the corner of the garage is not settling. There are small gaps between the slab and foundation wall, however. The gaps correspond somewhat to the outward movements that have occurred in the foundation walls I did not observe any problems with the way the exterior door operates. The door is located about 15-20' from corner of the garage. | Top | Table of Contents | FINDINGS AND CONCLUSIONS The crack in the garage foundation wall was caused by the concrete blocks separating at the corner. The earth pressure and weight of the garage floor slab and car has pushed the side and rear walls outward. The crack probably would not have occurred if the foundation wall had been reinforced properly. The North Carolina Residential Building Code requires that vertical reinforcement be used in 8"" hollow block walls when the height of the unbalanced fill exceeds 4'. It also requires that intersecting masonry walls be anchored with joint reinforcement at intervals not exceeding 8"" and extending 30"" in each direction. It is hard to predict if the corner will continue to separate more. The movement may have stabilized or the constant pressure on the walls may cause further movement. At present, the structural integrity of the foundation wall has not been materially compromised. Further outward movement could become a structural problem, however. It would be prudent to be proactive and repair the corner of the wall now before the condition gets worse. | Top | Table of Contents | LIMITATIONS The observations described in the report are valid on the date of the investigation and were made under the conditions noted in the report. We prepared the report for the exclusive use of AIC and their 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. | Top | Table of Contents | William A. Stanton, P.E. | Top | Table of Contents | | Structural Inspections | Residential & Commercial Services |