Munds Park Foundation Investigation 12.7.2021
Challenge
The Owners of this 1979 single-family home reached out to us after noticing signs of a foundation issue. These signs included:
-Interior wall cracks
-Bowing walls
-Sagging floors
A Level A Foundation Inspection determined a Level B Foundation Investigation was needed to determine if the symptoms (also known as signs of stress) are the result of foundation movement and if a foundation repair is needed.
Homeowner’s Concerns/Goals: The homeowner is primarily concerned with the areas of settlement that may or may not have been caused by a water leak. The homeowner would like to address any foundation issues and remodel the home.
Home details: 1979 Crawl Space + Block Stem Wall with Rebar. Top of Footing: 16” Below Grade
Introduction: Thank you for allowing Arizona Foundation Solutions to present this foundation survey and assessment for the proposed foundation repairs on your property.
Purpose of the Investigation: The purpose of this report is to evaluate the foundation and the foundation conditions of this property, and to perform a manometer and foundation survey on the interior of the property.
Limitations: The purpose of this report is limited to documenting and addressing the areas of concern indicated by the customer related to potential foundation movements. Arizona Foundation Solutions uses a variety of tools such as manometer survey, observations by technicians with notes and photographs, and industry standards such as the Foundation Performance Association (FPA) “Guidelines for the Evaluation of Foundation Movement for Residential and Other Low-Rise Buildings” to determine if foundation movement has impacted the serviceability of the home. The term serviceability relates to items such as pinched doors and windows, cracks in drywall and slabs, cracks in exterior stucco and walls, and the like. Recommendations in this report are made to address and limit future issues related to serviceability and the customer’s concern.
The extent and scope of this manometer and foundation survey and assessment are detailed as follows:
• Perform a manometer survey.
• Locate areas of potential foundation and floor movement, if any.
• Visually inspect and record the interior and the exterior of the location.
• Evaluate any noted movement using industry consensus methods, if any.
• Prepare a documented repair plan if needed.
Foundation Footprint: A drawing of the footprint of the first floor was created and is included in this report.
Exterior Inspection: The exterior of the location was visually inspected. Items such as foundation cracks, exterior wall cracks, improper grading, type of structure, poor drainage, gutters or no gutters, bowed retaining walls, large trees close to the foundation, and any type of obstructions that may or may not influence the repair process were noted and recorded.
Interior Inspection: The interior of the location was visually inspected. Items such as floor cracks, wall cracks, ceiling cracks, sloping floors, uneven countertops, doors and windows that are out of alignment, cracked window glass, and bowed walls were noted and recorded.
Manometer Survey: The manometer survey, also known as a floor survey, is a measurement of the differences in interior floor elevations. The flatness of the interior floor was measured using a highly accurate survey device known as a Manometer. The entire interior floor area was surveyed, and the elevations were recorded. These data points were then entered into a computer program that provides a topographical map showing the high and low elevation contours of the floor surface. This topographical map shows where the foundation is no longer level and shows where support and stabilization are needed. The floor survey also demonstrates whether any floor slab heave or settlement exists.
After examining the home and performing the manometer survey, Arizona Foundation Solutions believes the home could be experiencing foundation settlement in the central, east, and northeast portions of the home as shown by the damage (also known Signs of Stress) and lower readings on the Topographical 2D Map. The drop-off in floor elevations on the topographical map is consistent with a foundation settlement pattern. Settlement can be caused by one or any combination of many factors including sub-grade saturation of moisture due to poor drainage, years of storm runoff, plumbing leaks, improper compaction, the lack of a proper foundation system, and/or (in most cases) natural earth movement. The reported pipe leak may have contributed to worsening the indicators that suggest the home could be experiencing foundation settlement.
Solution
After examining the home and performing the manometer survey, Arizona Foundation Solutions believes the home could be experiencing foundation settlement.
Arizona Foundation Solutions believes that the proper way to permanently stop the perimeter foundation settlement is to underpin the areas that are experiencing movement. Underpinning is the process of installing deep foundation elements called piles. Piles are engineered foundation supports that are driven down past the unstable soils and are then locked up into load-bearing strata, which can support the loads that are transferred to them. Once the piles have been installed, they can be used to lift the perimeter foundation up to its Highest Practical Maximum. The piles should be spaced approximately six feet on center and should start and stop near the hinge points of movement (exact spacing to be determined after load-bearing calculations). In this case, the piles would be located in the north, east, and western portions of the home.
AZFS believes the best way to stabilize the support beams in the crawl space is with Smart Jacks. These are adjustable galvanized supports engineered to be placed under the sagging floors to help prevent settlement of the floor joist system. The Smart Jack sequence should start at approximately 2’ off each perimeter wall and should not be spaced more than 7’ on center (exact spacing to be determined after load-bearing calculations). An engineered push pier will be driven concentrically beneath the beam at each Smart Jack location to provide a footing for each Smart Jack. If for whatever reason the installation of concentric piers is not possible, a concrete footing of engineered size will be poured beneath the Smart Jack to distribute the load. The Smart Jacks will then be cut to size and set in place. Finally, the units will be adjusted to lift the sagging floors back to their best functioning point or the Highest Practical Maximum.
This crawl space plan addresses foundation support. Carpentry and non-soil-related movement are outside the scope of work of this project.
It is also beneficial to manage the moisture around your home using conventional means as outlined below:
• Hire a reputable plumbing leak detector and repair service to check both pressure and sewer lines, this is usually done for less than $500. If repairs are needed, they are usually not expensive.
• Make sure the grading of the terrain is sloped downwards at a 5% slope from the home at all areas of the perimeter.
• Stop irrigating plants that are near the foundation and make sure there is nothing trapping the moisture from flowing away from the home.
• When permanently stabilizing, lifting, and/or mitigating a foundation movement problem, AZFS recommends waiting AT LEAST 6 months before investing in cosmetic repairs.
Safety or Structural Concerns: None
