What is a performance indicator?
A “performance indicator” is an irregularity in the house that may be the result of how the foundation is performing. When I say: may be the result of how the foundation is performing, what I mean is that the distress is consistent with one of the two recognized slab-on-ground distortion modes: namely center lift and edge lift.
What is a repair indicator?
A “repair indicator” is a condition or irregularity that indicates a structural safety or integrity issue.
Performance indicators can be found in the large majority of older homes. Repair indicators are not common and are a more serious structural issue.
It is possible for a performance indicator to turn into a repair indicator. Consider this example: one day there appears a hairline crack at the corner of a door opening. A hairline crack could be caused by a lot of things, but it certainly is not an indication that the house framing or the foundation has structural safety or integrity issues. In any case, it can be repaired without underpinning the foundation.
Now imagine that two months later that the hairline crack has grown to a width of two inches. This is another kettle of fish and should be a serious concern. The more general rule is that many performance indicators can become a repair indicator if they are severe enough.
TREC and TBPE guidelines
Both TREC and TBPE (Texas Board of Professional Engineers) have guidelines that address how TREC inspectors and TBPE engineers should make and report on foundation performance.
The TBPE has made it clear that if a complaint is filed against a Professional Engineer, they may judge the competence of the engineer by referring to a document titled: Guidelines for the Evaluation and Repair of Residential Foundations – Version 2 published by the Texas Section of the American Society of Civil Engineers (Tx Section-ASCE) contains a list of conditions or indications of adverse foundation performance.
The TREC Standards of Practice (TREC SOP) for home inspectors contains a similar list of performance indicators. This article looks at the performance indicators in the Texas Section ASCE guidelines and discusses each one in the hope that real estate agents and TREC inspectors will be better able to read and understand reports made by inspectors and Professional Engineers.
Both documents are guidelines. It is clear that the Tx Section ASCE guideline is a guideline. The guidelines inform the engineer or inspector what to look for when forming an opinion as to how well or poorly the foundation has performed in the past.
The guidelines make no effort to provide guidance concerning which indicators are more or less reliable. They also do not shed any light on how to make a diagnosis of what is the result of foundation distortion, especially excessive foundation distortion, or some other, more benign cause. TREC inspectors should not be making such a diagnosis. According to the Texas Board of Professional Engineers making such a diagnosis where expansive soils exist would be a violation of the Texas Engineering Practice Act.
Cracking or separating of exterior walls
Foundation distortion can pull the exterior cladding apart. Most vulnerable are brick veneer, stone veneer, and stucco. These materials are all relatively brittle. The cracks can be used to estimate how much a slab foundation has bent along a profile that follows the brick veneer wall.
If the exterior cladding is siding, there may not be much visible separation. There are at least two reasons for this: the siding material is more forgiving than brick veneer and it typically has more joints than brick veneer so that the separations are more widely distributed.
Are cracks and separations in brick veneer and siding reliable indicators of foundation distortion? In a word: yes.
Rotating, buckling, or deflecting masonry veneer panels
Some engineers are apparently concerned about brick veneer falling away from the stud frame wall. Every house that I have seen being bricked are held in place by using brick ties that secure the brick veneer to the stud frame.
Racking of concrete foundation elements
Slab-on-ground foundations have no concrete elements that are capable of racking.
Cracking of gypsum board walls and ceilings
Diagonal cracking in gypsum wallboard is normally a reliable indicator of foundation distortion. The corners of doorways and window openings are stress concentrations due to the geometry of such openings. The design methodology used virtually guarantees some degree of cracking at the corners of window and door openings.
I cannot say the same for cracks in ceiling wallboard. Ceiling cracks can be due overloading of the frame structure, poor fastening, age, etc. S common cause is where the framer braced the rafters by using struts that transfer to loads to the ceiling joists. In my experience, it is not normal for framing plans to not detail how rafters are to be braced. I have been told that many production builders do not include framing material when they take off what is needed to brace the rafters. The assumption is that the framer will make do with scrap material. Some times that works and sometimes it does not.
Separating walls from ceilings or floors
In my experience, this is rare, but, absent some obvious framing issue, it is certainly possible that the separations are a performance indicator.
Separating of rafters from a ridge board
This can be a serious structural issue, but foundation repair is normally not cost-effective. Anytime you see a gap between rafters and the ridge board the situation needs to be examined carefully. There are several facts that need to be kept in mind. First, is the house a single story home? Single story homes are more likely to experience this than two story homes. Second, you have to keep construction tolerances in mind. There are no official construction tolerances, but I see plus or minus 1/4 inch. If there is a quarter inch gap between the rafters and the ridge, there is no real to believe foundation distortion is the culprit.
Assuming that the house is more than, say, 20 years old, the rafters could shrink another quarter inch most of which is likely to be taken out be at the ridge. We now have 1/2 inch gaps with none of it attributed to foundation distortion.
Let me be clear: 1/2 inch is too large regardless of the cause. It should be repaired by scabbing the rafters, but unless the gaps were at least 3/4-inch, I would not normally not attribute the gaps to excessive foundation distortion.
Racking of door and window frames
Racked door frames are unquestionably reliable indicators of slab foundation performance.
Separating or racking of other structural framing
The only structural framing that is affected by foundation movement to any significant degree is wall framing. The wall framing is literally bolted to the slab foundation. The roof and ceiling framing is not directly connected to the slab and is thus insulated from foundation distortion to a degree that can not be said of wall framing.
Cracking, buckling or separating of floor coverings
The floor coverings that are most telling of foundation performance are floor tile and wood or wood product flooring. Carpet is not rigid and does not react in any perceptible way to foundation distortion.
Floor tile reacts to foundation distortion by cracking. Floor tile will crack with even minor foundation distortion. Foundation movement does not, however, cause floor tile to buckle. Loose and buckling tile is due to installation issues.
Separating of initially tight joints
This usually refers to joints in wood trim material. The most common of these joints at the joints at doors and windows. If the separations are within 1/16th to 1/8th inch they could be due to normal wood shrinkage. This is another situation that foundation repair cannot correct – initially tight joints can fill filled with caulk and repainted. If that is not good enough, the trim material can be removed and replaced with new material. This makes more sense than underpinning the foundation.
It might be objected that if the foundation continues to move the joint will simply open again. That ignores the fact that the warranties used by foundation repair companies do not – I repeat – do not, guarantee that initially tight joints will not reoccur.
Deflecting or tilting of structural elements
This seems to refer to elevated type foundations such as pier and beam foundations. I cannot see any application to slab-on-ground foundations.
This could be referring to corner or wedge cracks, exposed reinforcing steel including exposed rebar and cable ends and cable anchors. This calls for concrete repairs; not foundation repair in the sense of underpinning.
A final comment about performance indicators
A short comment from the Texas Section ASCE guideline that regarding foundation performance:
Observation of some of the listed conditions does not necessarily imply inadequate
structural performance or insufficient stiffness. The importance of any of these indications may depend upon the age of the structure and any previous repairs.
The way I interpret this is that there are two points to recognize here. First, no single performance indicator, nor any combination of performance indicators, dictates that foundation repair is necessary. Second, each indicator occurs in a context. The reliability of each of the indicators will change with the context meaning each house and situation.
What would be a repair indicator? Here is what the guidelines say:
If the residence is found to be unsafe due to structural inadequacies, the client and/or civil authorities should be informed immediately. The engineer should recommend repair, restoration, remediation, adjustment, or use alternatives if structural integrity is inadequate. The engineer should provide alternatives for the client’s consideration if performance is inadequate. Recommendations and alternatives should be commensurate with the nature and cause of the inadequacy, and the seriousness of its consequences.
The engineer should consider the cost-effectiveness and practicality of the
recommendations, the projected performance, and the needs of the client. For example, an owner may choose to perform periodic cosmetic repairs and door adjustments, rather than comprehensive foundation underpinning.
In other words…
If there are structural integrity issues that make the unsafe, the engineer should present the client with alternatives including such as repair (underpinning), restoration, remediation, adjustment or use alternatives. The cost-effectiveness and practicality of the recommendations, the projected improvement due to the recommendations and the needs of the client all need to be considered.
Consider the last portion of the last sentence as quoted below:
…an owner may choose to perform periodic cosmetic repairs and door adjustments, rather than comprehensive foundation underpinning.
It should go without saying that foundation repair is rarely cost-effective as compared to making periodic cosmetic repairs and door adjustments.