How are other inspectors addressing efflorescence in crawlspaces? It’s very common in the southeast and I’m not sure how to note on it in my reporting. I see it in almost every crawlspace and it’s always on the blocks that are below grade, so it makes sense because those below-grade blocks are in contact with moist soil. Not sure how to address it or if I should address it. Please advise.
You do not “address” it, you report the presence of it, more as an informational narrative than a statement of defect, and I typically do not go beyond the following…
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Excellent, thank you for the advice!
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Also take into account the causes of this and moisture:
Gutters
Site Grade
Grade against the foundation
Ventilation
Hose valves
HVAC condensate
Roof too big for the gutter system
Discuss anything you see associated with moisture.
You do not need to discuss anything below grade.
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Many times, efflorescence is an indicator of other issues or concerns with the building and performance. When you see it, try to assess what is happening. If its just a very concentrated small amount that is on a very small area of the CMU block foundation wall near/at or in contact with the soil on a 40 year old home, then probably not an issue and wouldn’t make it in my report. If its widespread in a crawlspace on 1 or more foundation walls and I can see evidence of moisture seepage coming out through the CMU block/mortar, that would make it in a report. If I can see it widespread in a crawlspace on the foundation walls with no other visible moisture intrusion issues but the crawlspace feels damp (high RH%) and the soil is saturated, then that would make it in a report. Also, if I’m seeing widespread efflorescence in the crawlspace on the foundation walls, I’m on higher alert. I’m probably going to find several other issues that need to be addressed and documented in the report.
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CMUs are prone to water penetration. Fact of life. Mention presence of efflorescence and move on.
Cheers
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I am similar to Jeffrey…
Moisture stains: Efflorescence noted (indicates past moisture) Area is currently dry
Moisture stains do not automatically indicate a concern, but the source of the water should be determined if possible and corrected. Two common sources of moisture stains and efflorescence are sub-surface water and surface water that can drain down next to the foundation. Inadequate management of surface water is the most common source of water intrusion and inspector’s comments in Section 3 are important. Controlling both sources of water may require remedial action such as; landscaping changes, and/or a perimeter drain system and sump pump.
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I did not elaborate further due to the OP’s statement in his post. It seemed to me he has a handle on the situation relating to causation.
Thank you everyone, excellent information. I appreciate the verbiage as well, certainly something I’ll use in future reports.
Here is what AI says for what it’s worth.
Moisture is one of the most significant factors affecting the longevity and structural integrity of masonry block walls. Here’s how it impacts their lifespan:
Freeze-Thaw Damage
When water penetrates masonry blocks and freezes, it expands by about 9%, creating internal pressure that can crack or spall the blocks. This cycle of freezing and thawing, especially in climates with temperature fluctuations around the freezing point, gradually weakens the masonry and creates larger cracks that allow more water infiltration.
Efflorescence
Moisture dissolves salts naturally present in masonry materials and mortar. As water evaporates from the surface, these salts crystallize and form white, chalky deposits called efflorescence. While primarily aesthetic, severe efflorescence can indicate ongoing moisture problems and may contribute to surface deterioration.
Mortar Joint Deterioration
Mortar joints are typically more porous than the blocks themselves, making them the primary pathway for water infiltration. Constant wetting and drying cycles cause mortar to soften, crack, and eventually crumble, compromising the wall’s structural integrity and allowing more water penetration.
Structural Weakening
Prolonged moisture exposure can reduce the compressive strength of masonry blocks, particularly those made from concrete or clay. The blocks may become more friable and prone to cracking under load.
Mold and Biological Growth
Persistent moisture creates conditions for mold, algae, and moss growth, which can stain the wall and contribute to surface deterioration. Plant roots from vegetation growing in cracks can also cause mechanical damage.
Prevention and Mitigation
Proper drainage, waterproofing, quality mortar joints, and regular maintenance significantly extend masonry wall life. Well-maintained masonry walls can last 50-100 years or more, while those exposed to chronic moisture problems may require major repairs within 20-30 years.
The key is controlling moisture at the source through proper design, construction details, and ongoing maintenance rather than trying to address problems after they develop.