laitance
Very lowTechnical/Professional
Definition
Meaning
A milky, scummy deposit of fine particles that appears on the surface of freshly poured concrete or cement as excess water rises and evaporates.
In broader technical contexts, can refer to any milky surface deposit or efflorescence on building materials, or metaphorically to something superficial or insubstantial that forms on a surface.
Linguistics
Semantic Notes
The term is highly specific to construction, civil engineering, and materials science. It denotes a defect or byproduct of the curing process, not a desired component. Its use outside these fields is extremely rare and likely metaphorical.
Dialectal Variation
British vs American Usage
Differences
No significant difference in meaning or usage. The term is used identically in both UK and US technical English within the construction industry.
Connotations
Universally negative in technical contexts, indicating poor surface quality or improper mix/curing.
Frequency
Equally rare and specialized in both varieties. Known primarily to professionals in concrete work, masonry, and related trades.
Vocabulary
Collocations
Grammar
Valency Patterns
The [material] exhibited laitance.Laitance formed on the surface.To remove the laitance before [next step].Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “None”
Usage
Context Usage
Business
Virtually never used.
Academic
Used in papers and textbooks on concrete technology, materials science, and civil engineering.
Everyday
Extremely unlikely to be encountered or used.
Technical
Primary context. Used in specifications, site reports, and technical manuals discussing concrete finishing, surface preparation, or defects.
Examples
By CEFR Level
- The builders had to clean the white powder from the new floor.
- Before applying the floor coating, the contractor removed the laitance from the concrete slab with a grinder.
- The presence of significant laitance indicated that the water-cement ratio had been too high, compromising the surface durability and requiring mechanical abrasion prior to the application of the resin topping.
Learning
Memory Aids
Mnemonic
Think of 'LAIT' (French for milk) + 'ANCE' (a state). Laitance is the milky state on new concrete.
Conceptual Metaphor
SURFACE IMPURITY IS SKIM / QUALITY DEFECT IS A FILM.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Do not confuse with "молочность" (milkiness) in an agricultural sense. The direct Russian technical equivalent is often "цементное молочко" or "высол" (though the latter is more general for efflorescence).
Common Mistakes
- Misspelling as 'laitence' or 'laytance'.
- Using it as a verb (e.g., 'The concrete laitanced').
- Confusing it with general 'dust' or 'grime'.
Practice
Quiz
In which industry is the term 'laitance' primarily used?
FAQ
Frequently Asked Questions
No, it is generally considered a defect indicating excess water or improper finishing, which can lead to a weak surface layer.
Yes, by using a correct water-cement ratio, proper curing techniques (not over-watering), and effective finishing (e.g., floating) to keep fines in the mix.
It is typically removed by mechanical methods such as grinding, sandblasting, or scabbling to expose a sound, aggregate-rich surface for bonding.
They are related but distinct. Laitance is a surface layer of cement and fines from the mix itself. Efflorescence is a crystalline salt deposit that migrates from within the material to the surface.