Deficiency Identification Guide

Describing a cleaning deficiency accurately is more useful than describing it forcefully. "Striping across the north walkway, consistent with wand passes at varying standoff" tells a contractor what to fix and how. "It looks terrible" starts a conversation about taste.

This guide covers the common defects on commercial exterior work: how to recognize each, what typically causes it, and whether it is correctable.

Coverage and Uniformity Defects

Substrate Damage

These are the serious ones, because most are not correctable by cleaning and some are not correctable at all.

• Etching or surface erosion — a visibly roughened or eroded track, often following the nozzle path. Caused by excessive pressure or too close a standoff. Not correctable; the material is gone.
• Sealer or coating removal — an area that now absorbs water and stains where it previously repelled them. Caused by aggressive pressure or incompatible chemistry. Requires resealing or recoating.
• Clouded or etched glazing — hazing that does not wipe off. Caused by incompatible chemistry contact. Generally requires replacement.
• Mortar or grout loss — recessed or washed-out joints on masonry. Caused by excessive pressure on aged or soft mortar. Requires repointing.
• Coating damage — blistering, peeling, or exposed substrate. Caused by pressure or chemistry on a coating at end of life. Requires recoating.
• Raveling on asphalt — loosened surface aggregate. Caused by excessive pressure on aged or oxidized asphalt. Not correctable by cleaning.

See surface damage risks and how to avoid them.

Delayed-Onset Defects

The most consequential failures are not visible at the walkthrough. Recognizing the later indicators matters because the pre-work condition record is what settles them.

• Interior staining on a wall or ceiling adjacent to a washed elevation, appearing days or weeks later — suggests water entered the assembly.
• Finish blistering or delamination weeks after cleaning — suggests trapped moisture behind the coating.
• New absorbency — a surface beginning to take stains it previously repelled, indicating sealer loss.
• New efflorescence on a wall that did not previously show it — suggests a new moisture path.

None of these prove causation, and all have alternative explanations. Where they appear within a few months of cleaning, the pre-work photographic record is the most valuable document available.

Conditions That Are Not Deficiencies

Equally important is recognizing what is not a defect, because pursuing these damages the working relationship and wastes the property's leverage on real items.

• Residual discoloration on a surface categorized "will lighten" in advance.
• Permanent conditions — etching, chemical alteration, long-established staining in porous substrate — documented as exclusions before the work.
• Pre-existing damage revealed by cleaning. Soiling conceals cracks, patches, and prior repairs; removing it does not cause them.
• Normal resoiling between the work and a late walkthrough.
• Differences between substrates that were never going to match.

Describing a Deficiency Usefully

1. Name the defect using the terms above where they apply.
2. Locate it precisely — row, bay, elevation, storefront number.
3. Photograph it, at a low angle for uniformity defects.
4. State the expectation — usually "to match the approved test area."
5. Say whether you believe it is correctable, which frames the conversation as remedy rather than blame.
6. Reference the scope clause it falls under, if there is one.