Restoration

What the IICRC S500 asks of your documentation

The S500 does not tell you a room is dry at a number. It tells you to establish what dry means in that building and then show that you got there.

It is a standard of care

The S500 is the water damage restoration industry’s consensus document, published and periodically revised by the IICRC. It describes the principles a competent restorer is expected to work to, and it is written as a standard of care rather than a set of fixed thresholds you can print on a card.

That framing matters for documentation. Because it does not hand you a universal "dry" number, what you are expected to produce is evidence: what the dry standard was in this building, what the affected materials read, and how those readings moved over the course of the job.

The dry standard is the whole trick

A moisture reading on its own is a number without a meaning. What makes it evidence is a comparison: the same material, same meter, same scale, somewhere in the same building that was not affected.

Establish that reading first, write it down, and use it as the target. "Wall reads 17%" says nothing. "Wall reads 17% against an unaffected dry standard of 9% on the same wall type" is an argument.

What a defensible drying log looks like

• The same points, marked and identified, on every visit — not "the north wall" on Monday and "by the window" on Thursday.
• The same meter and the same scale throughout. A log that switches between %MC and a relative scale cannot be drawn as a curve.
• A date and time on every reading.
• The dry standard recorded alongside, so every reading has something to be compared to.
• Ambient conditions where you take them — temperature and humidity affect what the numbers mean.

A log that satisfies all of that can be shown as a falling curve, and a falling curve is the single most persuasive object in a water file. A log that switches scales halfway cannot be drawn at all.

Trueline logs readings against the damage they belong to, keeps the scale with each reading, and refuses to draw a curve across a scale change — it lists them instead and says why. A curve drawn across two different scales is not a curve.

When drying stops

Not on a fixed day, and not when the equipment has been in for the number of days the estimate assumed. It stops when the affected materials reach the dry standard you established, and the log is what shows they did.

Questions people ask

What moisture content counts as dry?

There is no universal number, which is exactly why the standard asks you to establish a dry standard from unaffected material of the same type in the same building. That reading is the target, and the comparison is what makes your other readings mean anything.

How often should moisture readings be taken?

On every visit while equipment is in place, at the same identified points, with the same meter and scale. Consistency is worth more than frequency — a daily log that moves the points around proves less than a regular one that does not.

Do I need to buy the S500?

If you are doing this work commercially, yes. It is revised periodically, the detail matters, and adjusters who work to it will know which edition you are referring to. Summaries — including this page — are orientation, not the standard.

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Where this fits with Trueline

Trueline is an iPhone app that measures a room, takes it off, prices it from your own rate book and turns it into a proposal — with every length carrying whether it was scanned, drawn or measured, right onto the document a client reads. See how it works, or take the free templates and use them with whatever you already have.

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