The Difference Between A Floor Stain and an Active Leak

Subfloor Stain
Subfloor Stain

Sometimes spots on a floor, subfloor, or attic can scare homeowners and would-be homeowners. However, the difference between an old floor “stain” and a “leak” is pretty simple: a leak is active, while a stain shows that a leak happened sometime in the past. So, if we don’t know the home’s history, how can we test for that?

Generally, there are three ways to check if a stain has active moisture, but the final one is more conclusive that the others:

  1. Smell: Often active moisture brings with it a mildewy or humid smell. In a crawlspace, however, it can be hard to tell.
  2. Touch: If the area is accessible, touching the spot can help determine if there is active moisture. In a crawlspace that is already somewhat damp, however, hands can already feel wet.
  3. Moisture Test: we use moisture testing in cases like this to finally tell the difference between an (old) stain and active moisture. The stain pictured above was just that: a stain, but only the moisture test could tell us for sure that it was not currently active.

In the end, we use moisture testing to determine what may a be a big problem (an active leak) and a just smaller, older stain. It helps to know the difference.