Because the materials of that era decide where fluids go. Carpet sits over pad that absorbs and hides; laminate floats over underlayment that wicks at every seam; particle board subfloor swells and holds. A 1988 assembly can carry contamination well below a surface that looks contained, which is why the assessment reads depth, with the surface lifted at an edge where needed, rather than pricing the visible area. Newer sealed assemblies sometimes scope smaller than they look. Yours will scope exactly as deep as it is, and the written estimate should show the reading behind the number.
Prefer to talk later? Leave your details and an independent local pro will call you back. No charge to you, no obligation.
Purgatory Creek Biohazard Cleanup is a free referral service. Submitting this form connects you with independent local contractors who provide the work.