Drying in place versus replacing
Dry or clean in place
- Small wet areas near a single leak or head
- Clean-water source caught quickly
- Facing intact, not torn or delaminated
- No smoke odor in the insulation
- Can be dried with air movement once trapped water is drained
Remove and replace
- Large saturated areas or pockets that held water for days
- Facing torn, mildewed or stained through
- Smoke odor absorbed into the fiberglass
- Contaminated water such as backed-up drains
- Roof panels being replaced anyway after hail or wind
Why this insulation is tricky
In a typical pre-engineered building, rolls of faced fiberglass run across the purlins with the panels screwed down on top, compressing the blanket at each purlin. The facing is meant to face the warm side, slowing moisture from inside air reaching the cold metal. When water gets in from a roof leak or a sprinkler break overhead, it lands on top of that facing and has nowhere to go. It collects into sagging bellies that can hold a surprising weight of water and then tear or spill all at once.
Drying insulation in place is possible for small areas, but water trapped between the facing and the roof panel dries slowly because the facing blocks airflow and the panel above is sealed. Over time, damp fiberglass loses insulating value and the facing can grow mildew. In a building that sees cold winters, wet insulation also adds to condensation problems on the underside of the roof.
Smoke is a separate problem. Fiberglass is porous and holds odor. Cleaning the facing may improve its appearance without removing the smell, and many facilities find that odor returns on warm days when the roof heats up. Insulation directly above a fire area is commonly replaced.
Replacing insulation in an existing building usually means working from inside on lifts with a liner system or from the roof when panels come off. Coordinate with the roofer so the work is done once.
Quick sorting
- IfYou see sagging pockets of waterThenKeep people and equipment clear, then have them drained in a controlled way by someone on a lift, catching the water.
- IfThe area is small and the facing looks clean after drainingThenAsk about drying in place with monitoring, and recheck for staining or odor after a few weeks.
- IfThe area is large or wet for several daysThenExpect replacement; ask for photos and measurements of the affected area for the claim.
- IfSmoke odor is present in the insulationThenAsk whether cleaning has been tested on a sample before agreeing to it; replacement is often more reliable.
General information for Commerce City, not a quote or professional advice. In an emergency, call 911.