Thin film, water-based intumescent coatings

Used mainly for 30 to 120 minute fire rating levels (FRLs)

Positives

• Best done onsite.
• Low VOC.
• Can achieve high levels of finish.
• Can be top coated.

Negatives

• This method is hard to do offsite due to its low levels of tolerance to water ponding or pooling during construction.
• Cannot handle extended periods of environmental exposure.
• For higher FRLs (90 to 120 minute) this method usually requires between 1.3mm and 6mm of coating. This needs to be done in multiple coats which is very slow and risky for the main contractor and subcontractor.

• High film build 2mm plus if overcoated too quickly - the coating is prone to blistering and, in some cases, delamination.