FAQ: Construction Sealant Time to Performance Test

The length of cure needed for a one-part room temperature vulcanizing (RTV) moisture cure silicone sealant in performance testing has several variables, including the type of test.

One-part DOWSIL™ Structural Sealants or Weatherseal can go through static water testing after 24 hours (48 hours in colder or dryer environments) if the assembly is not pressurized or put under movement. The test is similar to being exposed to a mild rain shower, after being installed, where the sealant does not experience significant stresses.

For structural load testing or other dynamic testing where the sealant may see significant loading events, the sealant should be fully cured and adhered prior to testing. Full cure typically will be achieved between 7 to 21+ days and is dependent on temperature, humidity, sealant thickness and bite.

The larger the joint dimension, the longer it will take the sealant to cure. A 12” (30,5 cm) mini mock-up sample can be made and destructively tested to determine when complete cure and adhesion has developed. Uncured or partially cured sealants should not be subjected to joint movement, which could induce premature failure in the sealant.