what is low modulus silicone
High & Low Modulus. Sometimes silicone sealants are described as 'High modulus', or 'Low Modulus'. The low modulus products are more elastic and well suited to sealing tasks that need to accommodate more movement without failing.ilicone sealant is a versatile and flexible waterproof sealant with a multitude of applications (see the Putty & Mastic article for other types of sealer). It is particularly good in situations where you need to make a waterproof gap seal, but cannot completely eliminate movement between the parts to be sealed.