Sealants, Or Pre-Fabricated?

The normal installation methods are either field-applied sealant, or a pre-fabricated movement joint profile.

And which is better depends very much on the application. While sealant-type methods are suitable for most applications - and indeed, is the only method in some - a straight analysis of the two methods does identify a weakness in the sealant-type joints. 

Silicone Expansion Joint
No edge protection
Retains memory
Requires maintenance
Two-step installation 

Pre-fabricated expansion joint profiles
Edge protection
High elasticity
Maintenance-free
One-step installation
Straight uniform joint
Prevents sound transmission
Long-lasting professional installation 

Figure 1 shows where the differential movement between the floor and wall has resulted in a torn silicone sealant joint. This also shows what is meant by "retains memory," where the sealant used has stuck to the surface with which it has the better bond - either the wall or the floor. 

This type of damage is particularly common where a floating floor has been used, such as a heated screed, or timber.  The damage seen here needs expensive remedial action, with the removal and cleaning of the damaged areas followed by the re-application of the sealant, which may fail again. 

The problem is more acute in areas with high hygiene requirements, such as hospitals, food preparation areas, and leisure facilities. And, of course, if waterproofing was reliant on the sealant joint, that, too would have failed. 

But the performance of a pre-fabricated joint profile in the same situation, would be very different.