Case 1

Good Practices

Sealants

Design

Ensure that the sealant chosen is suitable and is able to perform under tropical conditions. Avoid installing new sealant over an existing one during maintenance operation. Certain types of sealant cannot bond with other sealant. For example, sealant other than silicone is rarely capable of providing durable bond to existing silicone. On the other hand, silicone often will not cure properly when installed over isobutylene.

Replace all failed sealant with better UV resistant quality sealant for use in local climate so as to accommodate the movement joints. Polysulphide sealant has good movement capacity, high chemical resistance, suitable for submerged application and a long service life. Other generic sealants are also acceptable, for example, silicone.

Good practices adopted to prevent water penetration must be initiated with the correct choice, application and maintenance of sealants.

Application

Quality control

It is advisable to carry out a weather performance test by constructing a mockup of the façade and performing water, air infiltration as well as wind loading tests in a test chamber so that the effectiveness and suitability of the sealants and façade components can be determined.

Quality of glazing workmanship. Site failures and conditions and the skills of the operators vary considerably. On-site glazing must conform to the architect’s specifications. Factory glazing has the advantages of being easier to control for quality of workmanship and of being carried out in a cleaner, dry atmosphere, without problems of access to the window frames.