The phases of renew joint sealing are as follows:
(if building is new start phase 2.)

1. Taking off all the broken old sealant and the backer rod.
2. Grinding the gripping surfaces of sealants.
3. Cleaning the gripping surfaces of sealants
4. Insulation and ventilation space check behind the backer rod. Adding or removing the insulation if necessary. Insulation and ventilation are both needed.
5. Installing water-resistant backer rod with suitable size in the right depth.
6. Installing the suitable primer to the gripping surfaces of the joint.
7. Installing ventilation tubes or boxes according to the working plan.
8. Installing the suitable sealant in the right depth.
9. Levelling the sealant with a suitable tool.