Balcony is always having flooding issue when it rains heavily and it will cause leaking issues. Thus, waterproofing is needed.

Roof is the most needed for waterproofing as it is greatly expose to wind and wet weather.

Same as roof, garage roof also need waterproofing. People always think that Garage Roof is not needed for waterproofing however, it is also expose to wet weather where water leaking may happen if not protected by waterproofing products.