What most common roof problems you have witnessed?

In my house I often come across the leakage of water and moisture. As we know with any roof, no matter what type it is we will have roof leaks. This is because of single-ply membrane roofs installed with poor seams. You need to have good seams with single-ply, because, the membranes themselves will hold water. So you got to have the seams either glued or heat-welded properly.

I see cracks in most of the places especially in the roofs, and I considered it to be the principal current problem with roofs. Horizontal, diagonal or vertical cracks may appear across multiple roofs. This is because roofs made by some manufacturers do not meet the standards for tear resistance. Likely other causes may include exposure to heat, sunlight and large temperature changes. 

The flow of water start frm Himalaya and end in the sea. A great achievment of gravitational force which is a act of nature. In this process some water is absorvede by the soil but it does not create marshes OR SOGGY SOIL..

Similarly if we take proper care and provide proper and accurate sloping roofs with adequate down pipes of proper sizes , the roof would never leak. Othe treatments like water proofing, coal tar application are of secondary uses and should be applied after the roofs have weathered for a considerable periods.This is alao true for flat roofs. the proper slope towards the outlet pipe and removing all posibilties of water stagnation is the only but  the only solution to avoid leaking floors and roofs

The down comer pipe need to be embedded properly . It has been observed that the floor traps laid under floors and the pipes connected are not properly  joined and is a constant source of leakage and nuisance value.Plumbing is a serious matter and should not be neglected in the absense of appropriate supervision.

Leakage is a menace for a building specially the roof. It really helps in spoiling the complete interior. In order to combat this problem one needs to be very careful in installing whatever systme is being installed.

All the systems be it APP/SBS membrane, Liquid applied flexible polymer coatings, Cementitious coatings, all has been designed to stop the leakage subject to proper application done by the expert. Normally back in India waterproofing is taken for granted though we have a tropical climate.

Client doesn't want to pay for it though it may cost 1% of the total project. If this mindset is changed then automatically all the leakages will stop. Because the installers will be paid nicely hence they would do the decent work.

On the basis of my experince in India heading a waterproofing application company.