There is a subtle difference between damp proofing and water proofing. Damp proofing is tar based, whereas, waterproofing is polymer and rubber based. They have their own pros and cons, and the situations in which they are used are also quite different. It must be noted that the customs and techniques vary from region to region and thus, if you look at the broader picture, there are countless techniques of protecting the foundation of a building from moisture.
It is a technique where tar and mastic asphalt-based substances are used to treat walls, especially those connected to the basement from inside or outside. This type of proofing performs a capitally action, that is, it keeps the wall or structure from becoming excessively moist. The porosity of the wall or structure is filled with solutions which are just like paint. These asphalt or tar-based emulsions are applied on the outer surface of the wall, both inside and outside the building. They fill up the porosity of the wall by covering up and partially entering the minute holes. There are some solutions that are also sprayed on the wall, or are added to the mortar while the building is still under construction.
This proofing however, is highly susceptible to weather and it also grows weak after the construction starts wearing down. The problem is, with age, the porous parts of the wall and the small cracks expand and change shape, the emulsion is however not able to take up this new space, and moisture gets a free pass into the structure. In basements, or in places where the risk of damp rising is high, a special solution spray is applied on both sides of the wall, in cases where it is multi layered. The damp coating has to be updated once in a while, as it is not that foolproof and it tends to break down slowly in the first few years. It is used in regions where it rains moderately and the winter or summer is not very harsh either. This is because, it does not stop the high water flow but merely prevents the damp from accumulating on the wall. From a monetary point of view, the damp proofing process is cheaper than water proofing. Some common products include, Thoro T5200, and Karnak #920AF fibered exterior solution.
Just as the name suggests, this process prevents a flow of water from hampering the health of your wall or house. It is a bit different from damp proofing and from the point of view of construction, it is the best way to protect walls and foundations of the house. Waterproofing emulsions are basically rubber and polymer based which have two important characteristics, namely, elasticity and flexibility. Hence, the porous holes remain covered for a very long time, and with time, the membrane that gets formed tends to shift a bit as per the expansion of small holes and cracks. Emulsion, in most cases, is mixed with mortar as a concrete solution. In cases where the climate is extreme, it is additionally sprayed on the external portions of the wall. At the same time, a damp proofing basement solution is also sprayed from the inside section of the wall to curtail moisture growth.
Some basement proofing products that can be put to use in such a case include, Damtite Waterproofing Solutions and Seal Guard Waterproofing Membranes. The total cost is quite high but the durability of your home is assured, and you will never have the problem of any leakage. There are some additional costly emulsions that can be used for waterproofing wood structures in the basement.
Waterproofing the basement and the external walls of a building is thus the best choice in case you live in a very cold or rainy region. In conditions where the climate is relatively warm, damp proofing the building becomes a good option.