Bituminuous waterproofing membrane have torch on membrane and self adhesive membrane. Torch on membrane is the more preferred one use because of its shelf life and ease of use during application.
The self adhesive type must be use fast as the bonding properties of the membrane is reducing through time. Very often applicators find the self adhesion membrane already lose its bonding properties when they want to apply. therefore, they have to use one additional primer to prevent the debonding problem in the near future.
Torch on membrane have exposed and covered types. Exposed membrane often has mineral granular aggregate to withstand the wear and tear of the weathering and the other types of membrane, contractor need to apply one protective screed to provent the puncture of the membrane.
But one has to be very careful when applying the protective screed which is often cement mortar. The cement ratio has to be high and the mixing has to be thorough through out the process. There are premixed type of cement mortar in the market available for use for better quality and consistency. Site mix usually will compensate the quality of the finish work but the cost is always cheaper compared to premixed mortar.