//www.tianyujian.com/談到將卷材防水層粘貼在地下工程結構的迎水面通常稱外防水，貼于背水面稱內防水。卷材外防水可以保護地下工程主體結構免受地下水有害作用的影響；防水層可以借助土壓力壓緊，并可和承重結構一起抵抗有壓地下水的滲透。
Jinan professional waterproofing waterproofing membrane comes to be attached to the positive side of underground engineering structures usually called outer waterproof, affixed to the back surface of the water, said water-resistant.
Waterproof outer membrane of the main structure can be protected from the effects of underground harmful effects of groundwater; waterproof layer can make use of compacted earth pressure, and the load-bearing structure together and resist pressurized groundwater infiltration.
//www.tianyujian.com/介紹內防水做法不能保護主體結構，且必須另設一套內襯結構壓緊防水層，以抵抗有壓地下水的滲透，有時甚至需設置錨栓將防水層及支承結構連成整體。因此，一般掘開施工的地下工程都不采用內防水做法，只是暗挖施工的地下工程，必須采用卷材防水而又無法采用外防水做法時，才采用內防水做法。
Jinan professional waterproof waterproof introduce the practice has failed to protect the main structure, and must be a separate structure lined with waterproof layer pressed to resist pressurized groundwater infiltration, and sometimes
need to set anchor waterproof layer and the support structure integrally connected. Therefore, the general construction of dug underground engineering practices are not using waterproof, but the construction of underground tunneling project, waterproof membrane must be used with external waterproof but can not practice, practice before using waterproof.