砖混住宅楼大多设有通风道及屋面排汽管。屋面排汽管是为了排出保温层内水分,防止防水层起鼓、开裂而设的。通风道一般设在楼房进深的中部,这样可将排汽管及通风道出屋面部分合二为一。具体作法如下。将屋面找平层的分格缝有目的地向通风道出屋面部分集中(图1),找平层分格缝以纵横间距6m 为宜,缝宽25～35 mm,兼作屋面 Most of the brick-concrete residential buildings have ventilation ducts and roof exhaust pipes. The roof exhaust pipe is designed to discharge the moisture in the insulation layer and prevent the waterproof layer from bulging and cracking. Ventilation passages are generally located in the middle of the building’s deep, so that the exhaust pipe and the ventilation passage out of the roof can be combined into one. The specific practices are as follows. The compartmental seams of the roofing screed are concentrated to the roof of the ventilation ducts (see Figure 1). The screeding compartments are suitable for vertical and horizontal spacing of 6m, and the seam width is 25-35 mm, which doubles as roofing.