Windows are required to be flexibly connected to the structure, allowing a small amount of deformation under external load!But waterproofing mainly depends on sealant!The picture set was originally filled with slag cotton more, and now as plastic steel window use foaming agent.Plastic steel doors and Windows have the characteristics of heat expansion and cold shrinkage, so the seal between plastic steel doors and Windows and wall interface is a moving state of seal.Generally, the expansion and contraction value of plastic steel doors and Windows can reach more than 10mm. In order to ensure that plastic steel doors and Windows can expand and contract freely after installation, the inner cavity of Windows and walls should be filled with elastic materials.If the cement mortar that USES dry and hard only is sealed, cannot satisfy this one requirement, because the heat conduction coefficient of mortar is high again, the meeting of day is contractive and dry crack, affect the airtight of door window more, watertight and soundproof sex.In addition, the advantages of elastic materials such as shock resistance, crack prevention, waterproof, fire prevention, heat preservation and strong adhesion are incomparable with the dry hard cement mortar.The elastic materials used at present include anticold felt strips, foam plastics, silicone foam sealants, polyurethane foaming agents, which are widely used.There are two waterproof measures on the side of aluminum alloy doors and Windows:In the first line of waterproof measures are: aluminum alloy doors and Windows and walls around the joint, the first outside surface frame and wall body crack location using wood as temporary joint sealing, filling foaming agent by indoor to outdoor window frame slot injection, until the tank full, dense, outside the basic level, after waiting for foaming agent basic dry solid wood.Then apply 2 mm water repellent to the outside foaming agent surface to complete the first waterproof work.The second waterproof measure is: civil construction personnel cooperate to paint the outside of the hole, and reserve 5 ~ 8 mm deep groove around the window frame.After the paint is basically dry and fixed, fill the groove with waterproof glue.Therefore, blowing agent is a very important waterproof measure.The thermal expansion coefficient of aluminium alloy is about 23 mu - k m/m (20-100 ℃)Whether it's an aluminum window or a plastic window, the principle is essentially the same.That is, the thermal expansion coefficient of aluminum alloy profiles and wall materials is different. Under the influence of temperature, the connection between frame and wall is easy to produce hairline cracks.In order to prevent water from seeping through cracks, elastic connections should be made between aluminum alloy door window frames and walls.