The flat roof will show a wavy shape, a sinking middle, or an uneven flat top. There are many reasons for this phenomenon, mainly the following: (1) The horizontal baseline was accurately ejected four weeks before the ceiling was lifted, or it did not follow the horizontal baseline. (6) Deformation of wooden keel, bending of light steel keel is not adjusted. When fixing the water boom, the boom must not be cracked, nor can it be fixed with a fine wire needle to prevent the wood boom from coming off. Hangers avoid the use of wire, especially the pedestal flat top, because the flat top itself is relatively heavy, due to poor anti-fatigue strength of the wire, after the force will extend, causing the flat top sink. Keel deformation should be avoided when installing the keel. When the water keel is used, the moisture content of the keel should not be more than 15% in Shanghai and not more than 12% in the dry area to avoid deformation of the keel. When installing the keel, special attention should be paid to the distance between the keel suspension wall should not exceed 300mm. Additional booms should be added at the two main keel joints. When the suspenders and keel are adjusted, arches should be made in the middle part, and the arches are generally 1/2 OO in the short span of the room. When the concealed flat top is fixed on the cover panel, the screw tails should not be exposed. After the joints are batch-applied and seamed, a full batch shall be made so that the joint between the cover panel and the middle part is a plane. After flat roof construction, dampness should be avoided, especially light flat roof. Air-conditioned room Aluminum 300*450mm LED Panel Light Foshan Nanhai Lianxing Deli Decoration Materials Co.,Ltd , https://www.fstuodeli.com
(2) The end of the suspender in the middle of the flat top is adjusted upwards, not only not arching but instead sinks due to the middle load of the intermediate boom receiving the flat top.
(3) The distance between the booms is too large or the keel cantilever distance is too large. The deflection caused by the keel force causes flat tops and undulations.
(4) The wooden boom spalling did not work.
(5) The boom was not carefully adjusted and the local boom was not evenly stressed.
(7) Thickness of the joints of the panel of the concealed flat top cover caused the joints to protrude, resulting in the formation of flat tops and undulations.
(8) The cover panel deforms after absorbing moisture.
Therefore, before the flat top is hoisted, the materials used must be selected, checked, and the materials that do not meet the requirements must be removed. In the construction, according to the height determined by the flat top, a horizontal line is popped up on the surrounding walls. According to the materials used in the room and the top of the room, the materials and arrangement spacing of the hangers are determined. Generally, the horizontal spacing of the hangers is 900-1200mm. Hangers should be used for special suspenders, steel bars, etc. When wood materials are used, wood that is not rot, crack, or hard is selected.
The flat roof is required to be firmly installed, not loosened, and the surface is flat. Therefore, before the flat top cover is lifted, the installation of the hanging point, the boom, and the keel must be inspected. Loosening of the hanging point, bending of the suspender, deflection of the suspender, and keel must be checked. In case of looseness, unevenness, etc., the construction personnel shall be supervised to make adjustments. If electric cables, water supply and drainage, and air-conditioning pipelines are laid in the flat top, the panel must be sealed after the installation is completed and debugging is in compliance with the requirements, so as to avoid damaging the flat top and affecting the formation of the flat top. After the cover panel is installed, it should be inspected whether it is flat or not. Generally, it is checked by observation and manual test. If necessary, the flatness of the cover panel can be checked by pulling the wire and measuring the amount.