Third, the method of construction of cement cast channel attic because few people using, so we highlight the channel's take the law. If you're using a cement floor, then I suggest you refer to the relevant construction books. The following method is based on the construction of your room flat square to consider. 1, the channel floor of the most crucial point is fixed at both ends of the channel. There are three main fixation methods: one is on the wall with one another angle do is to make a hole in the wall, and then inserted into the wall channel by channel directly bear the weight of the wall. This method is limited to only load-bearing walls or thick shear wall. Another method is a direct vertical channel to another channel support horizontal, vertical in the channel to be fixed to the wall. This method is to consider the channel vertical location of the load-bearing capacity of the floor, and should support a distributed multi-point, not to force concentrated in a few of the channel up to bear, the third approach requires a channel, rather than the first One approach, as with the angle on the line. Generally fixed at the longest sides of the above, if the longest sides parallel laying no fixed condition, but also with the shortest sides were laying. 2, to solve the channel of a fixed point, the following must be addressed is the main keel arrangement. For the bedroom, it is generally recommended to use 120 × 60 × 6mm or more specifications of the main channel role keel. Main keel should be carried out in parallel with the shortest side laying interval of about 500mm. Channel must stand on top of the wall, and the wall of the gap of no more than 10mm. Channel fully welded on top rungs. If laid parallel with the shortest side no fixed condition, but also with the longest side parallel laying.