Guide how to Installing a Ceiling Fan

Installation between joists is OK, too. Fasten the box to a 2x4 header nailed between the joists. Sometimes, you can insert a 2x4 header through the junction box's hole, nailing it to each joist. If not, you may need to open a larger access hole. Then, patch the hole to close it again. You may choose to use a patented fan support unit designed to be inserted through the normal junction box hole to save you from opening a hole in the ceiling. Use only a metal junction box to support a ceiling fan–never hang the fan from a plastic box. Depending on the brand, style, and size of your ceiling fan–and your electrical code – you may use a 4" or 3" octagonal junction box.

(Some local codes don't permit the use of 3" boxes.) The heaviest fan that should be supported by an outlet box is 35 lbs.. If it weighs more, the building structure must support it. Whatever you do, make sure the junction box is supported well enough to hold at least 50 lbs. That's the weight of an average ceiling fan. Also, your mounting must be able to withstand vibration while the fan is running. Even a well-balanced fan creates some vibration when it runs. You'll use a special beam mount when mounting a fan to a beamed ceiling. Use one kind for a horizontal beam, another for a pitched beam (Fig. 3). You may need an extender to lower the fan to the proper level. Fan-mounting is particularly important because any failure to make things secure could allow your fan to fall from the ceiling.
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