Dear Tracy,
The use the proper cable rating (CMR, riser rated or CMP, plenum rated) in a residence will be dictated by your local codes. In most cases if the cable will be run in a plenum space, then a CMP rating will be required. An example of this would be if the home has a central air conditioning system and the attic space is used for the air return then the attic space would be considered a plenum. If any portion of the cable is run through this space (without other protection i.e. conduit) then the cable should be plenum rated. Another consideration would be even if the home could have an air conditioning system added later then I would run plenum rated cable now.
You can always use CMP cable in place of CMR. For the small cost difference for a residential cabling system, I personally would always use plenum rated.
You should always check with your local inspector or AHJ (Authority Having Jurisdiction) for the final word.
Sincerely,
Joseph Golan, RCDD
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