Hey everyone! I'm looking for some advice about installing a ceiling cassette for HVAC. The contractor says I'll need to cut 1-2 ceiling joists that are 16" on center to make it fit. He mentioned sistering the adjacent joists but told me a permit might not be necessary since it's not a huge structural change. Is this true? Would cutting those joists pose any safety concerns for my single-story house? Also, here's a picture for reference: [https://imgur.com/a/ggKypz7](https://imgur.com/a/ggKypz7)
3 Answers
Just a heads up, always use hangers and rated screws. It can work as long as you aren’t dealing with trusses. Human error can lead to messy modifications, though, so watch that.
Permits are not optional; they’re just either required or not, depending on your local laws. If these are joists and not trusses above your ceiling, it’s likely manageable load-wise, but checking local regulations for permits is a must before doing anything.
It's best to sister the joists for the full length of the span. I can't see all the details from the picture, but if the joists are just being cut without proper support, that could be a risk. Make sure to check that everything is structurally sound!
I thought the same! We looked in the attic, but the joists run under a wooden floor, so he can't sister them fully across. Seems a bit sketchy to me.
He said he's going with nails and construction adhesive. I hope that’s up to standard!