how should I cut open sheetrock ceiling to run romex for recessed lighting
#1
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Thread Starter
how should I cut open sheetrock ceiling to run romex for recessed lighting
I have a flat roof and no attic. the drywall is on 2x10 horizontal rafters on 16in centers
I have electric at an old cieling fan box that i need to run out both perpendicular and horizontal to the rafters to get to the holes for the lighting cans.
1. should I cut and remove sections 4" wide and 16" long so that I can run wires and drill holes thru the joists and then screw back those 4" wide strips of drywall and tape seams and mud the joints
or
2. shold I cut little 4x3" pieces of drywall at each joist so that I can notch that joist for the romex and then try to snake the romex from one hole to the next. now i will have to screw back theses 4x3 pieces and mud them in place
3. should I try a flexbit which might ruin all the insulation in the cieling and maybe drill holes too close to the edge of teh rafters
how do pro's do this ?
I have electric at an old cieling fan box that i need to run out both perpendicular and horizontal to the rafters to get to the holes for the lighting cans.
1. should I cut and remove sections 4" wide and 16" long so that I can run wires and drill holes thru the joists and then screw back those 4" wide strips of drywall and tape seams and mud the joints
or
2. shold I cut little 4x3" pieces of drywall at each joist so that I can notch that joist for the romex and then try to snake the romex from one hole to the next. now i will have to screw back theses 4x3 pieces and mud them in place
3. should I try a flexbit which might ruin all the insulation in the cieling and maybe drill holes too close to the edge of teh rafters
how do pro's do this ?
#4
Member
Thread Starter
I dont think the ceiling is strapped. just 2x10 rafters with insulation and drywall .
why is notching bad? I would put a steel cover plate over it
if i try to drill a 3/4" hole thru teh joists to pass the romex, doesnt that also weaken the joist?
also it is hard to guide the flex drill bit to cut the the hole a few inches away from the edge (where the drywall is attached. ?
I guess my main question is if i cut away long strips of drywall to insert the romex and then replace those drywall strips, will i see two long scars on the ceiling where I patched the strips?
why is notching bad? I would put a steel cover plate over it
if i try to drill a 3/4" hole thru teh joists to pass the romex, doesnt that also weaken the joist?
also it is hard to guide the flex drill bit to cut the the hole a few inches away from the edge (where the drywall is attached. ?
I guess my main question is if i cut away long strips of drywall to insert the romex and then replace those drywall strips, will i see two long scars on the ceiling where I patched the strips?
#5
Member
Thread Starter
what electrician? this is a DIY forum :)
why is notching the joists bad? I would put a steel cover plate over it
if i try to drill a 3/4" hole thru teh joists to pass the romex, doesnt that also weaken the joist?
also it is hard to guide the flex drill bit to cut the the hole a few inches away from the edge (where the drywall is attached. ?
I guess my main question is if i cut away long strips of drywall to insert the romex and then replace those drywall strips, will i see two long scars on the ceiling where I patched the strips?
#6
We have members/mods that are electricians, I'm a painter.
Drilling a hole in the middle of a joist doesn't weaken it much if any but cutting a notch out of the bottom creates a weak point.
How well a drywall patch blends in depends on how well it was finished/textured. Normally the repair will extend a good ways out from the actual patch.
Drilling a hole in the middle of a joist doesn't weaken it much if any but cutting a notch out of the bottom creates a weak point.
How well a drywall patch blends in depends on how well it was finished/textured. Normally the repair will extend a good ways out from the actual patch.
#7
It's one thing installing recessed lights in an un-insulated ceiling. Insulated is harder. I personally would opt for a 1/2" max notch in the rafter, nail plate and respackle. Plan your wiring so there is only one notch per rafter.
I found this piece when checking around. Also.... no holes or notches shall be located in the middle one-third of the span.
DocumentCenter/View/61
I found this piece when checking around. Also.... no holes or notches shall be located in the middle one-third of the span.
DocumentCenter/View/61
Last edited by PJmax; 09-26-17 at 12:19 PM.
#8
Member
Thread Starter
We have members/mods that are electricians, I'm a painter.
Drilling a hole in the middle of a joist doesn't weaken it much if any but cutting a notch out of the bottom creates a weak point.
How well a drywall patch blends in depends on how well it was finished/textured. Normally the repair will extend a good ways out from the actual patch.
Drilling a hole in the middle of a joist doesn't weaken it much if any but cutting a notch out of the bottom creates a weak point.
How well a drywall patch blends in depends on how well it was finished/textured. Normally the repair will extend a good ways out from the actual patch.

yes, i see your point that notching a stud weakens more than drilling a hole. if anyone is interested here is a link that describes the max number of notches and/or holes you can make (as per code).
https://www.familyhandyman.com/walls...tuds/view-all/
i guess I really need drywall advice regarding how best NOT to show the seams after I patch.
#9
Member
Thread Starter
thx.
has anyone here actually used a flex bit to span a few joists behind drywall and blindly drill holes thru the joists.
1. im afraid it will bugger my insulation
2. im afaid it will drill holes close to the edge of the studs(rafters)
i want to make as few scars in the ceiling as possible
has anyone here actually used a flex bit to span a few joists behind drywall and blindly drill holes thru the joists.
1. im afraid it will bugger my insulation
2. im afaid it will drill holes close to the edge of the studs(rafters)
i want to make as few scars in the ceiling as possible
#11
The flex bit will bind up going through the insulation and create large cold spots.
Notches weaken the wood because the depth is reduced. Holes in the middle of a joist do not weaken the wood.
I would do the strip or look at possibly running in the soffit outside the wall.
Notches weaken the wood because the depth is reduced. Holes in the middle of a joist do not weaken the wood.
I would do the strip or look at possibly running in the soffit outside the wall.
#14
Are there any closets or cabinets on opposite walls you could fish in and out of , also one way to patch would be to use a utility knife and score lines in the drywall the width of the drywall tape and just deep enough for the tape to lay in flush,try not to remove all of the paper,apply some mud and sink the tape into the cut, and smooth it out,let it dry and recoat as needed,as mentioned the mud must be feathered out away from the actual patch and sanded smooth.
Geo
Geo
#15
In your situation I normally cut a channel of drywall out, drill holes through the joists to run my cables, then reattach the same drywall. It is just as easy (or easier) to repair a long slot then a bunch of small holes. Plus the repair will look better. I normally cut a channel 4-6" wide and as long as needed to get access to all the joists spaces.
#16
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Location: Kansas City Area
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Think about Crown Moldings
Hopefully I'm not too late to this party for a response.
Have you considered crown molding? Instead of cutting thru a lot drywall & repairing it all, put up crown molding around the perimeter walls. You can use the cavity behind as a raceway by nailing up 2x2 or some other sized board against the wall behind the crown and if you size it right it also gives a place to nail the crown against. Fish up & thru the joist space when you are at the ends where the cans will be, then use the crown raceway while running perpendicular to the joists. Pop up & down as needed at the edges behind where the crown will hide. After all wiring is done & before nailing the crown in place, stuff insulation or spray foam into the holes. Not sure if anyone here has mentioned this, but be sure to install cans that will allow direct contact with insulation.
Painting the Crown will also allow you to use putty / filler to fix all nail holes and joints that don't fit tight. This adds an architectural aspect / improvement to the house and in my perspective is easier than all of the drywall fixes. Especially on ceilings as those show even small imperfections.
Think about it. Improve the look of the room two ways with both new lights & crown moldings.
Have you considered crown molding? Instead of cutting thru a lot drywall & repairing it all, put up crown molding around the perimeter walls. You can use the cavity behind as a raceway by nailing up 2x2 or some other sized board against the wall behind the crown and if you size it right it also gives a place to nail the crown against. Fish up & thru the joist space when you are at the ends where the cans will be, then use the crown raceway while running perpendicular to the joists. Pop up & down as needed at the edges behind where the crown will hide. After all wiring is done & before nailing the crown in place, stuff insulation or spray foam into the holes. Not sure if anyone here has mentioned this, but be sure to install cans that will allow direct contact with insulation.
Painting the Crown will also allow you to use putty / filler to fix all nail holes and joints that don't fit tight. This adds an architectural aspect / improvement to the house and in my perspective is easier than all of the drywall fixes. Especially on ceilings as those show even small imperfections.
Think about it. Improve the look of the room two ways with both new lights & crown moldings.