2

My condo is in an 8-story concrete and steel building, built mid-80’s in Massachusetts. My ceiling is 1/2” drywall screwed into 2-3/4” x 7/8” steel studs (Joists? Furring strips?). Those are hung with wire from the steel beams that support the cement floor above. The beams are 4 feet apart and the “studs” are 2 feet apart. (Photos of this at end of post.)

I’ve had no issue hanging light-weight swag lights using toggle bolts into the drywall. But I’d like to hang several heavier items at various points across the ceiling in front of my balcony door/windows. Static loads only: plants, plant shelves with 4-6 6-10" pots, grow lights, etc. I’m guessing some of these would be about 25 lbs eachI also want flexibility to move things around and reposition them as needed.

Here’s the area I’m referring to: Ceiling above balcony windows and door

Photos inside my ceiling (over some closets where I have access).

I'd love to add supports above the ceiling, but at this point I do not want to cut into the drywall. The only access into the ceiling where I need to hang things is possibly where the 4" recessed lights (not shown in photo) and HVAC registers are. I haven't actually tried it. I also don't own the beams and concrete above the studs, so technically shouldn't use them.

I could just put a bunch of toggle-bolts all over the ceiling into the drywall and/or studs, but I assume that wouldn’t be strong enough for heavier things.

I've gotten some opinions/advice from various folks, but I’d love some additional expert advice. The consensus approach seems to be to surface-mount wooden supports, perpendicular to and spanning 2 studs, then attach hooks etc. into that. Questions:

  1. Does this sound strong enough?
    1. If so, how much weight do you think each board could support?
    2. If not, what would you suggest?
  2. Could I use 1x6 boards instead of 2x4s? 1x3s or 1x4s?
  3. Would I need a hardwood like oak or maple, or could use pine or poplar?
    1. What about PVC or vinyl boards?
  4. Could I use something like slotted angles or slotted square tubing instead of wood?
  5. Would self-tapping sheet metal screws be the way to connect to the studs, or would drilling and using toggle-bolts bet better?
  6. Should I also attach to the drywall itself with toggle-bolts?
    1. Would snap-toggles be best?
  7. I could extend the boards to the narrow bit of wall between the balcony windows and the ceiling and add shelf brackets or angle braces from the board to the wall. Would this add any useful support?

I also have a crazy alternative that would be a much bigger project: Building a minimal support structure around the window area from floor to ceiling. No idea what low-profile material I could use, but the basic idea:

  1. A leg on each side, from floor to ceiling, secured to the wall, with a cross piece connecting them along the ceiling. I guess this would also be screwed into the drywall and studs?
  2. Angle braces above the windows adding support and stability to the cross piece.
  3. Supports from the cross piece extending out a few feet, also secured to the studs through the drywall. I would hang the plants etc. on these.

Thanks for any advice, warnings, or additional ideas!

Here is how my ceiling is constructed, over some closets where I have access (additional ceiling photos):

Ceiling construction

5
  • To either side of the door there should be some sort of "stud pack" with substantial strength against gravity loads with quite a bit of eccentricity from the wall. Are you open to a couple of brackets at these "stud packs" with some sort of beam across for carrying your pots? If ugly is okay, you could use standard parts for a closet hanger rod.
    – popham
    Jan 5 at 1:34
  • 1
    Do NOT drill into the web or flange of any I-beams in your ceiling. Use clamps to attach things to the flange. Also, this is far too broad. I see at least a dozen questions, and this site doesn't work well that way. Please take the tour, then look through how to ask a good question, then edit this down to one good, specific question.
    – FreeMan
    Jan 5 at 12:15
  • @popham -- in a curtainwall building, there may not be a typical "stud pack" to hold up even a long header, because the curtainwall isn't bearing loads to begin with Jan 5 at 12:39
  • You need to check with your condo board/association/whatever. They may limit penetrations of the structural ceiling.
    – Huesmann
    Jan 5 at 13:48
  • @ThreePhaseEel, I was referring to the "pack" of king studs, not jack studs. Curtain walls still must resist wind. When you displace a chunk of wall with a glass door, all of the displaced lateral resistance gets moved to the perimeter of the missing chunk of wall. Floor to ceiling tends to be the shorter distance to span (instead of horizontal "girts") in a residential structure, so there should be a concentration of wind-resisting elements oriented vertically along both sides of the glass door.
    – popham
    Jan 5 at 15:50

2 Answers 2

5

What you have there is a steel web truss with hat channel attached to the bottom. The hat channel gives you an attachment point for the drywall as it cannot span the 4' spacing that you have between the trusses.

To support something heavy without modifying or drilling into the steel you could use a beam clamp that is designed to accept a piece of all thread. You can hang a shelf from these pieces of all there or even get a hook attachment that hang a single plant.

Image source: Home Depot. beam clamp with all thread

1
  • 1
    The big question would be how to get a beam clamp attached to the beam without cutting a huge hole in the ceiling. Jan 5 at 18:54
2

I think you're right to avoid using ceiling drywall alone to support any but the lightest of things. The furring strips between the drywall and the trusses will hold a fair amount, say 10 pounds at least, but you're looking to suspend much more.

Those steel trusses surely could carry 200 pounds at a point. They appear to use a pair of L-angle as their bottom flange and have a sizeable gap between them. If you could devise a clever attachment your board-below-drywall could be suspended from the trusses rather than anchored to the walls.

Get a bolt, say 1/2" diameter by 6" long. Also a large, heavy washer - the big square ones used with Unistrut/Super Strut might be a good choice. Drill a hole through the drywall so that it is aligned with the gap. Drop the bolt through, then use a washer and nut on the room side of the ceiling to support a board. Use a second nut jammed against the first to prevent it working loose.

How do you get a bolt dropped through the gap and ceiling hole when it's many feet out of reach? Trickery. :-) Raise a loop of string through the hole in the ceiling and pull it back to you with the help of wire fishing rods. Tie the string to the threaded end of the bolt. Pull the string back into the room, dragging the bolt across the ceiling toward its new home. The bolt will need some help to get up and over the flange of the truss - I haven't quite solved that challenge yet. Maybe a length of vinyl tube as a leader at the nose of the bolt could help.

enter image description here

Also.. if you just really need a small access hole or two, cut in a low voltage wall bracket and then cover with a blank electrical plate. No drywall repair needed.

3
  • J-bolts? Mn = min{(36000psi)(1/6)(1/4")^3, 1.6(36000psi)(1/32)(3.14)(1/4")^3} = 88.3#-in (F11-1 from AISC Spec. Tension strength, then, is (1/1.67)(88.3#-in) / [(1/2)(1/4"+5/8")] = 121#.
    – popham
    Jan 5 at 6:52
  • @popham Nice, yeah L or possibly J bolts could be inserted blind from below rather than having to feed them across the ceiling!
    – Greg Hill
    Jan 5 at 20:13
  • Ah, you like the L shape because you can sneak them through such a small drywall holes? Is that it? I would be afraid of them rotating to disengage. Maybe you could bend the L shape a little to get an acute angle that would better thwart any disengagement by rotation. There's no fireproofing on that steel and I don't see sprinklers in the OP's question, so I suspect that the drywall is that steel's fire protection. I strongly agree, then, with any trick to reduce the size of punctures.
    – popham
    Jan 5 at 22:30

Not the answer you're looking for? Browse other questions tagged or ask your own question.