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cathedral ceiling box beam help

dap's picture

Hello all! Newbie here.  Great site, lots of good info.  Posted this in the Knots forum, hope there might be some different ideas here.


Looking for some info on building box beam.  want to hang beam from 15' cathedral ceiling. House in frame stage now.  Any info on making the box beam itself?  Should the box have square corners, or recessed into dado, with some sort of trim?  Plan to hang from 2x6, 2x8 nailed to rafters.  Anyone have a source of pictures for this sort of thing?  


Any help would be appreciated.


Thanks. 

There is a fine line between "Fault" & Character!

(post #64052, reply #1 of 17)

dap.. it's all a question of scale..


 is there a ridge board ?   how long is the ceiling  i know it's 15' up.. but how big is the area ?


i'd frame it  and trim it after the sheetrock is up...


Mike Smith Rhode Island : Design / Build / Repair / Restore

Mike Smith Rhode Island : Design / Build / Repair / Restore

              www.mfsmithbuilder.com

(post #64052, reply #3 of 17)

Mike,


Sorry, but explain "ridge board"? I am thinking as in rafter tie?  If so, then yes there is ridge board.


As to the area, the room is aprox 20'x24'.  Each side of the beam would be aprox 20'x12'.


The plan is to install horizontal 2x to joists at peak, and gypboard up to this 2x.  would then attach beam to the 2x.  Only part showing would be the "new box beam".  Does this make sense? 


Would like this box beam to be dressed with 1x oak on 3 sides. Not sure weather to square corners or recess 3/4" and add cove molding?


Suggestions?


Thanks.

There is a fine line between "Fault" & Character!

(post #64052, reply #2 of 17)

are you saying you just want to dress up the rafter ties?

(post #64052, reply #4 of 17)

Maverick,


No, the rafter ties, and all rafters will be hidden under drywall.  This beam will hang from the ceiling (on 2x mounted to drywall) and only be decorative. Will build the beam from 3,  1x?s oak, and hang from the 2x? mounted to the ceiling.


Thanks.

There is a fine line between "Fault" & Character!

(post #64052, reply #5 of 17)

If that's the case, finish your gyprock and paint it, then screw 2x2's onto the ceiling surface so your box sides just fit over them. You can then screw into them sideways at the joint with the ceiling.


As for the construction of the beam itself, simple air-nailed butt joints with the bottom piece spanning the full width of the box would be the easiest and most likely won't be seen from 15' below if you finish it nicely. I know that puts the nails holding the bottom piece in tension--but a 1x isn't heavy and air nails have glue on them. Nail on 12" centers and it won't fall apart.


Dinosaur


'Y-a-tu de la justice dans ce maudit monde?


 

Dinosaur

How now, Mighty Sauron, that thou art not brought
low by this? For thine evil pales before that which
foolish men call Justice....

(post #64052, reply #6 of 17)

Thanks Dinosaur,


What you say makes sense to me.  I was unsure of drywall first, or cleats first.  Any opinion on which would be easier to slip a 10' beam on and keep straight and centered.? (this is a old one man crew)  Looks like the beam will have to be spliced in the center to accommodate a ceiling fan, but would have to be spliced anyway.  Your right, nailing center board between 2 sides would be the easiest, but I am hoping for something a little more artistic, but still buildable 15' in the air.


Wacha ya think?


dap


 

There is a fine line between "Fault" & Character!

(post #64052, reply #10 of 17)

You might also want to consider using these.

http://www.pcfoam.com/interior1a.htm

Knowledge is power, but only if applied in a timely fashion.
Knowledge is power, but only if applied in a timely fashion.

(post #64052, reply #14 of 17)

Had considered this, but they usually look like @#%$.  Although this site has much better looking !@#%$ than usual.


 


Thanks.

There is a fine line between "Fault" & Character!

(post #64052, reply #12 of 17)

For the ceiling fan: just run your fake beam full length and mount the fan on in and run your wires inside it. Hook the safety wire to solid wood on a rafter, tho. Make up a longer safety wire if necessary.


Can't quite follow your question about which (which what?) would be easiest to slip on (where?). The way I'd build this would be to snap chalklines on the gyprock to lay my 2x2 cleats on and then screw them in place through the gyprock to the rafters or collar beams. Then air-nail or screw on the side pieces of your boxbeam to the cleats. Then finally nail on the bottom. I would not put the bottom piece between the two sides as the joints will be visible from the floor. I would nail it up under them, covering the bottom edges of each side piece. This will leave your visible butt joints on the sides of the beam, where they will be much harder to see from the ground. But do remember that only the guy that built it will spend any more than a second or two craning his neck to stare at it, LOL....


I would use a rolling set of scaffolding if I were working alone and limit the length of the individual pieces to no more than 10 feet. Still better to try to get a helper up there on the scaffolding with you for the short time it will take.


If you pre-finish all the pieces, you won't have to go back up to stain/paint anything except filling the nail holes.


 


Dinosaur


'Y-a-tu de la justice dans ce maudit monde?


 

Dinosaur

How now, Mighty Sauron, that thou art not brought
low by this? For thine evil pales before that which
foolish men call Justice....

(post #64052, reply #15 of 17)

Thanks Dinosaur,


This is just what I wanted to hear.  How would you do it.  Liked the idea of putting the bottom piece on the sides, not between.  Your right, joint's wont show from floor.  To bad all this work won't receive more than a passing glance, but that is the way of trim.  Unless it is bad, and then everyone comments on it.


Rolling scaffolding with helper sounds like good idea also.


 


Thanks again.

There is a fine line between "Fault" & Character!

(post #64052, reply #16 of 17)

I rip the 2X cleat to whatever the inside dimension is, that way only having to position one piece, then nail my mitered side pieces, then glue & brad nail my mitered bottom on.


greg

(post #64052, reply #17 of 17)

Thanks gb wood,


Nice job. Appreciate the photo.  Like the look of the beam as it comes down both sides of the wall/ceiling. Finishes the beam.


 


Thanks again.


Dap

There is a fine line between "Fault" & Character!

(post #64052, reply #7 of 17)

why not use a real beam?  no matter what you do to a box beam it always looks like a tacky gimmick to imitate a real beam. you may find a real beam is cheaper than any cheap fake too! 


  For example I can get white oak for 80 cents a bd.ft.  that means if I were to buy a 6x12 inch beam 20 feet long it would cost  96 dollars.  or a 6x6 would cost $48.00 ash is slightly less while black walnut would be about twice as expensive..


  the great thing is that a real beam adds to the strength while a tacky immitation sutracts from strength.. one further point,  a real beam will take less labor to plane and install than a fake.

(post #64052, reply #8 of 17)

Frenchy,


I couldn't agree more, Real beam would look like a beam.  Not a box.  How would you hang a beam this size though?  Shouldn't it be used as a ridge beam, and rafters hung from it?  Wouldn't the weight of a true beam cause structural problems.  Then again just one beam with no supports at either end might look a little odd. 


Thanks.


Dap

There is a fine line between "Fault" & Character!

(post #64052, reply #9 of 17)

dozens of ways but I'd go a step further and turn the beam into a faux timberframe. land the "rafters"  in a pocket built by tradional stick building and you won't need to go to the effort to make a real timberframe..


 at the peak you can lag bolt on the top side and other than cutting to the correct angle that's the extent of "timberframing"  skills you'll need.  

(post #64052, reply #13 of 17)

Thanks for the idea.  Will kick this one arround and see where it goes.


dap

There is a fine line between "Fault" & Character!

(post #64052, reply #11 of 17)

Looking for some info on building box beam. 


For a purely decorative beam, the only framing you really need is soem sort of 2x to fasten it too (and whatever "dead" wood the ceiling treatments will want adjacent to the beam).


For the visible "beam," I like to rabbet the bottom "inside" edges half their depth, both ways.  Then, the "bottom" of the beam sits in those rabbets, giving a nice clean joint between the three sides.


I like to stagger all three joints along the length of the beam.  I prefer to half-lap the joints, back-beveling the "top" joint to get a good tight fit (a little dark stain, or black permanent marker in the other joints often does not go amiss, either).


Occupational hazard of my occupation not being around (sorry Bubba)
I may not be able to help you Occupational hazard of my occupation not being around (sorry Bubba)