Cathedral Ceiling

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Old 10-14-14, 06:51 AM
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Cathedral Ceiling

I took down the ceiling and the rafter ties in this small addition on the back of my house. I'd like to keep it open. The rafters are 2x6 with a 2x6 ridge board. The room is only 10x12. Height of the ceiling is 10' from floor to peak. My question is: would a couple of 2x8s with plywood in between suffice as a ridge beam placed under the existing ridge board? One end of the ridge is secured to the existing side wall of the main house. I figured that would help with the load as well. Appreciate any advice. Thank you.
 
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Old 10-14-14, 06:54 AM
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Welcome to the forums.

We need pictures right away, your post has me very concerned you have affected the structure of your house.

http://www.doityourself.com/forum/el...rt-images.html
 
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Old 10-14-14, 07:03 AM
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Can't figure out how to upload images from my iphone.
 
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Old 10-14-14, 10:42 AM
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here's one end of the gable.
 
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Old 10-14-14, 10:45 AM
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here's the other end where it ties into the side of the house.
 
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Old 10-14-14, 11:17 AM
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How about where the rafters are sitting on top of the walls?

Additionally, are there any 'before' pictures?
 
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Old 10-14-14, 11:19 AM
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Yes, I think that is what Mitch was concerned about. Those rafter ties (ceiling joists) shouldn't be removed without adding support somewhere.

What you want to do with a strong ridge beam is possible, however, what supports each end of that beam is critical, especially in MA. Regardless of what you think will hold that roof up, it must meet code and snow load requirements. The end shown that is attached to the house looks like it is over a header.

Basically, you need someone, code official or engineer, to sign off on what needs to be done. If you cobble it together, you become responsible forever.

Bud
 

Last edited by Bud9051; 10-14-14 at 11:20 AM. Reason: correction
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Old 10-14-14, 12:47 PM
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Thank you for the quick replies, gentlemen. I'll see if I can find some "before" pics. Basically it was a few 2x6s spanning the top plate with only some 1x material tying them into the rafters. Even if I decided to scrap the whole idea and replace it the way I found it, I don't think I would be comfortable with it structurally. This addition was put on in the early 80's, and I am quite positive that the framing is outdated. It has lasted 30 years with the snow loads and everything else. I just feel that adding a ridge beam can't hurt.

I am also concerned with the fact that one end of the rafter is sitting over a picture window with a rather flimsy header over the window.

The pictures that I posted make this room look much larger than it is.
 
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Old 10-14-14, 01:10 PM
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The concerns that have been expressed have to do with the roof loads pushing on the side walls. The rafter ties that you removed were responsible for keeping the side walls from being pushed outward by the weight of the roof. The roof forces go up exponentially when there is the addition of snow on the roof. They are concerned about a collapse.
 
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Old 10-14-14, 01:18 PM
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before pic

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I understand the whole triangle concept, but I thought that a ridge beam could pick up the load.
 
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Old 10-14-14, 01:23 PM
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I totally agree. Thank you.
 
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Old 10-14-14, 01:24 PM
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Ugh.

I think you should get a structural engineer to come out and take a look at what you have.
 
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Old 10-14-14, 01:32 PM
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That bad? Lol

Thank you for your time. I appreciate it.
 
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Old 10-14-14, 03:43 PM
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I see drywall on the walls, how do you intend to finish the rafters? Code level insulation plus venting would require much more depth than a 2x6. Are you intending to vent above the insulation?

As a side note, I just had to jack up a triple 2x10 beam that wasn't supported properly. Now I'm sure it looked fine when the house was built, but 35 years later it had sagged almost an inch. Point being, without the bottom chord for that triangle, those walls will at the minimum sag sideways. Same goes for that header that is rather minimal.

Take your pictures and plans into a lumber yard, not a box store, where they can do the load calculations to determine what size piece of engineered lumber you need for a header. It isn't very long and they know your snow loads and will comment on other improvements needed.

Bud
 
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Old 10-14-14, 04:04 PM
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Thanks, Bud. I had planned on firring out the 2x6s with some 2x4s (to get a better R value) and using strips of plywood to tie them together. I had also planned on putting baffles in as well. I just might have to go with collar ties instead of a ridge beam and put this mess back together. It's not turning out like I had planned.
 
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Old 10-14-14, 04:33 PM
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It is a lot easier to get code level insulation above a flat ceiling. Lots of threads on the difficulties of insulating and ventilating (or not) a cathedral ceiling. I did a remodel on a 12' x 24' front porch that had a 7' ceiling. We used scissor trusses to vault the ceiling and the results were impressive. Turned that room into a charming area.

It seems a shame to just back out at this point, although it would be a bigger project than first planned. One thought would be to move the ceiling up a foot, a vault of sorts. Given the small size that might be possible without extensive engineering. But however you decide to tie those walls back together you should pre-load them by pulling them in before fastening. Hard to say how much, but if the span is supposed to be 12' it shouldn't be any more.

I use a local lumber yard all the time as they design trusses so are quite capable of doing all load calculations.

Bud
 
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Old 10-14-14, 07:50 PM
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Thank you, Bud. I think I'll just stick to making cabinets : )
 
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Old 10-15-14, 01:33 PM
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I've decided to take your advice, Bud. I'm just going to move the ceiling up a foot. One question: is it necessary to use a tie on every rafter? I'm sheet rocking the ceiling so I don't want to space them too much, but every rafter seems excessive.
 
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Old 10-15-14, 01:50 PM
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5/8" sheet rock requires 24" centers on the structure (or less, of course) while 1/2" rock needs 16" OC.
 
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Old 10-15-14, 01:53 PM
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On a side note: a very reputable lumber yard in my area advised against placing a ridge beam under the the ridge board. I informed him that the rafters would be sitting directly on the beam, but still thought it was a bad idea.

What started out as just pushing my kitchen out a little into a back room has become a major pain in my arse. All I wanted to do was to add a few cabinets and some extra elbow room! Lol. The floor was only 2x8s, so I had to reframe the floor.

I wish I had the money to pay someone gut the room, but that's just not in the cards. I make cabinets. I'm going to just stick to that in the future. Lol

Thanks for all your advice.

Tack.
 
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Old 10-15-14, 02:12 PM
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Thanks, Mitch. The rafters are 16" on center. I just thought adding a 2x6 tie to every one of them would add excessive weight to the roof. I will of course be using strapping for the drywall.
 
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Old 10-15-14, 02:17 PM
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Sorry, mis-read your question
 
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Old 10-15-14, 02:29 PM
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Would skipping every other rafter give me too much bounce in the strapping? Pretty sure I'll be going with 1/2" Sheetrock. I'm hiring someone for that job : )
 
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Old 10-15-14, 04:36 PM
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I know I tend to overbuild, but I was going to suggest two joists per rafter, one on each side. Remember, these are not just holding up the ceiling, but holding the walls together. If you go with one per rafter, 16" on center, make sure you check the wall spacing and fasten them well. Also, make sure the existing rafters, probably with a birds mouth cut, are securely fastened to the top plate.

Moving up a foot has the advantage of making the install very easy. If you go with 16" on center you might not need the strapping. You will only be spanning 11' give or take. Hand pick your lumber and put a strong back across the top.

Did you toss the old ceiling joists?

Bud
 
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Old 10-15-14, 08:19 PM
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Thanks again, Bud. Yeah I trashed the old ceiling joists. I think there was only four of them anyway.

I totally agree with "more is better". I was just concerned with overloading the rafters/roof. What fasteners would you recommend to tie the 2x6 ceiling ties into the rafters? Also, would hurricane ties help at all where the rafters meet the top plate?

I really appreciate the advice. If you think of anything else that might be helpful, please let me know. Thanks again!
 
  #26  
Old 10-16-14, 03:15 AM
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I like hurricane ties, but the line of Simpson Strong-Ties has so many to select from I can't even find the pictures of what I use. Mine, the top is a mirror image of the bottom turned 90 degrees.

As for the joists I would be hitting a big box store and looking for something that would fit the location. Probably a double angle bracket, my name maybe not theirs.

Bud
 
 

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