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Thread: Raising the ceiling
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02-17-2009, 04:23 PM #1
Raising the ceiling
Someone asked my opinion about this installation.
Background
Single story ranch house, attached garage
Owner installed a car lift to park his collector car above his daily driver in one of two garage bays (two car garage with two garage doors).
Raised the ceiling in the garage to allow clearance to lift collector car above daily driver.
Thoughts? He cut the ceiling joists (looks like 6?), added double 2 x 12s to form the perimeter.
What came to mind for me was, probably no worse than a vaulted ceiling.
Appreciate any feedback.
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02-17-2009, 05:31 PM #2
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02-17-2009, 05:57 PM #3
Re: Raising the ceiling
My question would be what did they do to replace the rafter ties (ceiling joists) that they cut?
There needs to be something there to resist rafter thrust or the ridge needs to be designed as a beam.
I don't see anything there to tie the sides of the building together.
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02-17-2009, 06:07 PM #4
Re: Raising the ceiling
I would ask to see approved engineering drawings and see original permit with final approval from local building authority.
Joseph, Palm Bch County, Fl.
HomeSafeSouthFlorida.com
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02-17-2009, 06:39 PM #5
Re: Raising the ceiling
The roof is tied in when he reframed it with the 2x12s and then built the wall on it and then added new ceiling joist that I would asume are tied into the roof rafters. Collar ties further up on every forth set of rafters at the minimum would be in order.
Again. I cannot see it all but what appears to have been done from this very long distance away does not bring to many questions to mind.
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02-17-2009, 07:13 PM #6
Re: Raising the ceiling
There should be rafter ties every 4' minimum since the ceiling joists are no longer there.
Collar ties won't do it. I see this all the time in new construction and just shake my head.
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02-17-2009, 07:15 PM #7
Re: Raising the ceiling
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02-17-2009, 09:29 PM #8
Re: Raising the ceiling
Correction, the ceiling joists are no longer there doing the job of rafter ties.
There is no continuous tie across the building.
(of course Jerry knows this, he is just trying to elevate the level of the conversation)
Since I don't have the code available to cut and paste, I will leave that to Jerry.
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02-17-2009, 09:37 PM #9
Re: Raising the ceiling
Jim,
The ceiling joists do not have be "continuous", they can meet on a bearing wall and be attached to each other (the old fashioned way of doing it).
Or they can meet on a beam, girder or effectively what amounts to one of them and be attached with hangers and nails, the way shown in that photo.
I was not trying to elevate the conversation, I was trying to get you to review those photos again and see that there is an effective path from one wall to the other through the ceiling joists, no rafter ties needed.
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02-17-2009, 09:48 PM #10
Re: Raising the ceiling
This is from the 2003 IRC that I had on hand, likely the same for later editions, underlining is mine:
IRC-2006 (all new section in 2006)
R802.3.1 Ceiling joist and rafter connections; Ceiling Joists and rafters shall be nailed to each other in accordance With Table R802.5.1(9), and the rafter shall be nailed to the Top wall plate in accordance with Table R602.3(1). Ceiling Joists shall be continuous or securely joined in accordance With Table R802.5.1(9) where they meet over interior partitions and are nailed to adjacent rafters to provide a continuous tie across the building when such joists are parallel to the rafters.
Where ceiling joists are not connected to the rafters at the Top wall plate, joists connected higher in the attic shall be Installed as rafter ties, or rafter ties shall be installed to provide a continuous tie. Where ceiling joists are not parallel to rafters, rafter ties shall be installed. Rafter ties shall be a minimum of 2-inch by 4-inch (51mmby102mm) (nominal), installed in accordance with the connection requirements in Table R802.5.1 (9), or connections of equivalent capacities shall be provided. Where ceiling joists or rafter ties are not provided, the ridge formed by these rafters shall be supported by a wall or girder designed in accordance with accepted engineering practices.
Collar ties or ridge straps to resist wind uplift shall be connected in the upper third of the attic space in accordance With Table R602.3 (1). Collar ties shall be a minimum of 1-inch by4-inch (25 mm by102 mm) (nominal), spaced not more than 4 feet (1219 mm) on center.
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02-17-2009, 10:02 PM #11
Re: Raising the ceiling
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02-17-2009, 10:44 PM #12
Re: Raising the ceiling
I just don't see the same load path Jerry. Envision your colored lines as a string and pull on both ends. Do you see any room for the vertical slack to come out of that string?
That continuous tie that the code mentions seems to be broken by a vertical offset which can rotate. I know the joist hangers are rated for bearing load, but what about tension?
That ceiling looks plenty strong to support the weight, but I doubt the ability to resist tension.
It does not meet the requirement of a continuous tie across the building, that is one ceiling joist supported by a hanger on the side of an intersecting beam and another separate joist coming from the other wall meeting at an offset in the middle. Those joists are not lapped or nailed to each other.
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02-18-2009, 08:06 AM #13
Re: Raising the ceiling
Jim,
I see enough 'meat' in that framing to resist the load which need to be resisted for the length it needs to be resisted - don't forget, there are triple or quad members on each side of that box, and that box is not that long, maybe 10 feet long, with those full length triples/quads on each end, thus you are only dealing with about the center 6-8 feet of the load.
I see "way more" strength in there than would be needed to resist that load for a measly 6-8 feet.
I would agree with you if that was for the full 20 length of the garage, but even then the solution would be simple: add diagonals from the top of the knee wall down to the joists, creating triangulation, then that step up would not rotate at all.
But for that measly 6-8 feet? Looks plenty strong enough to me.
That is "to me" and "for me". As a home inspector, though, I am looking at it *not* "to me" and "for me", but "to me" and "for my client" - big difference, with that difference being "liability". "To me" and "for me" means *I* accept the liability for it and *I* will address it should it become a problem, however, "for my client" that becomes an issue where *I* do not want to accept the liability for it at some future point in time.
Thus, my solution for conditions like that was to "have structural engineer design appropriate repairs". If the structural engineer comes down and signs and seals a letter stating that "as built" is acceptable, the engineer was not for naught, my client *now has an engineering letter stating it is okay*, and they put that letter in their house file for when they become a seller, and (as someone else here suggested previously) hand a copy of the letter up there so anyone questioning it can read it.
"To me" is looks sufficient to resist those loads in that limited area.
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02-18-2009, 08:27 AM #14
Re: Raising the ceiling
Again, well stated by Jerry. Get signed and sealed along with Building Permit.
From my understanding owner of record bears future liability if work was done without PERMIT.
Joseph, Palm Bch County, Fl.
HomeSafeSouthFlorida.com
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02-18-2009, 09:31 AM #15
Re: Raising the ceiling
...even then the solution would be simple...
Simple solutions are usually better, at least in my world.
If it does not meet the intent or the letter of the code, call it out.
Then the person responsible can either make it meet the letter and intent of the code (likely less than 200 bucks labor included) or call for an engineer to sign off (likely 200-300 bucks) and maybe have to do the fix anyway.
I understand your personal opinion about it being plenty strong and not likely to go anywhere and if I saw this in an existing house with some time on it (5-10 years) I would not mention it. Evaluating from those pictures on a fresh job though, no way "I" would bless it.
Last edited by Jim Luttrall; 02-18-2009 at 12:03 PM.
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