Liviu
New Member
Posts:36
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| 11 Aug 2009 10:34 AM |
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It is possible to build a four stories apartment style building using SIP's? Any photos available? Does it require any special framing or reinforcement? |
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JeffD
Basic Member
Posts:282
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| 12 Aug 2009 07:19 PM |
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Liviu,
A SIP wall four stories high carrying three floors and a roof would be very over stressed. The way to do it is let the SIP carry the roof and fourth floor, but carry the second and third floor on a ledger wall. This will take a great deal of the load off the SIP wall. The SIP wall should be tied in to the ledger wall and/or each intermediate floor. This will brace the bottom half of the SIP which will theoretically want to bow out.
I think the best configuration is to build the ground/first floor level with ICFs and go the other three stories with SIPs, using a perimeter ledger wall at the second floor to carry the third floor. Again the fourth floor and roof would be carried by the SIP wall. The SIPs would then be a more manageable length. In either of the above cases the SIPs are the support structure unlike a curtain wall/cladding SIP configuration. This is an efficient way to use SIPs in a multi-story building because it reduces the need for perimeter columns and beams to support the roof and top floor.
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| Metal SIP Building Designer<br>jeff@panelfusion(dot com) See us on Facebook |
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Alton
Veteran Member
Posts:2164
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| 12 Aug 2009 09:08 PM |
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Jeff,
I do not quite follow you when you say ledger wall. Is there some other name for this or do you have a detail that shows this? Do not go to the trouble to draw one just for me but if you already have one then I would love to see it. The only picture that I am getting is balloon framing. My e-mail address is below. |
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Residential Designer &
Construction Technology Consultant -- E-mail: Alton at Auburn dot Edu Use email format with @ and period .
334 826-3979 |
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brucew
New Member
Posts:13
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| 12 Aug 2009 10:10 PM |
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The axial load rating of a 6.5" R Control SIP is 4000 pounds per linear foot.
Here is my math for a 40'x40' square building a 4 stories. I am using a square building since it has the least amount of linear wall per square foot of floor.
Each story is 1600 square feet. With 40 pounds per square foot live load and another 10 of dead load that is 80,000 pounds per floor.
Assuming the first floor is on a slab and the three above are resting on the SIP wall those floors would place a total load of 240,000 pounds on the external walls if no inner load bearing walls are used. Divided by the 160 linear feet of external wall this is a axial load of 1500 pounds per linear foot. The SIP panels themselves would add another 22,400 pounds or 140 pounds per linear foot.
This totals 1640 pounds per linear foot on the first floor sips decreasing with each level. It seems to me that there is plenty of room left for roof other building components while staying below the 4000 pound per linear foot axial load rating.
I have no idea what the roof of such a building would weigh but the truss chart on the 40'x44' house I am building shows a total live + dead load of about 84,000 pounds or 525 pounds per linear foot.
It seems like a 4 story SIP building would be possible to me. |
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Sip Supply Inc
New Member
Posts:44
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| 13 Aug 2009 05:22 AM |
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The real glitch is the panel length of 35ft. or taller, which most panel companies cannot do.
We can supply panels up to 53ft. tall, so if the engineering checks out it would be a possibility, depending on other engineering factors, wind, snow or seismic loads. we have done 3 story walls as tall as 36ft. balloon framed. |
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| [email protected] |
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JeffD
Basic Member
Posts:282
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| 13 Aug 2009 08:14 AM |
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Alton,
Ledger wall means a structural wall built inside the SIP wall to bear the floor system above. Stick building this wall would be great for running the buildings electric & plumbing systems. |
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| Metal SIP Building Designer<br>jeff@panelfusion(dot com) See us on Facebook |
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JeffD
Basic Member
Posts:282
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| 13 Aug 2009 08:40 AM |
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brucew,
I would be more concerned with lateral loads with a building of that height. I am really coming from from a metal SIP point of view with my conservative approach, but conceptually a metal or wood SIP is the same. In my opinion with a wall of that height and with lateral and axial loads one is expecting the first 12" of SIP skin from the foundation up to stay bonded to the foam and to not shear or buckle. A SIP could very well do it, but I would take a more conservative approach. If you did go the full height with a SIP I would use more than average internal shear walls to almost completely eliminate any lateral movement of the SIP envelope.
Also, just think what would happen to an OSB SIP if there were any hidden moisture issues at the base of the wall. Good engineering takes many issues into consideration. And to be fair a metal SIP is more likely to be over stressed in the above case than a wood skinned SIP.
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| Metal SIP Building Designer<br>jeff@panelfusion(dot com) See us on Facebook |
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Alton
Veteran Member
Posts:2164
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| 13 Aug 2009 11:55 AM |
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Thanks everyone, I understand the issues and concepts much better now. |
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Residential Designer &
Construction Technology Consultant -- E-mail: Alton at Auburn dot Edu Use email format with @ and period .
334 826-3979 |
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Liviu
New Member
Posts:36
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| 13 Aug 2009 01:08 PM |
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Jeff,
The other reason I posted this question is because we want to make the SIP using MgO panels. I see the only way of building without problems to be using a separate supporting frame and use the MgO SIP panels to complete the envelope. This way I think we can go even higher than for stories. Who would be somebody that knows how to design those type of metal/wood framings?
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wes
Advanced Member
Posts:810
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| 13 Aug 2009 02:54 PM |
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I would think that if you are building a structural frame of wood or steel to carry the loading of the building and its inhabitants, then the SIPS become simply insulating skins. This has been done quite often with timber frame and post frame buidings. Also, consider the steel clad insulated wall and roof panels made by several different companies for use with red iron steel structures.
If you take the 'structural' out of the panel requirement, then most any building company could handle the project for you. Check with a local commerical design/build firm, or if you prefer wood frame, check with some of the bigger companies, such as Morton or Stockade.
I, personally, have designed 2 story projects using the Stockade framing system, and don't see why taller projects would not be possible.
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| Wes Shelby<br>Design Systems Group<br>Murray KY<br>[email protected] |
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JeffD
Basic Member
Posts:282
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| 13 Aug 2009 07:42 PM |
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Liviu,
Structural engineers familiar with multifamily residential buildings would know how to frame a building of that sort.
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| Metal SIP Building Designer<br>jeff@panelfusion(dot com) See us on Facebook |
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cmkavala
Veteran Member
Posts:4327
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Bruce Frey
Basic Member
Posts:429
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| 19 Aug 2009 05:11 AM |
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Posted By brucew on 08/12/2009 10:10 PM
The axial load rating of a 6.5" R Control SIP is 4000 pounds per linear foot.
Here is my math for a 40'x40' square building a 4 stories. I am using a square building since it has the least amount of linear wall per square foot of floor.
Each story is 1600 square feet. With 40 pounds per square foot live load and another 10 of dead load that is 80,000 pounds per floor.
Assuming the first floor is on a slab and the three above are resting on the SIP wall those floors would place a total load of 240,000 pounds on the external walls if no inner load bearing walls are used. Divided by the 160 linear feet of external wall this is a axial load of 1500 pounds per linear foot. The SIP panels themselves would add another 22,400 pounds or 140 pounds per linear foot.
This totals 1640 pounds per linear foot on the first floor sips decreasing with each level. It seems to me that there is plenty of room left for roof other building components while staying below the 4000 pound per linear foot axial load rating.
I have no idea what the roof of such a building would weigh but the truss chart on the 40'x44' house I am building shows a total live + dead load of about 84,000 pounds or 525 pounds per linear foot.
It seems like a 4 story SIP building would be possible to me. In your example, how would you frame the floor systems to distribute the weight evenly on 4 sides? The only way I can think of is a 2way waffle slab.....which at 40' span will blow away your DL theory. If you use bar joists or similar, your slab loads will be basically be taken by 2 of the 4 walls, doubling the load. The hard part is going to be dealing with wind/seismic/lateral loads. Building a real structure and cladding it seems the most logical way to go. Bruce |
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brucew
New Member
Posts:13
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| 19 Aug 2009 11:27 AM |
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Posted By Bruce Frey on 08/19/2009 5:11 AM
In your example, how would you frame the floor systems to distribute the weight evenly on 4 sides? The only way I can think of is a 2way waffle slab.....which at 40' span will blow away your DL theory. If you use bar joists or similar, your slab loads will be basically be taken by 2 of the 4 walls, doubling the load. The hard part is going to be dealing with wind/seismic/lateral loads. Building a real structure and cladding it seems the most logical way to go. Bruce Use steel trusses to support the floors and roof. Alternate direction with each set. The first floor is the slab, the second bears on walls 1&3, the third bears on walls 2&4, the fourth bears on walls 1&3 and the roof bears on walls 2&4. I thought SIPS were great at handling Seismic and Lateral loads?
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Bruce Frey
Basic Member
Posts:429
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| 21 Aug 2009 08:11 AM |
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Posted By brucew on 08/19/2009 11:27 AM
Use steel trusses to support the floors and roof. Alternate direction with each set. The first floor is the slab, the second bears on walls 1&3, the third bears on walls 2&4, the fourth bears on walls 1&3 and the roof bears on walls 2&4.
DUH! That is what happens when you don't take off your "large project" hat! About the only structural walls I am used to are shear walls. I still think at 4 stories SIPS will be problematic as a structure. Just because you can do something does not mean that you should. Bruce |
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Jerry D. Coombs, PE
Basic Member
Posts:138
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| 24 Aug 2009 05:38 PM |
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I see no reason why this couldn't be done if you want to do it. Stranger things have been done quite successfully. Though I don't have a clue what your floor plan is like, I expect it could be made to work well without the expense of a complete building and using the SIP only as a cladding. Lateral loads can be dealt with in many ways.
You just need the right architect/engineer team working together on it. Doesn't hurt to have the contractor in on the design stage either. |
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Jerry D. Coombs, P.E.<br>Coombs Engineering, P.C.<br>
<br>You can have with quality; You can have it fast; You can have it cheap.
Pick any two. |
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SimonD
Basic Member
Posts:113
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| 29 Aug 2009 06:30 PM |
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Thought about this concept for a while. Graduating the wall panels as you go up to create a ledger for the floor system and to reduce weight. The first floor wall SIPs could have heavier engineered lumber for splines/plates and be moment connected to the foundation and the reinforcement would get lighter as you went up. This wall/floor configuration is very rigid and gives the floor system the bearing that it needs. This is just a 'raw' concept. There are many issues to consider such as thermal bridging, fire code and such. |
 Attachment: 4 Story SIP Concept.jpg
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| Building Designer<br>PANELfusion, LLC, Tampa, FL<br>simon@panelfusion(dot com)<br>"Metal SIP Advocate" |
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Alton
Veteran Member
Posts:2164
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| 29 Aug 2009 06:54 PM |
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Simon,
I see that you have only 2" of bearing for the floor trusses. A normal floor truss usually has at least 3" of bearing. I believe that a bearing can be less than 3" but I thought the floor truss had to be reinforced to do so. What are your thoughts about this. |
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Residential Designer &
Construction Technology Consultant -- E-mail: Alton at Auburn dot Edu Use email format with @ and period .
334 826-3979 |
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SimonD
Basic Member
Posts:113
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| 29 Aug 2009 11:47 PM |
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Alton,
I guess my drawing implies wood construction and therefore the use of wood floor trusses. Bearing depends on load, span, deflection limit, on center spacing, design of the truss end and method of attachment, so as long as these variables are taken into consideration two inches of bearing is not unreasonable. I would probably go with some kind of light gauge steel framing which would be lighter and can tolerate less bearing. Actually, I drew my concept in 'wood frame', but a system in steel with steel SIPs is the way I would go. All your framing members could be the same depth and you could theoretically just vary the gauge of the steel, lightening it as you ascend. |
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| Building Designer<br>PANELfusion, LLC, Tampa, FL<br>simon@panelfusion(dot com)<br>"Metal SIP Advocate" |
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brucew
New Member
Posts:13
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| 30 Aug 2009 10:21 AM |
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You can hang the floor trusses on the inside of the walls without any bearing on top of the sips or place the trusses on top of the SIP below and under the SIP above giving it full width bearing. I can not see any issue with the trusses.
I am curious if you believe there is a need for larger SIPs at the bottom, or used them to create a ledge for the trusses? According to the specs it looks like 6.5" SIPs would be strong enough to me. |
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