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stlouisz

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Posts:12

07/22/2008 11:47 PM
I am trying to interpret lintel tables and am not sure of the uniform load requirement I have. The wall of interest supports only a roof. The wall has a large opening, one side is roughly 2-9" from the outside corner while the other side is maybe 9" from the bend in a 45 degree block. I have available 18" lintel depth. Does anyone have general idea of uniform load requirement in my situation? I'm wondering how feasible this design is. Also, what about the distance from the corner and 45 degree block? Any issues with this? Thanks.

icfcontractor User is Offline

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Posts:237

07/23/2008 12:32 AM
StLouisz, More information is needed, to give you a decent answer. What I can say is that 18" of concrete for a lintel properly engineered can carry a ton of weight such a bus or several cars or probably several buses. So your roof load should not be a problem. The info needed is many things such as type of roof, pitch of roof, materials for the roof, green roof or not, snow load, wind load, area of the country, any possible siesmic, thickness of the wall, size of the openings, ok a set of plans, and these are off the top of my head. I could probably guess at some like you live in St Louis, you will have 6" walls, but these are guesses and probably the best answer would come from a local engineer. ICF Contractor

Mark Fleming User is Offline

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Posts:191

07/24/2008 4:28 PM
I'm not sure what lintel tables you're trying to interpret. The IRC has lintel tables for ICF construction based on wall thickness and span supporting a framed roof. Unless your roof is something out of the ordinary (>12:12 or monstrously large), the tables tell you what you can span and what rebar to use. I don't have my copy here or else I could give you the answer. Mark

stlouisz

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Posts:12

07/24/2008 9:28 PM
Specifically, I am looking at LOGIX lintel tables. This is located in the product manual, engineering section at http://www.logixicf.com/index.php?n=library&o=main. The chart has columns for different loads on the wall starting with 400 lbs/ft and increasing by increments of 400lbs.

Chris Johnson User is Offline

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Posts:359

07/25/2008 12:01 AM
The loads you are looking at in the Logix manual are refering to the load from the roof. This information can be found on your truss drawings. If any load exceeds what Logix has calc'd, such as a girder truss with a point load of say 15000lbs an engineer will need to calc the lintel for you. No one here can calc this without first seeing the truss drawings with details and the blueprint showing the actual opening and all the information ICF contractor was inquiring about. Where is your distributor? He should be capable of helping you with this.

Chris Johnson - Pro ICF Napa, CA Come for the wine, Stay for the ICF work

yogia

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Posts:78

07/27/2008 8:41 PM
Hi stlouisz: You have a number of meaningful responses ... all alluding to the fact that you need to consider various things -- and if I may reiterate ... 1) span of the lintel 2) loading on the lintel ... uniformly distributed load (udl) and/or point load(s) on the lintel 3) effective depth of the lintel ... that is easy since you have the total available depth for the lintel 4) the width of the lintel concrete so if it meets the prescriptive design requirements (most likely in Block Manufacturer's Tables), you select the reinforcing steel required at bottom, nominal steel for top, the required number of ties and the size of the tie bar, the Grade of Steel (e.g. 60 ksi), and the 28-day compressive strength of concrete (e.g. 4000 psi) If you are outside the range of prescriptive design, then a Structural Engineer will design the lintel for you ... which essentially means he will compute and provide you the information in the preceding paragraph.

Regards! Yogi Anand, D.Eng, P.E. Energy Efficient Building Network LLC http://www.energyefficientbuild.com

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