Replies

1. 
   Jay_ | Mar 20, 1999 07:30am | #1

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   And just how much load will a double LVL 14 carry? I think you are asking a lot for us to look up 2 different materials, it would be easier if you just said what the load is. I personaly don't understand the problem, with a 3 foot overhang it seems to me you have lots of depth to work with at the location of the door. How is the roof framed?, what is it's span? I'd like to see some clarification of "local codes limit height from top of grade to top plate" does the top of the beam count as "top plate" of can the beam sit on top of the "top plate", with your overhang, the eave will be much lower than the plate (unless it's a flat roof) I'd think that there should be some leeway with the height restriction since the eave line will make the structure visualy lower that the top plate height.

   jay

2. 
   Guest_ | Mar 20, 1999 07:36am | #2

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   Triple the next size smaller lvl.

   I have done same.

   J

1. 
   Guest_ | Mar 20, 1999 09:25am | #3

   *For that matter, what about a 2 x 8 wall and even thicker beam? doesn't sound like that much extra wood.

1. 
   Guest_ | Mar 20, 1999 10:38pm | #4

   *Not necessary.

1. 
   Guest_ | Mar 20, 1999 11:00pm | #5

   *What you want to do is raise the bottom of your header. Why?If you have a 3' overhang with a 3/12 pitch, the bottom of your fascia will be 9" below the plate level. Say you use a 9" beam (you can eliminate the double top plates over the beam), then you only have 9" of clearance for your door hardware. This is not enough for a sectional door, even with low clearance hardware. So you will have to use a tilt-up type door. That will take up more of the opening space than you gained in using a smaller beam. Say your pitch is 4/12 or greater. Then your fascia will be at least 12" below the plate line. So using a smaller beam, may make the door a little larger, but you will not gain clearance since the low point will be at the fascia.

3. 
   Vern | Mar 21, 1999 07:22pm | #6

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   Clarification
   Local codes specify 8' 2" maximum from grade to top of wall plate (no consideration of eve height). The garage will be sitting on a concrete slab that itself will be 3" above grade to keep everything nice and separate (soil and framing). The total length of the bottom member of the roof truss is 24 feet, 1 foot hanging off the back, 3 feet hanging off the front to form the 3' overhang, with nothing coming below the level of the bottom member of the roof truss.(no tails) The double LVL was calculated by my truss supplier, who spec'd out either a double LVL 14" deep, or a triple LVL 11 1/2" deep. Even the triple will be too deep for this application, that's why I feel steel is a reasonable alternative. The roof will be framed with manufacutured roof trusses, 24" on center, with a standing seam metal roof, and this being southern Ontario, will be exposed to snow loads.

4. 
   Guest_ | Mar 21, 1999 07:29pm | #7

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   Vern,

   Your building department with the silly height restriction has on file all the plans they have inspected of your neighborhood's garages....And all these garages are also right there for a quick "look-see"....No need to reinvent the wheel...

   J

1. 
   Guest_ | Mar 21, 1999 09:06pm | #8

   *You still have not addressed the issue of how you intend to make a garage door work, if you reduce the clearance. Or, how you intend to get more clearance under the fascia, even if you can reduce the header size.I think someone is mis-interpreting this code requirement. Since most codes require (or should require) 6" clearance from grade to the bottom plate, this would essentially prohibit 8' walls. Throw in 6" sub floor framing and you would be limited to 7'2" walls. I don't think this is the intent or effect of this ordinance. Perhaps the restriction is the limit of the top of a stem wall or a cripple wall? Given that you still want to reduce the depth of the header, try two 8'openings with a post in the middle.

1. 
   Guest_ | Mar 21, 1999 10:20pm | #9

   *Find out from your supplier what the "s" value is for the double LVL. Then call your local steel supplier and tell them you want an economical section that will give that "s" but with a mximum of x inches in depth. This is really not an exact substitution, but will get you started. Then consult an engineer for the exact substitution.

5. 
   Fred_Matthews | Mar 22, 1999 09:45am | #10

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   Vern:

   What you are really asking for is some free engineering, which as an engineer, I would never provide in this type of forum.

   Getting an equivalent "S" value (Section Modulus) is not wise advice. Steel W or S sections are not rectangular like an LVL section, and are subject to a phenomena known as web crippling. Assuming that the section modulus is the only governing factor in selecting a member is a gross oversimplification. If you can't solve your clearance/code problem-hire an engineer. A good one will not waste your time and money and will quickly size an appropriate member for a nominal cost.

   Fred

6. 
   Vern_Cordt | Mar 22, 1999 09:45am | #11

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   I am building a garage where the roof does not run the ususal way. The gable end does not fall over the side with the garage door. Over the garage door (16 foot double) the 'eve' will overhang 3 feet to provide a bit of weather protection (and increase the loading). A header in wood (to carry the entire roof load over the span) would require a double LVL 14 inches deep, but local codes limit height from top of grade to top plate, and the header would come down too far into the door opening. Can anyone tell me what size, in either a standard "I" beam, or in a wide flange beam, would be capable of carrying the same load as the double LVL. The garage door wall will be either 2x4 or 2x6 framing depending on my options.