Replies

1. 
   FastEddie | May 19, 2006 12:01am | #1

   Experience helps a lot.   Go up in the attic and see if the ceiling joist run across the partition wall, or parallel to it.  That's a start.  post pictures here if you can.

    

   "When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it."  T. Roosevelt

2. 
   maverick | May 19, 2006 12:34am | #2

   You might find a clue in the basement also, if its a bearing wall it should have a some beefy support under it

3. 
   Piffin | May 19, 2006 01:38am | #3

   Is your roof and cieling stick-framed or trusses?

    

    

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4. 
   JohnSprung | May 19, 2006 03:25am | #4

   Here's a FAQ I wrote on the subject a while ago:

   How to identify bearing walls:

   When somebody asks how to identify load bearing walls, it's usually because they're thinking of removing a wall or cutting a big hole in one.  That can be serious business, not something that can be designed adequately by using a FAQ from the internet.  The following discussion may be useful for the preliminary speculation phase of such a project,
   but don't rely on it for anything more.

   Removing a load bearing wall is not impossible, but it is more
   expensive.  Often much more expensive.  It will require some sort of substitute support for the weight it carried, usually a beam.  Often this beam will have to be large enough that it extends downward from the ceiling fairly far.  On a top floor, you may be able to hide it in the attic, and hang the ceiling joists from the side of it, or even from the bottom.  But often the ugly beam sticking down, which always looks like you took out a wall, defeats the architectural purpose of removing the wall in the first place.

   You'll also have to provide adequate support under the ends of the beam, because the load that was formerly distributed along the length of the wall is now concentrated there.  This load has to be supported all the way down to the ground.

   The official code definition of a bearing wall is any wall that
   supports 100 pounds or more per foot of length, and any masonry wall that supports any additional masonry above its ceiling level.  That's not particularly practical or helpful, since there's no instrument to measure the weight on the top plate of a wall.

   In general, you have to look at what the wall supports, and what
   supports it.  Walls that are parallel to the joists above are usually but not always non-bearing.  On my top floor, I have a wall parallel to the joists that supports the rafter tails of a decorative roof section.  On the top floor, always look in the attic to see if the wall in question carries any roof load.  Then look to see if it supports ceiling joists.  If the joist tails rest on a wall, it's almost always bearing.  I have one exception to that upstairs, where the ceiling joist tails rest on a non-bearing 2x3 wall that was the partition between two closets, each 10 feet by 27 inches.  On each side, the real bearing walls are only 27 inches from this partition wall.  They form the sides of the stairwell.

   Taking that idea a bit farther, you may want to analyse the whole house, figuring out from the top down how the weight of all the materials and contents are supported all the way down to the ground. That's the way engineers design structures, from the top down.  They have to do it that way, because they can't design any part of the structure until they know the weight of the stuff it supports.

   In the past, certainly in the 1920's, building codes used to allow
   2x3's for non-bearing walls. Then for quite a while 2x4's were the minimum for all walls.  I know that started prior to 1971, but I'm not sure how far prior.  Now with the 2005 code, 2x3's are allowed again for non-bearing walls.  It's possible that you'll find a load bearing 2x3 wall if bootleg remodeling removed a nearby bearing wall.

   For ground floor walls, look in the crawl space or basement.  A
   bearing wall perpendicular to the joists should be no more than one joist depth away from some sort of support -- a girder or cripple wall.  That's a code requirement for all walls, not just on the ground floor.  So, if your joists are 2x10's (actually 9 1/4"), and a wall is 10 inches away from the nearest support, it's probably not supposed to be bearing.  The exceptions are if the original design was done by an engineer, or the building is old enough to pre-date that code.

   In old houses, bearing walls parallel to the joists below may have no extra support.  In newer construction, they'll usually have a joist or two under them.  The best practice is two joists with space between them for utilities to run into the wall without hacking up the structure.  As always, beware of bootleg jobs that may have transferred loads to walls that legally shouldn't carry them.

   The tough part comes when you have three or more stories, and you want to work on the in-between floors.  First, you should start from the attic and work down, because any bearing wall up there has to be supported by bearing walls all the way down.  Then look in the crawl or basement, and work your way up.  As with the crawl space, the max is one joist depth away from floor to floor, unless it's an engineered design or an old building.  Next you may need to do some exploratory demolition of the ceiling to see what's on top of the wall in question.  Again you're looking for joist tails, this time floor joist tails.

   Finally, even if a wall appears to be non-bearing, if it's perpendicular to the joists above, you have to determine the size of those joists and the new distance they'll span if the wall is removed. If there are no walls or roof load supported by those joists, you can look in the span tables to see if the result will pass code.  If they support other parts of the structure, engineering calculations are necessary.

   Most people at this point should hire a structural engineer.  If you don't want to hire an engineer, get some engineering books from the library.  Unless you have a very strong technical and math background, that kind of light reading will probably convince you to pay somebody who already knows this stuff.  Even if you have the ability to learn enough for a simple job, an experienced engineer's second opinion may well provide you with a more cost-effective solution and save you more than the engineer's fee.

   Most jurisdictions will require a licensed engineer's wet stamp on plans before they issue a permit for structural work.  So even if you could learn enough to do it yourself, your local building department may not accept it because they don't have the resources to check your work.

   What you may be able to do for yourself is measure and draw.  If you can make good accurate measurements and drawings of what you have and how you want to change it, you may find an engineer who will do your job from your drawings, without the expense of a site visit.  Some will even do simple jobs via fax.

   A general contractor or rough carpenter might also be able to give you an expert opinion on whether a wall is bearing or not.  Please don't ask for a "free estimate" if you don't intend to hire someone for the job. The fair thing to do is pay them their hourly rate.  That might be about half what an engineer would charge for a site visit.

   Also, non-bearing is merely a legal term used in codes.  It doesn't mean that the wall in question has no structural role.  Gravity doesn't care whether we call a wall bearing or not.  After it's gone, the floor above may be less solid feeling, even though it still passes code.

   (Bearing Wall FAQ revised March 12, 2003)

    

    

   -- J.S.

    

   
   

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   Edited 5/18/2006 8:26 pm ET by JohnSprung