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What's A Ridge Beam Support Column?
By George Porter
If you are an up-to-date installer of manufactured housing,
you are well aware of what a ridge beam support column is and
what it does. If you don't know what it is, don't feel too badly.
You've got a lot of company. And in your defense, how could you
know if no one ever told you.
What we're talking about is a point within the marriage wall
of a multi-section home that helps support the roof. If the home
has a large open room going from one side of the home to the other
through the marriage wall section, then the roof must be supported
by a beam along the ridge of the roof. Obviously since there is
no wall a strong beam has to be engineered that will not allow
the roof to sag in the area of the open room. This beam is also
to be supported by structures within the wall called the ridge
beam support column. There are generally three or more studs connected
together that are found on each end of the open span at the marriage
wall. The ridge beam is like a bridge and these column supports
support the ends of the bridge. They transmit the weight of the
structure plus the roof load, such as snow, through to the foundation
beneath.
The weight this column is designed to hold could be three times
or more the weight found on a pier under the I-beam. The length
of the ridge beam determines how much load each one of these built-in
supports has to carry. A very small room will have far less load
than a very large room. Think of it as if you layed concrete blocks
end to end along the roof ridge. The only thing that holds those
concrete blocks up are the ridge beam and its support columns.
The longer the span, the more concrete blocks, the more weight.
Consequently, not all homes will have the same load to bear. Different
size loads require different pier capacities, as well as footing
sizes. If you put too large a load on too small a footing, it
will sink.
Footings are a major topic to be covered at a later date, but
for now, we'll just say that if the load under the ridge beam
support column is three times larger than the load under the main
I-beams, then obviously the footing needs to be three times as
big.
This misunderstanding, or lack of knowledge, about the ridge
beam support column has bestowed upon our industry long term problems
of a large magnitude. It's the kind of problem that usually doesn't
show up within the warranty period, although it's certainly possible
if in fact there is no support there whatsoever. If you have 10,000
to 18,000 pounds of weight within the home that is unsupported,
you will eventually have a problem. Gravity always wins.
It is absolutely necessary to have the pier directly beneath
the ridge beam support column. The farther it is away from that
point, the sooner the problem will occur, and the worse it will
be. If you miss that point by a foot, it may be years and years
before the problem surfaces. If you miss it by six feet, you will
probably have the problem within the same year, depending upon
the roof load in the area where the home is located.
When the pier is not directly beneath the supports built into
the wall, the pier is trying to push its way up through the floor,
and because of the weight of the home and roof load, the ridge
beam support column is trying to push its way through the floor
in the other direction. It's easy to understand how this can cause
a problem.
How do we make sure this does not happen? First of all, we
need the cooperation of the factory that built the home. In order
to put the footing in the right place, the factory will need to
send us a footing plan showing the exact location of each pier.
A generic foundation plan will not do, because there are as many
placements of ridge beam support columns as there are interior
designs of homes. You will be able to figure it out when the home
arrives, but you might want to be sure your foundation is ready
before that. Adding a new footer after you've already got the
foundation poured is not very convenient. Blocking that particular
pier on top of the ground while the rest of the home is sitting
on frost protected footings is a very bad idea.
The first good idea you should get is to call the factory and
ask them, "how could this possibly happen when you followed
their plans so closely." Have them compare the foundation
plan they sent to the floor plan of the home they sent you. Find
out why this problem occurred. Don't be too mad at the factory.
You'll probably be the first person to have ever called and brought
it to their attention and it would be hard to believe that there
would exist a factory in today's world that would not appreciate
it. The communication between installers and factories is all
too infrequent. Factories cannot know there is a problem if installers
do not tell them, and installers will continue to live with that
problem unless they tell the factory. And, as you well know, there
are a few problems out there. Over the coming months we will be
discussing these problems in this column. Any input or suggestions
you may have can be mailed directly to me, George Porter, P.O.
Box 9, Nassau, Delaware 19969.
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