Load Bearing Walls
Supporting a Load Bearing Wall
Introduction:
DIY homeowners frequently
are confronted with the puzzle of dealing with load
bearing walls when performing home renovations to
their home. Typically they ask questions like; how
do I remove a section of the wall and what must be
installed to take up the load. These are very good
question and the answer is quite simple but the
work may not be as simple.
One definition of a load bearing wall is any wall
that carries the upper weight of the house through
the structure to the foundation and in turn the
foundation distributes the weight to the earth
beneath it. For example, for a house that is 40
feet long and 32 feet wide there is typically a
center beam that can be seen from the basement that
passes through the length of the house half way
between the walls (16 feet). This beam is a
structural support member that basically holds up
the middle of the house. It will have steel columns
underneath the beam at approximately every eight
feet apart.
The center beam will have the floor joist passing
over it. The joist will be 2 x 10s in this example
because of the 16 foot span. This entire floor
network supports the house above. However, located
on the first and subsequent floors are additional
load bearing walls to carry the weight of the
second floor or roof above it. Maintaining these
load bearing walls is critical to maintain the
structural integrity of the house. They cannot be
arbitrarily removed but they can be altered.
Whenever removing a load bearing wall section the
load that the section carries must be
redistributed. This is typically done by installing
a header in place of the wall section. The header
is usually made from 2 by X stock, depending on the
length. An eight foot open doorway underneath a
bearing wall would typically be made from laminated
2 x 8s for a single story house and 2 x 10s for a
doorway on the first floor of a two story house.
Before cutting out the section of wall to install a
wall header a temporary brace must be installed to
carry the load while the header is being installed.
The temporary brace can be fabricated from 2 x 4s
and stalled a short distance (12 inches) from the
bearing wall. After the header is installed the
temporary brace is removed.
Making the intended doorway opening level with the
ceiling is a little more complicated. The actual
ceiling joist must be cut to install the header.
Again temporary bracing must be installed while the
header is installed. In this case the header must
be firmly attached to the ceiling joist using joist
hangers so the bearing load can be spread out to
the adjoining joist. Although cutting into the
floor joist to install a header is quite common I
would recommend that a DIY homeowner leave the task
to a professional carpenter. However, installing a
header in an interior load bearing wall is not a
difficult task and is well within the capability of
most experienced DIY homeowners.
Related articles:
Exterior 2x4 and 2x6 Walls
Framing a Finished Basement
Framing Walls | Wall Framing Layout
Framing a Cathedral Ceiling