Removing a 4 foot opening in a load bearing wall (for fish tank)

Hello all,

I am trying to build a fish tank into a load bearing wall and want to make sure I take all necessary precautions.

The fish tank wall used to be the exterior wall of the house before an additional laundry room was added on a few years ago. Now it is the wall separating the kitchen from the laundry room. There is a story above it and the wall above is actually the exterior wall of the house. The wall below in the basement is a concrete foundation wall (there is no foundation below the laundry room). The fish tank wall is plaster with standard studs and is 12' tall.

I want to remove basically a 4' wide by 22" tall opening from the center of the wall, starting at about 42" high. First, is this a horrible idea? Second, is it possible to do myself, or would that also be a horrible idea? Finally, if I did do it myself, how would I support the wall while installing the double header and studs to frame out the hole for the tank?

First, since you are cutting into a load-bearing wall, you need to contact your local building inspector to see whether you need to submit plans and take out a permit. You may think this is not important, but just wait until you try to sell the home and have to answer questions on the disclosure form. You will either have to lie and risk lawsuit, should something go awry, or you will have to admit to having made alterations to the home without a permit, thus risking lowering the value of your home. Many locales only require a permit when you are cutting into load-bearing walls.

Before you start cutting, make a small observation hole, so you can check for wiring and plumbing.

Secondly, set up a support under the kitchen ceiling within a foot or so of the wall you will working on, by supporting a length of 2X6 flat against the ceiling on top of three or four 2X4 studs standing on the floor. Wedge the 2X4s tightly against the 2X6 to support the ceiling, to carry the weight while you are working on building a header over the opening for the aquarium. Once that is done, and if no wiring or plumbing interferes, mark out your cut and cut away with a reciprocal saw (rent one). Easy as pie.

For the header for a 4' opening, you should use two 2X6s (or 2X8s if you want) on edge with a piece of 1/2" ply or osb sandwiched between them. Use construction glue (Liquid Nails) and nails to put the sandwich together. Support the header with a stud and two cripples on each end (the header butts into the full-height studs on each end and the cripples are the short studs that support the header underneath. The rule of thumb is that you support the header with at least the same number of cripples as the studs you cut out for the opening.

You will need to add short blocks above the header, as well, to support the top plates (If you measured and planned well when you made your first cuts, you probably have short pieces of the original studs hanging down and you can just install your header under them). Locate them in the same place the studs were.

Depending on the size of the aquarium, if it will be built into the wall, it may be a good idea to build a header under it as well, or better yet, a stout cabinet, since an aquarium full of water is pretty heavy. While you have the area under construction, you might look at running a new outlet into the cabinet for your pump, heater, etc for the aquarium. Make it a GFCI outlet for safety.

Have fun.