Removing a Load Bearing Wall
DEAR TIM: I want to remove a large portion of the wall that separates my living room and kitchen. I am certain it is a bearing wall. Is this a job I can tackle? How do you size and install the new beam that will replace the old wall studs? How do I figure out if there are pipes, wires, and ducts hidden in the wall? Sally O., Millers Tavern, VA
DEAR SALLY: You better get out your surgeon's gloves, dust mask, X-ray equipment, and hard hat for this procedure. Structural alterations such as you have planned will involve possible triple utility bypass surgery and major amputations of several limbs that hold portions of your house upright. If you obtain a plan developed by a registered residential structural engineer, I believe you can tackle this job with a little help from a few friends.
Load bearing walls often run perpendicular to the run of floor or ceiling joists that rest on top of the wall. However, beware of walls that run parallel with floor joists. They can obscure hidden posts or columns like two that I have in my own home. You can create an opening in a bearing wall much the same as openings are created in exterior walls for large windows or doors. A beam is placed over the new opening. The beam accepts the load from above and concentrates it onto columns or posts at either end of the beam. The new columns or posts that support your new beam must rest upon solid bearing material. The weight of the structure above the beam will then be transferred to a spread footer, thickened slab, steel or wood beam, or possibly some other structural member below.
Sizing the beam and the posts that support the beam should be done by a professional. A structural engineer is trained to calculate the current floor, ceiling and roof loads and possible added loads caused by snow, attic storage, and additional roof coverings. If you undersize a beam, portions of your house can sag and even in extreme cases collapse. The fee to hire an engineer who can develop your re-support plan is minuscule compared to the cost of repairing structural damage after a collapse.
There are several different ways to install a new beam in a load bearing wall. In some instances you can hide the beam within the ceiling above. This works only if the beam height does not exceed the height of the floor or ceiling joists and there are no utilities that must pass through the new beam location. If you choose this method, the floor/ceiling joists above are attached to the new beam using metal joist hangers.
The most common approach is to install the new beam below the floor/ceiling joists. To install the beam you need to build a temporary support wall on either side of the wall you are removing. Hold the temporary walls back about 30 inches from each side of the old wall. This will give you room to work. Be sure to build your new beam and slide it up against the old wall before you build your last re-support wall. If you fail to do this, it is often impossible to get the new beam into position (the voice of experience talking......).
Just about every bearing wall has utilities buried within it. It is not uncommon to find plumbing supply and waste lines, heating and cooling ducts, electrical wires, and low voltage wires for telephones, doorbells, and intercoms. It is possible to relocate these utilities in almost every case, however, it may be time consuming, costly, and require extensive additional demolition.
You can often see where these utilities enter the bottom of the wall in a basement. In some instances, wires and plumbing vent pipes might be visible in an attic as they rise up from the bearing wall. Your best bet is to use an electronic device made specifically for this purpose. You can purchase hand held devices with a liquid crystal screen that will show you studs, hidden pipes, wires, conduits, and duct work. These units can "see" through plaster, drywall and wood.
If you choose not to use a device like this, simply peel away the covering on one side of the wall and see what hidden surprises you find. If you are lucky you will discover an old hidden "contractor" time capsule. I placed one of these on each of my jobs. My time capsules contain a newspaper from that day, rinsed out soda cans or bottles, and other package wrappers. It is fun to read old ads about how you could once buy milk for 29 cents a gallon or a new car for $800!