Q&A / 

Column and Beam Construction

I can tell you for a fact that every week I get an email from some adventuresome person who is in the midst of or contemplating a structural modification to their abode. They want me to size a beam for them. My answer is ALWAYS the same...... Call a structural engineer!

The reason for this is simple. For one thing, each situation is different. The loads above the beam location can be significant or there may be very little load. The column locations at each end and under the beam are critical as well. Columns concentrate beam loads. These concentrated loads must rest on solid materials. A rookie often forgets this vital aspect of beam construction.

Typical Beams

There are seven common beam materials. Some are lumber products, some are steel, and others are combinations of the two. A simple beam that most people forget about is a traditional floor joist. In fact a floor system is simply a collection of beams that span between two points. Beams that we place in walls often combine one or more pieces of lumber to increase the load carrying capability of the beam.

Beams are complicated beasts. When you use lumber, not all lumber will support the same weight. Douglas Fir lumber is stronger than hemlock for example. There are vast beam sizing tables that allow you to size lumber according to its species and grade. Leave this to professionals. Don't try to do it yourself.

My own home contains three different types of beams. I have 12 inch high W12 x 31 steel I beams in my basement. The 12 stands for how many inches high the beam is. The number 31 stands for how heavy the beam is for each foot. In this case it weighs 31 pounds per foot.

I also have some neat laminated veneer lumber beams that support second floor exterior walls. These beams are basically 1 and 3/4 inch thick pieces of plywood. I also have traditional built up beams where I have nailed two or more 2x10's or 2x12's together to create a header over an opening for a doorway or a window.

There are also four other beams you can use. You can purchase fancy laminated lumber beams. These are made by gluing 2x material on top of one another. Imagine stacking 10 or more 2 x 6's on top of one another. These beams can be made to enormous sizes and can often be seen as architectural beams in public buildings. We have them exposed in my church.

You can also use a giant sawn timber as a beam. These are found in post and beam construction or a simple log home.

Imagine taking a 1/2 inch steel plate and putting it between two 2x10's. This is a flitch beam.

You can make a simple box beam by taking plywood and nailing and gluing it to 2x4's or 2x6's. This is called a box beam. I don't like using these unless an engineer calls for it.

The strongest of all beam materials is steel. You can span greater distances given the same beam height using steel in lieu of any other material.

That is why I chose to use 12 inch high steel beams in my basement. I don't have steel columns every nine feet in my basement. My steel beams span 15 feet or more without support.

To make sure I didn't hit my head in the basement, I also poured nine foot four inch high foundation walls. This gives me plenty of clearance under my steel beams.

Related Articles:  Removing a Load Bearing Wall, Column to Beam ConnectionBeam InstallationHeaders, Beams and Wall Sensors


10 Responses to Column and Beam Construction

  1. sir,
    I have query regarding construction of pillars in a house which was not constructed with pillars. Can we construct pillars in house that has no pillars?

    • Yes you can! The thing I can't tell you, is HOW MUCH weight that beam will support and not fail! You need an engineer to help you. It's all a function of the wood species, grade of lumber, etc. Don't guess or else the beam may fail.

  2. Hi i have a question regarding columns and beam. im building a house. I already have signed plans for it but im just curious. I have 6 columns all on the sides some at 3m and some at 6m apart with no column in the middle of the house.. and on the 2nd floor the slab is extended .5m and 1m on some location. When i saw the plans, i saw that the beams for the 2nd floor are located on the outer part of the slab. Meaning its is .5 and 1m away from the column. Then the planted columns are all on top of the beam ( .5 to 1m away from column). And also the planted columns will carry the weight of the roof beams and roofing.. My question is is this structuraly safe? Thanks in advance.

    • Joe,

      The only way one can answer this question is to do structural calculations after looking at the plans. I could just guess from thousands of miles away, but that wouldn't be prudent.

  3. Thanks tim.. to be honest i dont do structural calculations. Im not sure if i can.. would you design sometjing like that? Is there like a common practice or anuthing? Thanks

  4. Hi Sir, I had 2 questions to ask you, I had a single floor house,I want to make it as duplex one by cutting the slab at safe area, my 1st question is that, can i cut the slab, if i cut so, will it be structurally safe for minimum 20 years. And my 2nd question is that can we I construct walls on 1st floor without columns. Thanks in advance

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