#Lvl support beam span table how to

Typically in basements, these posts will be structural steel, concrete or built up wood posts made from pieces of standard dimensional lumber (2 'bys') all nailed together side by side. Now we will need to support that center floor beam with posts. What if we needed to span more than that? In the table above, the widest floor beam span for 12' of supported floor joists is 14'7' (if using a 5-ply 2 X 12). Our floor joist beam can span a maximum of 13'. So we now have adequately sized floor joists and an adequately sized floor joist beam for our 24' X 13' house. Moving from Beam Calculations to Beam Supports The best place to pick up span tables is at your local lumber yard since they will have all the tables that are used in your region. You will see that a 4-ply, 2 X 12 can span a maximum of 13' while supporting 12' joists on either side of it. Look at the table along the row for 12' of supported length. We will also probably want the smallest built-up beam that will meet this requirement since this will be the least expensive one.

Since the house is 13' long, we are looking for a table entry for a built-up floor beam that can span 13 feet. So we'll read along the table row for 12 feet of supported length. Dividing by two gives us 12 feet of supported length. In the case of our example house, the house is 24 feet wide so the house will require a total width of 24 feet of joists. The supported length shown along the left-most side of the table, is the total length of the floor joists to be supported on either side of the floor beam divided by two. A 3-ply with 2 X 10s would mean that three 2 X 10s are joined together side by side with their wide sections running parallel to one another. It also shows the maximum that the beam can span for various numbers of such pieces of lumber built together (this is indicated by 3-ply, 4-ply and 5-ply). This span table excerpt shows two possible sizes of built-up floor beams (2 X 10 and 2 X 12). This table is simply a sample and may not be valid for your region. There are several beam span tables for all the species of wood. The table below shows an excerpt from a maximum span for built-up Douglas fir floor beams table for supporting not more than one floor. There are many beam span tables for all the different lumber species and also for the number of floors that are ultimately supported by this beam. The question now is how big does that center floor beam need to be? Once again, it is not necessary to do tricky wood beam calculations but rather, simply look up the answer in a beam span table. The picture below shows what the framing for this floor would look like in a three-dimensional perspective. The floor joists are still 12' long but now you can see a floor beam running horizontally across the middle of the house (supported by the lower concrete foundation wall). See the picture below for a plan view of how this will look. So we will have to place wood floor beams (or likewise, wood ceiling beams) across the width of the house to support the floor joists. Now at 24 feet, we are beyond the span capabilities of our table in our previous example. It would be possible to still frame the floor in the same way as above but just run the floor joists in the opposite direction (looking for a lumber size to span 13') but for our example, we are going to keep the floor joists running in the same direction.

So the house dimensions will now be 24' X 13'. Let's expand our house beyond that 17'2' span capability to 24 feet wide. The widest span in the floor joist span table in Part 2 of this tutorial module showed that floor joists can span 17'2' if they are 2 X 12s spaced 12' o.c. For now, we'll look into supporting the floor joists with a floor joist beam. The wall could be either a properly sized structural concrete or concrete block wall or a wood framed wall. This support could take the form of a structural wall. Once we go beyond the allowable spans for floor joists (as shown in the floor joist span tables), we will need some kind of support under these floor joists. Using Floor Beam Span TablesĬontinuing on from Part 2: Wood Joist Span Tables of Residential Structural Design, we were just about to make our example house wider. Or see our Design Your Own House tutorial site map. Or even go back as far as the residential structural design page which explains basic house structure. If you are just starting out, you might want to go to the joist page since we will expand on the house design example introduced there.

#Lvl support beam span table how to

This site also has information on learning how to read joist tables and a joist calculator. You'll find a beam span calculator towards the bottom of this page.

On this page we will explain how to read and design with floor beam span tables. Designing with Floor Beam Span Tables Part 3 of Residential Structural Design