Span Tables for LVL Beams: A Step-by-Step Guide

When it comes to sizing an LVL (Laminated Veneer Lumber) beam, it can be a daunting task, especially when the specifications don't fit neatly into the manufacturer's generic span chart. In this article, we'll break down the process of calculating the correct size for your LVL beam.

To start, let's consider the ceiling joist configuration. In our example, we have 5/8' drywall with two layers and then attic space above with blown-in insulation. The ceiling joists are not continuous, but rather tie into an LVL beam to provide additional support. This means that we need to calculate the PSF (Pounds per Square Foot) rating for this specific scenario.

A common mistake is to assume a 20PSF rating without considering the actual span carried by the ceiling joists. In our case, the ceiling joists are 14' long, which would result in a total span of 28'. However, when calculating the PSF rating, we need to halve this span to account for the fact that the LVL beam will only be supporting half of the total span.

To calculate the correct PSF rating, you'll need to consult your manufacturer's technical sheet and follow their guidelines. In our example, let's assume a 20PSF rating based on the provided information. However, it's essential to verify this calculation with the manufacturer to ensure accuracy.

Now that we have the PSF rating, we can move on to calculating the size of the LVL beam. This is where things get a bit more complex, as we need to consider the PLF (Pound-Force Load) rating for our specific scenario. The PLF rating takes into account the weight and distribution of the ceiling joists, as well as any additional loads such as wind or seismic forces.

To determine the correct size of the LVL beam, you'll need to consult your manufacturer's span table and follow their guidelines. These tables typically provide two options for premade spans, but what if your specific situation doesn't fit neatly into one of these categories?

That's where this article comes in. By following the step-by-step guide outlined above, you can accurately calculate the correct size for your LVL beam, even when the specifications don't align with the manufacturer's generic span chart.

In conclusion, sizing an LVL beam requires careful attention to detail and a thorough understanding of the PSF and PLF ratings. By following this guide, you'll be able to confidently calculate the correct size for your LVL beam, ensuring that it provides the necessary support for your ceiling joists and meets all relevant building codes.

Span tables for lvl beams