Throughout 2017, Dunn Solutions will keep up with Daniel Westbrook as he restores this historic Seattle residence. This video and post are part of the ongoing series. For other related posts, click here.
Removing existing bearing walls requires the installation of posts and beams to carry the load. As a remodel contractor used to working in tight spaces, I’ve found that LVL beams are a fantastic solution in these scenarios.
So, what are LVL beams? They are a dense, high-strength laminated veneer lumber made of wood and glue, which are available in many different sizes. LVL beams are available in smaller sizes that can be easily hauled to a location by hand, and screwed together to form a larger member that will meet requirements to carry a load. LVL is available in a wide variety of sizes; see this PDF for more information. The logistical benefits of LVL beams become clear when considering alternatives like glulams or steel beams, which are heavy and cumbersome. Take a look at our video about saving a cove to get an idea of how LVL beams can be used.
Now that we have an understanding of LVL beams, let’s think about the workspace. Planning for a proper installation is critical because the existing structure needs to be supported temporarily, before removing the existing wall that provides support. I like to consider how much structure the temporary walls will be supporting, as well as where they will be transferring the load below. Sometimes this will require the services of a structural engineer. In any case, be sure you know what you’re doing. I also take into consideration how much working space we will have between the temporary support walls, and then measure, cut, and locate the LVL beams between them. I do this before the temporary support walls are built (otherwise I wouldn’t be able to get the LVL beams in place).
By this point, I have already prepped the walls, prepped for bearing posts, and planned ahead as to how we will install each LVL beam temporarily before installing the support posts. Installing temporary support walls at this point is exactly like framing a wall. I like to locate each stud under a joist if possible, and use a double plate for added strength. For this project, we also installed support walls in the basement floor below, transferring any load to the solid concrete underneath. Once the temporary support walls are installed, the existing wall framing is removed.
Installing the LVL beams and posts now can begin.
Our project is limited on space, so our support posts need to be installed after the beams are lifted into place. I have found it very useful to employ temporary support posts to hold each beam in place as they are being installed. Once the beams are located in place, we measure, cut, and install the bearing posts at each end of the beam, coaxing them into place with a sledgehammer. Now install the king studs, and secure everything together using the appropriate fasteners. One little trick I like to do is use clamps to squeeze the beams together while I’m installing the engineered screws in the appropriate, specified pattern. All that is left to do now is secure the floor joists to the beam, remove the temporary support walls, and install floor joist blocking.
LVL beams are dead straight, which was a big advantage on this project compared to glulam beams that usually have a crown. The glulam crown wouldn’t typically be a problem, except that it could have put undue pressure on the middle of our second floor wall above, due to the installation below. We opted to use a 1 ¾” thick by 11 7/8” tall member of an LVL beam, and secured four of them together using engineered screws.
Not all space reconfigurations require structural beams, but in this case a structural support made with LVL beams was the most efficient choice. Here is a list of things to remember when installing LVL beams in circumstances similar to this project:
1. Some engineering may be required
Identify if LVL beams will be an advantage for the job at hand.
Get an engineer whenever you’re working with any structural modifications. Be sure to have them calculate and specify material sizes and types needed, with an engineer’s stamp on a print.
Follow the engineer’s specifications! If you don’t like the specs—offer an alternative, and the engineer can recalculate to see if it works.
2. Plan ahead
If space is limited, make sure the LVL beams are in location before framing support walls so they are not boxed out.
Identify and install temporary support walls so the structure will stay solid while work continues.
Make sure you have all materials and tools needed for the install.
3. Install the individual LVL beams and remove temporary support walls
Prep the walls to receive the beams.
Lift each beam in place, and temporarily support them with a post.
Measure, cut, and install the support posts.
Secure the beams together using engineered screws.
Install king studs, and remove the support walls.
Clean up anything left unfinished.
LVL beams do have structural limitations, so they may not always be the right choice. For our project, it was worth having the engineer run some calculations, and in the end—the LVL beams worked very well, saving time, money, and possible collateral damage!