Tearing Walls DOWN!

Barriers aren’t great …

… when they block the livability of livingroom spaces. But, 1980s suburban architects and builders (or 1990s builders working from 80s cookie-cutter blueprints) often didn’t think much about the liveability of the generic two-story homes they stamped out. The focus instead was on profit maximization, which meant maximizing the room count of sales listings.

For example, it’s great for liveability to have one large 14×30 multi-use (and light filled) space all open to a kitchen. It maximizes sightlines to make the space feel even larger, and maximizes options for laying out furniture and living areas far more flexibly than if the space were arbitrarily chopped up with immovable blank wall partitions.

However, this is a terrible strategy for maximizing new starter home sales value. What do you call that kind of layout in a single phrase in a 1990s sales ad? And, how does adding even a few extra structural beams affect the bottom line when developing several hundred homes all at once?

So instead, it made a lot more fiscal sense for builders to chop up potential great room spaces into smaller rooms that could simultaneously add advertising value and cut construction costs. Got a potential great 400-ft2 “great room” space on the first floor? Great! Cut that up into two rooms with a load-bearing wall and advertise the house as including a bonus “formal dining room” along with the requisite livingroom with the same total square footage. And, save a few grand on structural carpentry building costs to boot.

The Problem

Pretty much just described it — starter home builders generally don’t care about the actual livability of their buildings. But home buyers definitely do. That’s why the new owners of this home were determined to get rid of this especially annoying divider:

The original architect/builder had attempted to give a suggestion of openness by making a faux-arched cutout in the wall between the livingroom and “dining room” areas. The actual result was interior architecture that would be instantly dated once the Clinton administration ended.

The Challenge

The LR/DR partition wall was actually really structurally important to holding up the entire second floor of the house. That highlighted the genius of the building design cost savings. Putting a hole in a load bearing wall is easy. And, putting extra load bearing walls in homes is a real cost savings for building speed.

Making first floor load bearing walls go away? Neither easy nor cheap. But, not impossible and also not hugely expensive.

The “Theory”

Getting rid of a load bearing wall is pretty simple in theory — simply replace the wall with a post and beam strong enough to support the structural load. The main challenge is figuring out the minimum beam support necessary for supporting the maximum theoretical load that the original wall was designed to carry.

This is where past life engineering experience comes in handy. Not necessarily how you’d expect, though. It is textbook procedure to calculate the dynamic, static, shear, and other theoretical loads on a structural beam for house framing when building from scratch. But, if a builder has already done that work properly, then all a remodeler has to do is replace the existing framing with something that is at least equal. And, there are some pretty simple rules of thumb to follow for structural beams — rules that homebuilders (and architects) very likely used for being sure that the original framing wouldn’t collapse in the first place.

That’s how real-life engineering experience informs structural dynamics calculations. In the field, exact precise calculations are rarely done. Instead, rules of thumb (literally derived from the fact that the distance from the tip to the first joint of an average adult’s thumb is about one inch — handy approximation) are used to make sure that even the dopiest of construction dopes can’t screw up a framing job too badly. If you want to be fancy, then do the precise calculations to a third decimal. If you want to make sure your framing crew doesn’t screw up a job, then use a rule of thumb that any gradeschool graduate can intuitively understand.

This is why rules of thumb are also inherently conservative. It’s the Scotty Principle in action. If a beam of a given size is the absolute minimum possible, then go ahead and double that (or at least add 50%) for a good rule of thumb safety factor. Because, you never know if some unfortunately short-thumbed carpenter will be using their thumb for making approximate measurements.

The “Calculations”

So, the practical rule of thumb for a double ply white pine or similar regular common lumber beam is that it can span a length in feet equal to its depth in inches. In other words, if you’re spanning a 12-ft wide load-bearing opening then a doubled-up 2×12 white pine lumber can take the load no problem. Framing carpenters all over the world use this common lumber rule of thumb to ensure that homes don’t fall down.

If you’re wanting to minimize the size of a structural beam, though, then you’ll want to use a stronger material. LVL is a “laminated veneer lumber” material that has roughly double the load carrying strength of regular common construction stick lumber. The rule of thumb for LVL beam spans is to divide the span by 20 for the minimum beam depth. In other words, if you’re spanning a 12-ft wide load-bearing opening then a doubled-up 7-1/4″ LVL beam can take the load no problem.

That’s how remodeling calculations can be way easier than original construction engineering calculations. For a remodel, you’ve got the benefit of seeing how the framing was originally done. It makes the conversion math even easier — when substituting LVL for regular common lumber, just use a beam depth that’s at least half the original. In other words, if a house was framed with a structural opening that used a doubled-up 2×12 header then use at least a doubled-up 6-in wide LVL beam to replace it for a remodel.

The Savings

Or, for an added safety factor (and cost savings), just use a doubled 8-in LVL beam to make absolutely sure that there will never be any sagging framing issues for a wall removal where the original load was framed for a doubled white pine 2×12. LVL beams are commonly sold in just a few widths, but 16-in is a really common one that’s almost always available at any lumberyard. So, rather than buying two special order skinny beams, it’s most economical to buy a single length of beam and then simply ripsaw it down the middle.

The Process

Again, straightforward in theory. With two sets of second-floor support joists coming together at the wall to be removed, replacing it with a post and beam simply required supporting the ceiling on both sides with temporary wall framing until the new beam was erected. In total, it was a seven step process:

  1. Demo the existing wall down to the studs
  2. Build temporary exposed stud support walls on each side
  3. Demo the existing wall studs and framing
  4. (Re)move the electrical wiring
  5. Install the new post and beam
  6. Remove the temporary support walls
  7. Wrap the new post and beam in drywall, paintable mdf, or stainable pine

The least expensive finish option would be to simply wrap the new structural beam and post in finished drywall to also make it as visually unassuming as possible. The simplest finish option would be to wrap it in primed pine or MDF (medium density fiberboard) for painting. Read on to see the option that these folks chose…

The Action Pics!

But first, there was demo to do. The original house framers had actually used a beam in the original construction, so sizing the new replacement beam was a cinch:

Capping the two electrical outlets and moving the overhead light switch were also nicely straightforward tasks. The outlets were on the end of a circuit run, so there wasn’t even a need to leave a splice box in the new framing post. And, using five 2x4s to make the 5″x6″ post framing left just enough room to creatively install a new switch box.

Putting up the temp support framing was also a cinch using the pro trick of assembling the studs and footer/header flat on the ground and then hefting into place.

IMG_8807

Installing a doubled-up ~10-ft LVL beam usually takes at least two workers, but if you prefer working solo (like me) then there’s a trick for that too. Simply nail up the first 2×4 post support at one end and then heft each LVL piece into place one at a time. Just shave a 1/4″ or so notch off the corner of the beam that’ll be resting on the 2×4 support while you lift up the other end — that’ll ensure the beam doesn’t get pinched by the ceiling header while rotating into place. Then just support the other end with a tight dry-fit 2×4 while squaring everything up, add the additional 2x4s to make firm sound posts, and screw it all together.

Then just repeat the process for the second LVL beam and screw all the beam pieces together as a final step. Viola — a solo process that even Bob Villa would be proud of:

IMG_8814

The original wall framing had an extra set of ceiling headers that made the total wall width 6-in. So, to eliminate the need for a whole lot of ceiling patching (and therefore keep labor costs down), two additional 2x10s (milled to 8-1/2″ depth) sistered to the LVL beam matched the original 6-in wall width.

This added a bit of extra safety factor strength to the finished beam assemply, but mainly made it possible to extend the finish wrapping all the way to the opposite wall corner for a more finished and purposeful look.

The final semi-finished beam (with a milled-down 1×12 pine board facing already installed on one side) and 2×4 posts framing looked like this:

The Final Finish

The easiest way to put an appearance finish on a structural post and beam is to simply wrap all the framing in 1/2″ MDF cut to size. The material is cheap and this approach requires very minimal sanding since any noticeable seams can simply be filled with caulk before painting.

But these folks really wanted to highlight the new post and beam as a new visual focus for their new great room space. So, they chose to wrap the framing in finish wood that could be stained for a much more dramatic finished look.

The cabinet grade pine looked like this after three rounds of sanding to eliminate seams and get the wood prepped for a nice even stain:

Luckily the house was vacant at the time, so dust containment wasn’t too difficult.

And the end result? Vola — a new open space that’s actually more structurally sound than the original framing! The clients did the stain work themselves for even more cost savings, and the final look turned out great!

Here’s the big finish montage:

If only tearing down border walls were so easy …