It's Called "Advanced," So I Should Do It, Right? Learn About the Pros and Cons of Advanced Framing--BYHYU 016
One of the most important decisions that will made about the construction of your home is what type of framing it will have. And granted, it’s not one of the most exciting decisions, but it is one of the most IMPORTANT ones. How your home is framed will significantly impact your wallet, both during and after construction. The framing impacts the energy efficiency and comfort of your home and it has some impact on the environment, depending on how much material is used and wasted during construction.
My goal, of course, is not to make us experts, not to train us to go to the job site with a hammer in hand and act as framing carpenters (that’s what the framing crew is for). My goal is to give you a good overview and foundation of knowledge that will help us intelligently converse with our contractors about our construction options, in this case the option of advanced framing.
You know, I think it's such a shame that most people think more about the options on a car they are thinking about buying or a vacation they are planning on taking than they do about the options for their new house, the biggest investment they will probably ever make. So, kudos to you for educating yourself.
Before we learn about advanced framing, let’s go over some pro terms. They are all framing terms. There are a gazillion pro terms related to framing, but I’ll quickly define just a few of them today.
Our first term is wall studs. Now most of you know what a wall stud is, but for the sake of being complete, let me give the proper definition.
Wall studs are a collections of vertical framing members that are the fundamental elements of wall framing. Wall studs are often 2x4 or 2x6 pieces of lumber that are spaced apart equally and are hidden behind drywall once construction is complete.
Joists: Smaller beams, set on edge and arranged in parallel. Joists are used to support floor and ceiling elements. That’s why you’ll sometimes hear the terms floor joists or ceiling joists.
Top Plate: The top plate is the top of a stud wall. It’s that simple. And guess what the bottom plate is. It's the bottom of a stud wall.
Header: Headers are pieces of lumber installed at the of top of window and door openings. Like our heads are to top of our bodies, the header is the top of window or door openings.
So, in summary, a wall is a collection of studs (usually 2x4 or 2x6 pieces of lumber) that are equally spaced and sandwiched between top and bottom plates. Joists are arranged in horizontal rows to support floors and ceilings, and headers are at the top of window and door openings. Now, let’s talk about the pros and cons of advanced framing.
Critics of traditional framing say the process uses too much wood—more than is necessary, which not only increases your lumber bill, but also your utility bill, since wood is a bad insulator.
In traditional framing, lumber accounts for about 25% of the wall volume. Traditionally framed walls typically use 2x4 wall studs on 16 inch centers, meaning the wall studs are 16 inches apart.
As a way to help builders decrease the amount of lumber used so they could reduce costs, Advanced Framing (AF) was developed decades ago. AF was the brain child of HUD, the US Department of Housing and Urban Development. More recently, those interested in energy efficient and green building practices have adopted AF. Instead of traditional 2x4 studs on 16 inch centers, AF uses 2x6 wall studs on 24 inch centers. This not only uses less lumber, but it provides wider and deeper cavities for insulation.
So, Advanced Framing, also called optimum value engineering, increases the insulating capacity, or R-value, of walls and, to some extent, AF reduces thermal bridging. Ok, Pop Quiz: What are thermal bridges?
I first defined thermal bridges in episode 10 when Ben Adam Smith and I talked about green building and I mentioned thermal bridges again last week in episode 15. Do you remember what thermal bridges are?
Thermal bridges are bad. They’re weaknesses within the home’s structure where heat is transferred at an increased rate. Think of them as actual bridges where heat can easily cross from inside the house to outside and vice versa.
Heat moves through wood four times faster than it moves through insulation, so less wood equals less heat transfer. And less heat transfer translates into a house that is more temperature-stable and more comfortable.
Since we’re talking about thermal bridges, let’s review what a thermal break is. A thermal break is a good thing. It BREAKS the the thermal bridge so heat cannot readily cross. Good insulation provides a thermal break.
Ok, so, AF decreases the number of wood studs, which are thermal bridges. With fewer wood studs you can get more insulation into the walls, which increases the walls R value. Got it?
Other AF techniques include: 2 stud corners, also called California corners. This allows more insulation to be added to the corners of the house. Traditional framing uses 3 studs in the corners of the house. This means that corners are filled mostly with wood, creating a thermal bridge.
There is often minimal or absolutely no insulation in those traditional 3 stud corners. Changing to 2 stud corners can increase energy efficiency, but you should know that California corners can also present some challenges for hanging drywall. But these challenges can be overcome with the use of drywall clips.
TRADITIONAL 3 STUD CORNER ON THE LEFT
ADVANCED FRAMING 2 STUD CORNER ON THE RIGHT
Another feature of AF is that AF eliminates headers on non-load bearing walls. And in place of those headers, insulation is added, again increasing R value. AF also eliminates wood from the top plates, so instead of a traditional double top plates, single top plates are used.
Let’s go over some more advantages of AF:
1. AF Decreases materials and labor costs (sometimes). You typically save on the amount of lumber required for framing. Advanced framing can reduce the amount of lumber used by 14 to 20%. And if you are in an area where there are framers experienced in AF, you can save on labor since AF requires less lumber and theoretically, less time for framing. If, however, framing crews in your area don’t have much experience with AF, they may you charge more.
2. Some experts say AF Increases structural integrity of the home because it uses a stacked framing method. This AF method is called stacked framing because framing members are stacked vertically, on top of each other. So framing members create nice, straight, vertical lines, which creates a direct load path and that direct load path increases structural integrity.
3. Sustainability. Wood is a renewable resource and AF is an even more sustainable process since it reduces the amount of lumber needed for a project.
4. Fewer drywall defects is another advantage. Problems like cracking and nail pops are often eliminated. Applying sheetrock with drywall clips is required with AF and the use of drywall clips eliminates much of the cracking seen with traditional drywall installation.
Despite those benefits, many builders have been reluctant to adopt AF. Why? Well there are many reasons, but one of the main reasons is, like many of us, builders and framing carpenters don’t readily embrace change. They have a tendency to want to do things the way they have always done them.
In addition, AF requires planning and many builders and subcontractors would rather build, than plan. Listen, I get it, planning isn’t the fun part, building is, but whether you decide to use AF for your house or not, having a detailed plan for your framing, plumbing, electrical, HVAC, and every other part of your home will decrease the number of problems you have throughout the construction process.
Ok, now they we’ve covered the pros of using AF, let’s take about the cons.
Critics of AF say that the method is inferior to conventional framing because, among other things, it’s just not practical. For example, hanging cabinets and drywall, and applying window and door trim and exterior siding is more challenging because those jobs are easier with traditional framing. Just think about it, with traditional framing there is more wood to attach drywall, trim, exterior siding and cabinets. Of course all those components can all be installed in a house constructed with AF, but a few extra steps are required.
In addition to calling AF impractical, some contractors say they are not particularly impressed with the reduction in thermal bridging that AF claims to have. They say covering a traditionally framed house with continuous rigid exterior foam insulation dramatically reduces thermal bridging, much more so than an AF wall with no exterior insulation.
Some other cons of AF are:
It’s typically more challenging to find framing crews with AF experience, as I alluded to earlier. And if experienced AF crews are short in supply, the labor may end up costing you more than with traditional framing.
Another con is that any savings in lumber costs will be partially offset by the added costs of drywall clips, thicker sub flooring and drywall and other extras that are needed if AF is used. Let me explain why thicker drywall and sub flooring are needed.
Since AF uses studs that are 24 inches on center, instead of the traditional 16 inches on center walls, there is more empty space behind drywall—less support. Therefore, if you use the half inch drywall that is typically used with traditional framing, you might get wavy or bowed walls. Switching to 5/8 inch drywall is recommended with AF. This is a stiffer, stronger product and it is unlikely to bow (the bonus here is that that thicker drywall is also quieter).
Just as you risk having wavy walls if you combine conventional, thinner drywall with AF, you risk having bouncy FLOORS with AF if you don’t choose thicker sub flooring. So AF saves on lumber, but some of those savings are lost because it must be spent on more expensive drywall, sub flooring and other extras needed with AF.
Another reason some contractors are reluctant to use AF methods is because they think single top plates are not as durable as traditional double-top-plates. They say the traditional approach is worth the extra wood, especially in areas of the country exposed to high winds, hurricanes, tornadoes, or earthquakes. Using single top plates is one of the techniques that your local building code may not allow. This brings us to another disadvantage of AF.
Local building inspectors may question and possibly not approve all AF techniques, so be sure to consult with building officials about your AF plans. Be especially cautious if you live in an area prone to earthquakes or high winds.
So that’s a lot to think about. Here’s a quick summary of the differences between traditional and advanced framing.
Traditional framing, which is the current industry standard, uses 2x4 wall studs that are 16-inches on center with double top plates, three stud corners, plus more framing around window and door openings.
AF uses 2x6 framing at 24-inch centers with single top plates, two stud corners, and less timber around window and door openings.
There are definite advantages and disadvantages to both traditional and advanced framing. Whenever I have trouble deciding on two or more options, I try to come up with what I call a hybrid solution— a solution that takes the best elements from each option and combines them into a solution that works best for me.
I think we can do that with traditional and advanced framing. We can adopt some, but not necessarily ALL AF techniques. Incorporate the AF steps that make the most sense for your project.
Maybe you are most concerned with the thermal bridges in the corners of a traditionally framed home. So you might want to adopt two-stud corners, but retain traditional 16-inch-on-center stud spacing because it is more practical for installing cabinets and siding.
Or maybe you like the idea of MOST of the AF techniques, but you’re uncomfortable with single top plates. So, request most of the AF methods, but with double top plates. Listen, I’m just assuming those hybrid solutions are possible, but since I’m no expert, talk to your builder or framer about what PRACTICAL AF methods you can add, if you don’t want to go all the way.
If you feel strongly that you want to do AF for your house and you’ve hired a builder who uses a framing crew that does not have experience with AF, both you and your builder can shop around get bids from, and references for, framing carpenters that do have AF experience.
It’s probably not a good idea to have an inexperienced crew try their hand at AF on YOUR new home. Go with a framers with experience. If you can’t find an experienced framing crew, you might consider letting go of your AF dream and going with traditional framing and exterior rigid foam insulation.
Alright, let’s see how much you’ve learned today. Ready for your quiz?
1. True or False: Wood wall studs are good thermal breaks.
False. Insulation is a good thermal break. Thermal breaks can BREAK the thermal bridges that result from wall studs. Wall studs allow increased and unwanted transfer of heat. Thermal breaks decrease that unwanted transfer.
2. What is the name of the framing member that is made up of small beams arranged in parallel rows from wall to wall to support floors or ceilings.
The answer is C, Joist.
3. Why is whole wall R value typically greater with AF as compared to traditional framing?
Because AF uses 2x6 wall studs 24 inches on center and less lumber overall, making more room for insulation.
Well, that's all I have for now. Please remember that the purpose of this podcast is simply to educate and inform. It is not a substitute for professional advice. The information that you hear is based the only on the opinions, research and experiences of my guests and myself. That information might be incomplete and it’s subject to change, so it may not apply to your project. Always consult a professional about specific recommendations for your home.
Thanks for learning with me today. Come on back next week.