House Painters Beware!
In the world of Sustainable Design and Construction, the goal is minimal impact to the environment, conservation of materials and the use of durable products that will stand the test of time. Taking this to the practical environment where costs and efficiencies are of the utmost, Designers and Builders must find those products that meet all the criteria because, in general, Home Owners that are renovating or Clients that are designing/building homes will not pay more than 3% more for “green” products. One way to achieve this and deliver a product that is low maintenance for the End-User is by using “pre-finished” materials.
Pre-finished materials are those that arrive ready to install with no additional work in the field required. This can save the Builder time and, because no field finishing labor is required, the Client money. The environmental upside is achieved as most pre-finished materials, if specified correctly, are much better for the environment because they are finished in a factory and constructed of environmentally preferable ingredients. In this installment of our on-going series about the NAHB’s Model Green Home Building Guidelines, we will look into the types of products that can come to the site beautiful, healthy and sustainable.
Exposed to the sun, rain, wind, and, now popular here on the Coast in Delaware, snow, the exterior of a home must be durable. The elements (plug intended) that can be either finished on-site or prefinished can help this durability. The exterior products available that are pre-finished are mainly a form of fiber cement. There are several great manufacturers – James Hardie, Nichiha, and CertainTeed to name a few – and all provide great exterior cladding. The look is timeless and can match the vernacular of most regions. From Craftsman detailing, to Colonial, to Modern, fiber cement siding can create the aesthetic. Additionally, fiber cement is made from water, sand, wood fibers (usually post-industrial waste) and cement. Those are four of the most readily available materials on the planet. Most fiber cement manufacturers now make their products impregnated with color. This means no painting – and no maintenance for a LONG time – up to 50 years on some products. The impregnated color is important because that means the color is a through color – if it gets nicked – sorry – WHEN it gets nicked the color is still there.
The trim around windows and doors, as well as, soffits, corners, and fascia pieces all can be found pre-finished. Manufactures like James Hardie, MiraTEC, and AZEK come ready to install. These, too, have 30 to 50 year warranties and are obtainable in smooth and wood grain. Detailing with these products puts the finishing touches on the home. One word of advice, found out the way all wisdom is gained – the hard way, check the thickness of the product you are trimming and the thickness of the trim. Some products are ¾” or thicker, so trim pieces will need to be 1” or great to make the reveal authentic instead of the ever so popular movie set fake look.
To a great extent, the cladding of the home is typically the only field finished product. These days, most windows, doors and garage doors come pre-finished. Decks are typically all floored with synthetic materials made in a wide variety of widths, colors, and finishes. Remember the great part about pre-finished is that it typically will not have to be finished again – if you are like us, that takes a potential weekend killer off the old “to do” list. The environmental benefit comes in the form of durability, as it doesn’t have to be replaced as often, and factory finishing in a controlled environment with preferable products. Next week we will move inside to pre-finished interior finishes – wood floors, plaster walls, doors, cabinets and counters….but if you think of any questions before then, contact us, we would love to help.
Economy, Efficiency, Ease and the Environment.
The methodologies of residential construction have not changed in the last 50 years. A typical single family home – whether new construction, an addition, or a remodel – starts with a bunch of wood being dropped off to the site. Sure, there have been plans drawn, a Permit has been granted, and there has been some amount of take-off done, but a truck pulls up, drops off dimensional lumber and the framers have a go at it. The construction industry is starting to change – in this week’s installment (the seventh in a series) addresses the next portion of the NAHB’s Model Green Guidelines – but also is worthwhile information whether you use this program or not.
The change lies in how walls are built. Most people, especially builders, understand the efficiency and economy of using factory built trusses and factory built floor systems for construction. Not only does the builder save time and potentially money, the trusses are stronger and more efficient than conventional framing. All of these concepts can also be applied to walls – panelized wall systems.
Beginning with the ideas of panelized wall construction, there are several varieties. Most truss companies are now set up in order to provide wall panels in the same way that floor systems and roof systems are delivered. Using the electronic plans from the Architect/Designer and Builder, the truss company designs segments of the wall that will work for shipping to the site, produces a plan for the factory to fabricate and then, in a controlled environment, the wall sections are built. These wall sections are built with rough openings for windows and doors and are labeled ready to assemble in the field. When delivered, the Builder will have a framing crew that can put the walls together with ease. The end result is less waste and quick assembly with straighter walls that have a higher quality control aspect to them. The environmental win lies in less waste because of the factory control and less possibility of trapping wet/damp lumber in a wall that is going to be covered up.
That is a conventional framing system. But there are new ideas that are gaining ground in the world of panelization (yes, an alternate world…). One of the most popular on the sustainable side of the table is Structural Insulated Panels (SIP’s). This technology utilizes panels made from a thick layer of foam (polystyrene or polyurethane) sandwiched between two layers of Oriented Strand Board (OSB), plywood or fiber-cement. The benefit is increased insulation and more importantly a huge savings of dimensional lumber – there are not studs in the traditional sense – the wall itself is the structure. The additional benefit is that you don’t have to find a stud to hang a picture – the whole wall will support art, shelves and more. OSB itself is a product made from “scraps” of wood from various types of trees and they use most of the pieces of the tree. The resins must be kept in check so as not to use formaldehyde but even when used it is well under the amount allowed by the EPA. The next step in sustainability up from these SIP’s is to use Agricultural by-products instead of polystyrene or polyurethane. The use of Compressed Agricultural Fiber panels substitutes wheat and rice by-products treated with Borates to form a dense insulated panel that has a natural pesticide built into it. This type of thinking accomplishes two sustainable goals. It uses waste from two industries – lumber production and agriculture. The second goal that is accomplished is keeping the production and products close to the site. This is an industry that could be placed in almost any area – certainly the Delmarva Peninsula with its prolific Pine plantations and Agri-business, we are uniquely suited to embrace and expand this industry.
The future of environmentally sustainable and healthy construction lies in the use of materials and like-minded technologies discussed above. We feel that this is not just applicable to those that are “green” focused – it makes sense – common and dollar sense. By focusing on these efficiencies, the product is produced faster and more economically, the field labor does not have to be as skilled and the build is tighter with less supervision required. The end result of this paradigm shift allows local businesses to expand or be created to meet these needs and the overall win for the triple bottom line are local jobs and with local jobs and local businesses more of the money stays within the local economy. Creating community, jobs, and a better product is attainable – and sustainable.
Two, Four, Sixteen, Forty-Eight….
Who do we appreciate? From a Sustainable/Green Building perspective: the person that figures out how best to lay out the home and the framing package in order to minimize waste and maximize the use of materials. In this installment (number six), we look deeper into what it means to design a home and it’s window and door locations to reduce waste and redundant framing. This may sound complicated but it’s really a game of logic and math.
In the 1960’s several modules were commonly used. Building materials were standardized and many Builders were able to do detailed take-offs in order to buy just the right amount of materials. As time went by this practice seemingly stopped and, in fact, it was barely covered in Architecture School back in the late 1990’s. Many reasons abound as to the why of this practice going by the wayside. Chief among them are the fact that material costs were low and labor was high – it was easier to buy too much material and to not have to pay attention to module design in residential.
Watching your dimensions during the design phase is essential. If you are working with an existing plan, take a look at the dimensions based on the tips below and see if the home can be tweaked in order to accomplish less waste. The way that we look at it, if there are a few feet of wasted plywood lying around the jobsite, you just lost square footage you could have had or paid for square footage now in a dumpster.
The first principle has to do with dimensions parallel and perpendicular to the main joist span. Obviously, right? Kidding. The joists in the first floor and second floor of the home (for most homes) will span the same way between bearing points. Perpendicular to these joists, dimensions should be able to be divisible by two. Parallel to these joists the dimensions should be divisible by four. The two foot dimension allows typical spacing to work best and will not have a “wasted” cavity. In the perpendicular direction, the four foot dimension allows full sheets of sheathing to be used without waste.
The second principle has to do with placement of doors and windows. One side of the opening should be aligned with a stud – be that 16”, 19.2” or 24” – in its normal spacing. This will save a stud by not having to use a mid-span stud for the bracing/support of the opening. If you are really good – both sides of the opening will fall within the typical stud spacing. This is done by using modular window/door sizes that are dimensionally appropriate. This should be done where possible – with the need for egress windows (windows in sleeping areas allowing an occupant to get out in an emergency) and accessible doors (doors for disabled persons – which are also necessary for things like refrigerators, washers, dryers and that HUGE couch you just had to have….) – it is not always possible but keeping it in mind will optimize the layout.
The best way to accomplish this and reduce waste elsewhere is to create a framing plan and a detailed take-off list. A detailed framing plan will illustrate where each framing member will be located and the take-off list will produce the “shopping list” that is needed by the Builder to purchase just enough materials. These can be time consuming but we think money well spent. It reduces cost by only purchasing the materials that you are going to use – no reason to donate lumber to your Builder’s next job, right? It reduces waste by using whole sheets of plywood and other dimensional members. These two pieces of information along with an onsite cut list will insure this is time well spent. An on-site cut list is basically the “recipe” to the “shopping list” that is the take-off. This cut list shows the framer where each piece of sheathing is to be placed and where the studs will line up. The first time a framer sees this you will hear words or combinations of words that you may have never heard before. The purpose is not condescension or to show how big a brain your designer/truss engineer has – the purpose is to alleviate waste by figuring difficult areas in 2-D not IRL (sorry, just learned that and had to use it. IRL=In Real Life).
The tough part of these two principles comes into effect because bath tubs and hallways are not based on these two and four modules but, hey, the whole reason designers and architects exist is to make good decisions on layout and optimize conformance. And you thought it was only to take your money and annoy your Builder. We are here for that but it is secondary to laying out a perfect living space for Clients. Remember, each decision that we make that is beneficial for the environment, whether big or small, is a positive. If you have any questions or comments about this or any other sustainable ideas, let us know we are here to help.
Wood Butchers Beware
“Wood Butcher” is a colloquial name for Builders in general but more properly Framing Contractors. Poll Framers on whether it is better to have more wood or less in a home and you will get an almost unanimous “more is better.” In a home that has been properly designed by a Structural Engineer and coordinated with an Architect/Designer and the Builder, this is not always true. Harkening back to my college days and quoting a famous Architect – sometimes “less is more.”
Mies van der Rohe aside, there is something to advanced framing techniques that make this subject a portion of the NAHB’s Model Green Home Building Guidelines. This week, our fifth installment, addresses the techniques, principles and benefits of utilizing certain framing concepts.
In the Guidelines, the team must incorporate a few of the following performance requirements:
- 19.2-inch or 24-inch on-center framing/floor systems
- 19.2-inch or 24-inch on-center framing/bearing walls
- 24-inch on-center framing, roof systems
- 24-inch on-center interior partitions
- Single top plate walls, in exterior and bearing walls
- Single top plate walls, in interior non-loadbearing walls
- Right-sized headers or insulated (box) header (where required)
- Eliminate headers in non-load bearing walls
- Doubling the rim joist in lieu of header
- Ladder blocking at interior-wall-to-exterior-wall intersections
- Two-stud corner framing
Yes, the 19.2-inches – interesting, right? The 19.2-inch is based on using less wood in a framing wall than the traditional 16-inch on center framing. 19.2-inch spacing is one-fifth of a sheet of plywood. Works out great from a stud savings, it does make things a little interesting for the framer because there isn’t a .2 mark on most tape measures.
The point of the first four items on the above list is saving in the amount of wood in the “frame” of the home and increased R-Value because less wood, more insulation. With proper load analysis, the Architect/Designer and an Engineer (independent Structural Engineer or, even better, a Structural Engineer within the Truss Company being used to supply the roof/floor trusses). Generally, the thought is in typical framing conditions (not hurricane loading or seismic design), our stud walls are over built. The savings on this can be as much as 30% reduction of framing lumber. That’s significant.
A single top plate on interior and exterior walls is possible when the spacing of the roof and stud walls have the same spacing. A top plate transfers the load path from the roof to the walls in a bearing wall situation. The use of two top plates is when the wall and roof members do not line up – it provides a stiffer path for the load. It is best to employ this methodology only where all the top plates are single. There could be confusion otherwise as two different stud lengths would be used. The savings here is simply in wood and a tiny bit of increased R-value.
The next two ideas involve headers. Headers are the horizontal members above doors, windows and openings. Most of the time, for simplicity and accuracy, a Builder uses the same header regardless of interior, exterior, two-foot opening or six-foot opening. The sizing of these headers or, in some instances, the elimination of these headers can reduce the amount of wood – but more importantly, increase the R-value in an exterior wall. Here is another example of throwing the Bowtie (Architect/Designer), Blue Jeans (Builder) and, our new friend, Pocket Protector (Engineer) into a room to make sure the plans are clear which opening gets what as a header and to determine whether a header (on interior only) can be eliminated. It may seem like a lot of upfront work, but this exchange of information insures everyone is on the same page and is a team.
Two-stud corners (also called California corners) are a great way to increase the R-value (insulation) of a home. Typically, three studs are used for a corner, two for structure and one as a nailer for the drywall. If one of the studs is laid sideways, a portion of it can be used for a nailer and the remaining cavity can be filled with insulation. If it is more desirable, drywall clips can be used and you will still have a cavity for insulation.
Whew – this got a bit technical and a bit more involved in the actual construction process than normal. The idea here is not for you to grab a hammer and your local building supply company’s credit card and start nailing two boards together. The idea is strictly informative so that you are prepared to discuss these topics from the start – these are crucial concepts when talking to Architects/Designers and Builders. The benefits are very straight forward: reduced first cost (up to 5% of framing material cost), improved energy efficiency (up to 5% per year), and less wood consumption and less wood waste. This is not the end all – taking 5% off the cost of framing or 5% increase efficiency may not seem like a lot – and taken alone – it isn’t. The idea behind sustainable design and building is optimization of each component and summing them to optimize the entire home.
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