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There is an old idiom that states, “The Devil is in the Details”. It refers to a catch hidden in the details. This means that something may seem simple at first but that there is more to it than expected. It seems like an appropriate phrase to describe today’s construction. As labor shortages continue to impact residential construction, as building codes grow, and as more states place higher energy performance standards on homes it just seems to be an appropriate phrase. As skilled craftsman leave the home building industry without being replaced, and as requirements for new homes continue to increase, it means many details are getting missed in a typical new homes construction. Here is a pictorial display of how the consistency of modular construction means that the details still matter.
It’s About Consistency
When it comes to doing anything, consistency matters. Just because something is specified or supposed to be done isn’t enough. There needs to be a process around it to insure that it is done every time and that it is done correctly. That type of consistency can only be delivered in a factory. When building outdoors the environment is actually working against the home builder. You just can’t expect workers to be able to perform tasks and install materials the same way on a sunny, 90 degree day as you would on a rainy, 40 degree day.
Modular is a construction method, not a type of home. The secret is the process for the modular construction method. Building indoors in a factory concentrates the construction of many homes in one location. Processes are created and followed. Inspections are done to insure the process. In field construction, when a standard can’t be consistently met, most often the standard is just eliminated as being too difficult to meet. In the factory environment, continuous improvement means that a process is improved until the standard is continuously met.
The Details are the Process
Here are just some of the details in the modular construction process followed by many factories:
Floor Construction Details – This is just an example of how a factory, with minimal effort, can increase the incremental strength of a module. Instead of a butt joint, the simple detail of lapping a corner on a floor adds strength. A modular home is typically overbuilt to withstand the rigors and stresses of being transported and then lifted with a crane. The modular process is chock full of similar details to insure that a modular home is over-built.
Protecting the Floor During Construction – In typical home construction it isn’t a subcontractors job to clean up after the previous subcontractor in the process. In flooring, after the drywall crew is done, it isn’t the carpet man’s job to clean up any lumps of spackle left on the floor. Call backs come when a homeowner complains that there are lumps in the carpet. The builder comes and pulls it back to discover piles of spackle that were never removed. In modular construction most factories apply plastic or some other cover to floors before a wall is ever set on them. At the end of the process, the covering is removed and the subfloor looks just like it did at the beginning of the process.
Sealing the Holes – In most modular factories, a home is built from the inside out. This means that because your homes modules are built indoors and protected from the elements, the hurry to get the exterior walls up and covered and to complete the roof is eliminated. What this also means is that the factory can take the time to methodically seal the holes in walls that building onsite just doesn’t allow. By sealing every wall and ceiling penetration, along with every place wire enters an outlet or switch box, air infiltration is virtually eliminated. Not only air, but bugs, rodents, etc. just can’t get into the wall cavities of a home.
Wall Connections – In typical onsite construction, walls are connected with 16p nails. If you would observe a framing crew you will hear the pop-pop-pop of a nail gun as they shoot nails in corners where walls join each other. However nails are smooth. They can pull and back out. In most factories, everywhere there is a corner or where an interior wall meets an exterior wall, the standard is to use screws or lag bolts. Screws and lag bolts don’t pull out. Not only are they used on walls, but they are typically used to connect walls to floors. Using screws and lag bolts means your home is prepared to successfully make the ride to your home site. It also means the home is better able to withstand the rigors of future storms.
Exterior Continuous Connections – Look at how modular homes perform in storms. From Hurricane Andrew in Florida to Superstorm Sandy in New Jersey and New York, modular homes typically protected their owner’s families better and weathered the storm intact. Why? A modular home has to be built strong to be transported to a home site and lifted with a crane. This may sound like a simple detail but it is one that isn’t accomplished well in on-site construction. In modular construction, the floor is attached to the wall system, and the wall system is then attached to the ceiling system. These attachments are done with straps, screws, lag bolts, and special (longer) OSB. In onsite construction, nails are typically all that are used. The combination of some or all of these items in modular construction means that a home is tightly bound together from top to bottom.
Blocking Means Strength – Blocking means adding extra wood behind drywall to provide strength for attaching items to a wall. This could be for kitchen cabinets, adding grab bars in bathrooms, and/or to support shelving. In modular construction, blocking is used liberally. The modular construction process works to find ways to productively reuse scrap in the home building process. Scraps of lumber and OSB are perfect to add strength to walls and to enhance the use of the home for the future.
Sealing Between Modules – There are several ways to seal between modules. In some cases, it is done onsite with spray foam to insure that module-to-module connections are tight eliminating chances for air infiltration. In some cases, factories add a gasket to help insure that modules fit snugly together.
Consistency in Window Installation – How many homes have you, a friend, or a family member had that has had at least one leaky window during storms? This is usually caused by improper window installation, a problem that plagues field construction. With factory construction, it is the consistency that makes the process. Window installation is a prime example of how simply installing a product correctly, and then doing it that way each and every time enhances the end product. If you have the opportunity to visit a modular factory, pay particular attention to how windows are installed. See how each and every one is done the same way each and every time.
The Traveler – With onsite construction, there is typically a local inspector (maybe) that comes to the site 3 -8 times to review certain points in a home’s construction to see if it is meeting building code. These inspections don’t address quality. At most factories you will see a box attached to every module that contains a set of documents. The box is a Traveler and it travels with the module from start to finish. The group of documents contains quality checklists to insure that a module is inspected throughout the process. It is inspected for both code and quality! The inspector or reviewer then has to initial taking personal responsibility for the inspection just performed. A factory is incented to make sure that issues are addressed in the factory on the production line. Any problems that reach the field are expensive to fix. Doing it right in the factory is the most cost effective way to build a home.
Modular Construction Brings Consistency to Home Building
Every custom home that is built has its challenges. While most home buyers today are focused on features and amenities of their new home, they need to at least be aware of how their new home is constructed. It is the largest investment that most people will ever make in their lifetime. The way the home is constructed and the attention to detail can mean the difference in having a home that is comfortable to live in, offers reduced power bills, and offers a lower incidence of issues and callbacks. Consistency in construction means dependability. Dependability translated means modular.
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