Why You Must Air Seal Your Modular Home
I’ve written in the past why it’s important to air seal your modular home. It’s because air infiltration in the gaps where modules are joined can cause a great deal of heat loss. If you want an energy efficient modular home, you need to air seal these gaps.
The modular manufacturer can control air infiltration within each of the modules, but when the modules are placed side by side or stacked on top of each other, significant gaps are created. It is just not possible to bring two modules together tightly when a cable is wrapped around each one while being lifted onto the foundation. In addition, even when the framing of one module is tightly butted up against the framing of another module, it is not possible to make the joint airtight.
What Can Happen When You Don’t Air Seal Your Modular Home
One of my first customers, Jim, hired a general contractor who didn’t take this seriously. Jim’s home was a raised ranch with a drive under garage. It was a good sized home, 28’ x 60’.
When Jim called me, it was after three winters of substantially higher heating bills than he expected. His first comment was, “You said my home would be energy efficient. But my heating bills are almost as high as for my previous home.”
When we visited his home to complete an inspection, we expected to find that his contractors had not insulated the basement walls, as Jim and I had discussed while planning his home. We also thought his contractors might have failed to put the attic insulation back in their bays after completing the button-up work. Plumbers, heating contractors, and electricians often pull out some of the attic insulation so they can do their work. Sometimes they forget to put it back, and the general contractor forgets to make sure they do.
But that’s not what we discovered. So we performed a “smoke test” to see where air might be leaking. What we found was that the joint where the front and back modules met in the basement and in the attic had not been air sealed by Jim’s contractors. This gap at the “marriage wall” was creating a “chimney” effect, which was allowing the air to flow – and heat to escape – up through the middle of the house all winter long. Although this was seriously compromising the energy efficiency of Jim’s home, we only needed a couple of hours to seal the marriage wall.
As we agreed, Jim called me after his next heating system. He happily reported that his heating bill was substantially lower.
Have Your General Contractor Air Seal Your Modular Home
Ever since this experience, we’ve made sure to emphasize to our customers and their general contractors that they are responsible for completing the air seal where the modules join. But we still find that some GC’s fail to do this task. I strongly suggest that you ensure that your GC does.
For more information about why you must air seal your modular home, see The General Contractor’s Responsibilities for Building a Modular Home in my book The Modular Home. For information about how to properly air seal a modular home check out this blog post and my Checklist for How to Air Seal a Modular Home.
The GC’s Responsibilities for Preparing for Delivery and Set
The GC is responsible for preparing your site for the delivery and set of the modules. More specifically, he is responsible for preparing both the access leading to the lot and foundation, and the area where the crane and modules must be located during the set. If the area is flat, with good soil conditions and relatively wide, straight roads, this responsibility may be without challenges. On the other hand, problems can arise on what appears to be an easy site. Bad weather, poor soil, loose fill, a utility pole in an inconvenient place, a septic system located where the crane needs to go, a customer’s refusal to cut a favored tree or remove an old stone wall; these are the kinds of things that can turn a site into a logistical challenge, or even a logistical nightmare.
When the manufacturer’s delivery time from its factory to the site is more than a couple of hours, it will deliver the modules at least one day before the scheduled set. In such a situation, the GC should try to create sufficient space on the site to store all of the carriers overnight. Since the most efficient way to set a home on the foundation is to place the crane in front of the house with one carrier on each side of the crane, the preferred storage plan is to create a space wide enough for the carriers to be delivered directly to these positions. Unfortunately, the combination of lot size and configuration, topography, soil conditions, foundation size, and the number and size of the modules can sometimes make it impossible to place all of the modules in the right place while preserving room for the crane to set up.
Need for Staging Areas
When the modules cannot be properly placed, one or more of the carriers have to be delivered to a temporary storage location, which may be at another location on your site or at a nearby parking lot or open field. The carriers will then be moved to their proper positions next to the foundation on set day. Although the GC is responsible for preparing the site to facilitate these efforts, he is not responsible for things beyond his control, such as a heavy rainstorm that washes out the driveway. Nor should you expect him to pay for the required repair.
Risk of Delivery and Set Delays
If the GC does not prepare the site in a satisfactory manner, and this causes the delivery and set operations to be delayed, you and the GC will be liable for the additional costs incurred. The drivers and escorts that deliver the carriers will budget enough time to drive directly to the site or wherever you designate. They will expect to maneuver the carriers into place with reasonable effort, and then leave. They will not expect to spend hours waiting for trees to be cut, fill to be delivered, or a bulldozer to arrive. If any of these are required, the delivery company will charge the modular dealer, who will in turn bill you, for the additional time. The crane company will charge the dealer by the hour, with a minimum fee. The longer the set takes, the more the meter runs. The crew that completes the various set activities will also charge the dealer for any lost time caused by the delays, and the dealer will pass this additional expense on to you. If the delays were caused by the GC’s poor site preparation, it fair for you to submit the invoices from the delivery, crane, and set companies to the GC for reimbursement.
Many sets take a full day, and some take two or more days. One of the most important responsibilities of the set crew is to protect the home from weather damage as quickly as possible. If the site is not prepared, and the set is subsequently delayed by several hours, the set crew may not be able to complete enough of the set to give your home the protection it will need should it rain over night. If the delay happens before the first module is set, the set crew and modular dealer can cancel the set and reschedule it for the next available day. But if some of the modules are already set on the foundation, with the protective coverings removed, the set cannot easily be stopped and the crew may not be able to take the required steps to protect the home until the cause of the delay is removed. If this delay takes a few hours, the home will be exposed to the elements longer than it needed to be.
Create a Written Delivery and Set Plan
General contractors, excavators, and customers consistently underestimate the difficulties involved in preparing a site. Their misjudgments come at great expense and aggravation to the dealer and, ultimately, the customer. The best way to avoid a disagreement between your dealer and the GC, if they are not the same company, is to have them meet on your site before any work begins to jointly develop a plan. The dealer should put the plan in writing so that both parties have written documentation. The plan should indicate what the excavator needs to do to properly prepare the site as well as where the dealer intends to place the carriers and crane. If a problem develops on the delivery or set because the plan was poorly conceived, although executed correctly by the GC, the dealer will be responsible for any additional costs. When the excavator is about halfway done with his preset work, the dealer should again meet with the GC to review and, if necessary, update the plan; the best thought-out excavation plans do not always work as well on land as they do on paper. If the dealer has any lingering concerns, he should return for a third visit just before the excavator is ready to leave the site. Either way, the dealer should visit the site for a final pre-set inspection after the GC reports it is prepared.
For more information about the delivery and set of a modular home, see Finding and Preparing a Building Lot for a Modular Home, Selecting a Modular Home Dealer, and The General Contractor’s Responsibilities for Building a Modular Home in my book The Modular Home.
Responsibility for hiring the modular home set crew and crane should always be left to the modular dealer or manufacturer. A customer should refuse to hire the modular home set crew and crane, even if a dealer promises it will save substantial money.
Why You Should Never Hire the Modular Home Set Crew or Crane
The set procedures require a great deal of specialized knowledge, skill, and teamwork that a modular set crew acquires only through training, supervision, and experience.
Because of the size and cost of the modular units, as well as the risks associated with the modular home set procedure, whoever sets a home has substantial liability.
If a modular home set is done poorly, the general contractor’s job will be made substantially more difficult and the quality of the finished home may suffer as a result.
If someone on the modular home set crew is injured, the person or company that hired the crew could be held liable.
Why Would a Dealer Want You to Hire the Modular Home Set Crew and Crane
The goal of a dealer who asks the customer to hire the crane and the modular home set crew is to hold the customer responsible for any problems with how the house goes together. Since he neither built nor set the home, the dealer can disclaim responsibility for any problems. It is best to avoid dealers who operate this way.
For more information about hiring a modular home set crew, see Selecting a Modular Home Dealer and The General Contractor’s Responsibilities for Building a Modular Home in my book The Modular Home
The previous two posts listed the tasks that must be completed before your modular home can be delivered and set on its foundation. This post will discuss how long it takes to complete all of these preconstruction tasks.
How Preconstruction Tasks Affect Your Move-In Date
Most people building a new home are prepared for the construction to take longer than planned. They have heard that subcontractors, inclement weather, utility companies, and inspection officials all contribute to delays. Few people, however, anticipate how long it takes to complete those tasks that must be done before they begin construction. Consequently, they budget too little time for these preconstruction tasks and then try to compensate by skipping some tasks and rushing through others. When this strategy fails, they miss their desired move-in date and pay for it with stress with their family, conflict with their dealer and GC, and cost overruns with their budget.
How Long It Takes to Complete Preconstruction Tasks
It can take you as little as five weeks or as much as a year or more to complete all of the preconstruction tasks listed in the previous two blog posts. But all of them must be done before your modular home is delivered and set on its foundation. Your responsibilities can take as little as one day, if you order a standard modular plan with no changes, select only standard features, agree all decisions are final, have cash to pay for everything, have a GC lined up and ready to go, and have a building permit in hand or don’t need one. If this is true for you, you will be an exception.
More likely, you will want to customize your modular and GC drawings and specifications, require some time to consider your decisions, and need to wait for the lender to approve your loan and the building department to issue your permit. You may even want to revise your drawings and specifications two or more times. Consequently, you will likely need several weeks before you are done with your preconstruction responsibilities.
Even if you are able to make final decisions about your drawings and specifications in one week, the manufacturer cannot build your home, and you do not want the manufacturer to build your home, until you have obtained a building permit and secured financing. These preconstruction tasks can take a couple of months. Closing on a construction loan often takes six to eight weeks, completing the preliminary steps required to apply for a building permit can sometimes take several weeks, and receiving a building permit after submitting the application can take up to 30 days. One of the most important variables affecting whether you will be done on time is how quickly you begin your efforts. If you wait two weeks, you will not be able to make up the time by asking your dealer, GC, lender, or building department to work faster.
Other Preconstruction Tasks
The start of your schedule will also be extended if you have not completed all of the following preconstruction tasks before you order your home, if you need them done:
- Secured a building lot or will purchase one immediately
- Surveyed your building lot
- Resolved any deed and zoning issues with your building lot
- Resolved any wetland issues with your building lot
- Obtained a valid perc test and at least applied for a engineered septic design
- Selected a GC and/or subcontractors
Once you complete your preconstruction responsibilities, the manufacturer will need a minimum of five weeks to complete its tasks. The manufacturer typically requires at least three weeks to complete your production drawings and order your materials, one week to build your home, and one week to get it ready for shipment – for a total of five weeks from the date you are ready. It does not matter whether you complete your responsibilities in one day or one year, the typical manufacturer still needs a minimum of five weeks. Furthermore, if you select materials that need to be “special ordered” or are “back-ordered”, the manufacturer will need even more time. And if the manufacturer has strong sales, its backlog of orders can add several weeks to its schedule and your delivery date.
For a detailed schedule of when all of your preconstruction tasks must be completed as well as each player’s responsibility for completing each of these tasks, see Building a Modular Home on Schedule in my book The Modular Home.
The best way to evaluate the modular home quality provided by dealers and manufacturers is to walk through one or more of their homes. No amount of words of reassurance from a dealer will be as helpful as seeing the modular home quality with your own eyes. You may be able to view a home in one or more of the following situations:
- A home at the end of the manufacturer’s assembly line
- A home immediately after it is set
- A finished home
Since you are likely to view a home in only one or two of these situations, it is important that you know what each situation tells you so you are not misled by what you see.
Modular Home Quality at the End of the Manufacturer’s Assembly Line
Viewing a modular home at the end of an assembly line is the best way to learn about the manufacturer’s level of craftsmanship and quality control apart from the contribution of a general contractor’s finish crew. Any one house on any given week may or not be representative of what the manufacturer’s typical home looks like, however, since all modular factories have some variability in the quality they produce depending on the design of the home, which of their crews work on the modules, and whether they are behind or ahead of schedule. In addition, most manufacturers spend from one to three days fine-tuning the appearance of the modules after they come off the production line and before they are delivered to the dealer. This means you need to see a home after it has undergone this cosmetic makeover to assess the modular home quality you will receive when it is ready for delivery.
Modular Home Quality Immediately after the Set
The delivery and set of a modular home will always impose minor stresses on the structure of each module. These will inevitably produce some visible symptoms such as small drywall cracks and slight misalignments of moldings and doors. Although these symptoms are easily fixed by a competent modular general contractor, it is worth knowing what affects their frequency. Longer modules with long open spans, where the walls between modules have been removed to make a larger room, are especially vulnerable to these symptoms. This will be less true for those manufacturers who sheath the outside of the marriage wall, which joins two modules, or use some other comparable technique to strengthen the structure. Those manufacturers who temporarily brace the open spans during delivery also tend to have fewer symptoms. You will likely see more of these symptoms when a manufacturer uses old carriers with weak suspensions to deliver the modules.
Difficult delivery routes and rough site conditions will have the same effect on modular home quality you see after the set. How the set is conducted, especially how the set crew picks up each module, will also affect the number of drywall cracks and misalignments. Using more straps for longer modules will provide greater support and thus reduce the stress on the modules. Consequently, when you view the modular home quality immediately after the home is set, you will not necessarily know whether any drywall cracks and misalignments were caused by the manufacturer’s construction, one of the other factors, or a combination of the two. On the other hand, should you see a home with few drywall cracks and misalignments, you can feel reassured about the work of all of the respective players.
Modular Home Quality after Construction Is Completed
The modular home quality you will see after a home is finished is a product of both the manufacturer’s and general contractor’s efforts. Not surprisingly, some manufacturers deliver better quality than others. The same is true for GCs. A modular home will exhibit the best quality when both the manufacturer and GC are top-notch. But you might be surprised what a very good GC can do with a home manufactured with below-average quality, or how poorly a well-built home can look when buttoned up by an ineffectual GC. When you view a finished home, whether a customer’s home or a model home built for a manufacturer or modular dealer, you need to consider who served as the general contractor, and whether you will be using the same one to complete your contracting work. If you are considering using the same GC and you like the quality, you will not need to be as concerned with whether the home was delivered with this quality or it was created by the GC. On the other hand, if you do not find the modular home quality acceptable, it probably will not matter to you who was responsible, since you are likely to look elsewhere for a dealer and GC.
It gets more complicated when you like the modular home quality but are not planning to use the same GC. Your eyes will not be able to tell you whether the manufacturer built the home with good quality or the GC did a superior job improving what the manufacturer delivered. You may be able to learn more if you can talk with the customer, but this will not be possible if you are looking at a model home. If the quality is less than you expect, you will have to look closely to determine who was responsible for the unacceptable workmanship. If the entire home appears to suffer from poor workmanship, chances are good that both parties share the responsibility. If you are not hiring the same GC that worked on the home or homes you inspected, it is a good idea to visit a couple of the manufacturer’s homes at the factory or immediately after they’re set.
For more information about assessing modular home quality, see Selecting a Modular Home Dealer, Designing a Modular Home, Modular Home Specifications and Features, and Selecting a General Contractor in in my book The Modular Home.