Encouraging Feedback From Manufacturers

Have you ever had to tell a friend that their fly was down? Or maybe they had some broccoli stuck between their teeth? While it may be a little awkward to point out someone’s simple mistake, you know that ultimately your friend appreciated your honesty and candor. This leads me to ask installers “does the home manufacturer ever point out any mistakes or issues that you may have gotten wrong during the installation process?”. Since the installations of all new homes must be in accordance with their installation instructions, it seems to me that the manufacturer is in the best position to point out when something is overlooked or simply done incorrectly, even if that discussion may be a little awkward.

However, I continue to see too many cases where installation mistakes are routinely ignored by the home manufacturer. As a result, little problems become big problems which are far more difficult and costly to correct, and in some cases, correction is impossible.

For example: there are countless communities across the country where manufactured homes have had garages attached to the home. While an attached garage is a great feature to offer the consumer, few manufactured homes are designed to accommodate this add-on. Multiple structural and life-safety concerns can result from a garage attachment if not a part of the original design. Problems such as: improper fire separation between the garage and the living area (including windows opening into the garage space), overloading the roof, walls and foundation of the manufactured home due to the weight of the garage and potential snow on the garage roof, failure to provide an electrical branch circuit to provide power to the garage, failure to provide a carbon monoxide alarm as required by most state building codes for homes with attached garages, and possibly having egress doors leading into the garage space, to name a few.

Example of a “garage ready” home. Designed specifically to accept the on-site constructed garage.

When called upon to investigate problems in communities like this, I often wonder why the manufacturer(s) of these homes never mentioned that the homes weren’t designed for attached garages. Wouldn’t you think a good friend or partner would point that out and maybe suggest that they could design and construct homes specifically for garage attachments? But instead, too often not a word is said until the situation gets out of control.

In all fairness, there are now several manufacturers offering garage ready homes, but this is a fairly recent development.

I am sure you all have seen similar issues. Maybe you have seen manufactured homes in communities that have carports or patio covers attached directly to, and being supported by the home. Or maybe the homes have recessed porches or decks which allow rain water to flow between the decking boards and directly into the homes’ crawl space. Or maybe the homes are set in pits which collect water, instead of atop a slightly elevated site that will shed water away. I could go on, but I think you get the point.

Rain water falling onto this recessed porch has no where to go except into the crawl space. If enclosed by skirting, it must be fully vented and allow for the free flow of water from under the porch area.

I would hope that any business partner of mine would be just like that friend who lets me know when I am wearing my shirt inside out. But in the manufactured housing industry, that is not always the case.

A “pit set” and recessed porch. How will water ever escape this crawl space?

So, just who is in the best position to tell you when you missed a button, belt loop or maybe a tie-down strap? First off, I think the factory sales representative could be one of the first ones to let you know that there could be a problem. Next would be the factory’s service department. Anyone from the factory that visits your sites should be able to provide some feedback to improve the overall installation.

Too many factory representatives choose to overlook these issues or maybe they don’t know anything is wrong. I have long advocated for the training of service personnel, and with a few exceptions, they operate outside of the building code or regulations or even the manufacturer’s quality control process. While I have met quite a few really sharp sales people, many are a little weak when it comes to understanding code requirements.

So maybe it is time to start expecting more from our friends at the factory. It is not always easy to tell someone they are messing up, but that is what a good friend would do.

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Manufactured Homes & Attached Structures Part 1

It is pretty hard to drive through any manufactured home community and find a home that doesn’t have some type of attached patio cover, carport, deck, Florida room or door canopy. In fact, it is so common that it is almost expected by homeowners and routinely overlooked by installers, retailers, community owners and building code officials. I think we should talk about this common practice to be certain we are doing the right thing.

Typical patio cover improperly attached, adds over 1 ton of weight to the manufactured home.

 

A typical manufactured home installation manuals will say something like this:

Install site-built structures such as steps, landings, garages, awnings, carports, breezeways, porches, decks, railings, sheds and utility rooms to the manufacturer’s instructions and according to the following:

  • Construct site-built structures to be structurally independent unless provided for in the design of the home

 (there are additional bullet points in the home installation instructions that we will explore in future posts).

A properly supported door canopy!

 

So why must these common awnings, landings, steps and the like, have to be “structurally independent” of the manufactured home?

It all starts with the Manufactured Home Construction & Safety Standards (HUD Code) and the Model Installation Standards. The HUD Code is no different from other building codes as they all establish the minimum building code requirements.  Building codes cannot anticipate aftermarket construction or additions, and neither can the home producers. So, when we are thinking about attaching patio covers or carports to a manufactured home, we need to focus on the potential impact these added structures can have on the home and the foundation.

Unauthorized site-built additions to a home can impose unintended vertical and horizontal loads beyond what the building code minimum requires. Let‘s start with a look at the vertical load, and save the horizontal (wind) load for the next post.

Most manufactured homes are designed to handle a roof snow load of 20 to 40 pounds per square foot (psf) based on where the home is to be installed. In addition to this snow load, manufacturers must include the actual weight of the home itself (somewhere around 20-25 psf) and the assumed weight of the contents inside of the home (for furnishing, people, pets, etc.). The HUD Code requires that the manufacturers calculate this as an additional 40 psf. Ultimately, a typical manufactured home must be designed to support between 80 and 105 psf with limited deflection of the structure. The foundations are then designed to transfer all of this weight into the ground to assure a stable, plumb and level home.

This improperly supported deck can easily pull free from the home and collapse!

 

Now let’s assume you attach a 20’ x 12’ (240 sq. ft.) patio cover to fascia board of the home.  For a home located in the south roof load zone, that would add 4,800 lbs. (240 sq. ft x 20 psf of snow) of potential snow load beyond what was intended by the manufacturer of the home (not to mention the weight of the patio cover!). About half of that load would be transferred to the columns supporting the front of the patio cover, but the remaining weight (2,400 lbs.) is being transferred back to the fascia board, into the roof trusses and into the structure and foundation of the manufactured home itself.

You have just added over a ton of weight to the home that was not accounted for by the building code or the design of the home.

Carport pulled fascia from the roof trusses

 

I have seen first hand where this added weight has led to ceiling cracks, inoperative windows and doors, floors bowing, and piers cracking, breaking or sinking into the ground and other structural failures.

Broken ceiling panel, due to added structure.

 

There are some other issues to consider as well. The fascia board is not intended to resist the pull of an awning or patio cover. Fascia boards can easily pull free from the home and cause significant damage to the home. The same can be said for decks attached to the floor rim (or band) joist. You run the risk of deck collapse since the rim joist attachment to the floor joists in a manufactured home is not designed for attachment of a deck. The International Residential Code does not allow deck attachment to rim or band joists without a positive attachment such as a deck tension ties. Basically, a threaded rod and bracket that runs through the rim joist and screws to the floor joists.

Simpson Strong-tie deck bracket

See https://www.windsorlocksct.org/site/deck_lat_load.pdf for more details.

So that leaves the installer with two options:

  1. Install columns on both sides of an added structure so the home is not bearing any additional weight.
  2. Ask the home manufacturer to design the home to accept whatever loads will be added. In fact, a few manufacturers already have some designs, but typically they call for attachment to the side wall, not the fascia board.

Ok…we are just starting to explore this issue and there is much more to discuss!  Let’s talk about how added structures impact horizontal (wind) loads in our next post.