Installation Electrical Testing Part 2-Polarity & Operational Testing

In our last post we talked about electrical continuity testing that is required in the manufactured home installation instructions. Let’s finish the discussion on installers responsibilities for electrical testing and talk about the polarity and operational tests.

Typical electrical testing requirements

First the polarity test. In general, this is a visual “check” to assure that you have properly wired items like exterior lights, ceiling fans, and hanging chandeliers. Most of these installations are pretty straightforward; black to black conductors, white to white conductors, bare ground wire to the other bare wires. But some fixtures, like hanging lights or chandeliers don’t use color coded wires. You need to know how to identify different conductors so that you connect it to the proper conductor in the junction box.

Look closely for the ribs running along the length of the cord.

If you look closely at the power supply cord to a lamp or chandelier, you will find there are ribs that run the length of one side of the cord. The conductor that has the ribs is called the “identified conductor” and should be attached to the white (neutral) conductor in the junction box.

This may be easier to see the position of the ribbing

Now, if you don’t think this is a big deal, think again. A light fixture wired with reverse polarity can present a shock hazard. The entire socket that the bulb screws into will be energized and can shock someone should they accidently touch the lightbulb base while changing bulbs or just cleaning the light fixture.

While the instructions only require a visual polarity “check”, to be certain that you have the proper polarity, it is a good idea to check the fixture with an electrical voltage meter.  Remember, the socket should not be hot (or energized)!

 Now to the Operational Tests. In simple terms, we need to assure that all the electrical equipment in the home is properly energized and can work as intended. I highly recommend that every installer have a receptacle tester like this one from Grainger. It will check for polarity, short circuits, and test the Ground Fault Circuit Interrupters (GFCI) all at the same time.

In addition to the tester, you will need light bulbs to fit every size fixture in the home. A helper to perform this test is also a good idea!


Make sure power is supplied to the home and the circuit breakers are on. Start at one end of the home and test both top and bottom of each duplex receptacle. If any receptacles are switched, make sure the switch works.  Install light bulbs and check any ceiling light fixtures, exterior lights, chandelier, etc. by operating the switches. 

In order to check GFCI’s in the home, you need to know where ground fault protection is needed.

1.       Receptacles in bathrooms even if part of a light fixture or cabinet

2.       Receptacles serving kitchen counters, including island bars. GFCI protection is not required for receptacles in dedicated spaces like refrigerator, dishwasher, disposals, etc.  See the requirement at 24 CFR 3280.806(b).

3.       Receptacles serving counters within 6’ of a wet bar sink or similar.

4.       Outdoor receptacles.

5.       The heat tape receptacle.

There can be several slave receptacles like the one seen on the left.

Keep in mind, ground fault protection can be provided from a circuit breaker in the panel box or a single GFCI receptacle which can provide protection for other receptacles, located downstream,  on the same circuit.  For example, one GFCI receptacle in the kitchen might be attached to several other receptacles along the counter. Or the one GFCI device might protect multiple bathrooms.

So, make sure any tester you purchase comes with a GFCI test button. That way you can test the receptacles and the reset button after you trip the device.

Turn on and off the bathroom and kitchen exhaust fans. Some homes have whole house ventilation fans in the laundry area. Check them too!

Next you want to test all the smoke alarms. This test is not as simple as you may think. First you need to remove all the backup batteries from each smoke alarm. Push the test button on every alarm to check 3 separate functions:

1.       Does the alarm sound when the test button is pushed?

2.       Does the alarm send a signal to sound other alarms in the home?

3.       Does the alarm sound when it receives a signal from other alarms in the home?

Typical smoke alarm testing procedures

When you are done testing each smoke alarm, make sure to replace the batteries!

The Model Manufactured Home Installation Standards (24 CFR 3285.702(f)) do not require you test water heaters, electric ranges, electric furnaces, dish washers, clothes washers or dryers, and portable appliances. But a few manufacturers require that you check to make sure electrical power is provided to this equipment or to the receptacles provided for their future installation. So, as always, check the manufacturers installation instructions that came with the home.

 If the tests are successful, document it on your Installation Checklist and keep it in your home file. If you encountered a problem, make sure you report it to the retailer or manufacturer with a record that you reported the issue. Once the problem is corrected, you should retest the affected circuit or related area in the home.  These tests are very important and must not be overlooked. As always, check the installation instructions that came with the home!



Installation Electrical Testing-Part 1 Continuity Testing

Tucked way in the back of every manufactured home installation manual, at the end of the section titled “Prepare Appliances and Equipment” you will find the requirements for electrical testing of the home for continuity, polarity, and operation. So, I thought we should take a closer look at these three requirements so we can better understand how to conduct these important tests. Today we start with Continuity Test. 

Ultimately, you are checking to see that all metal parts in the home that could become energized, are bonded (or connected) to the grounding terminal in the electrical panel box.

 The intent of this test is to find any electrical shorts that could shock the occupant the home. 

Typical continuity tester

To conduct the test, you need a simple “continuity tester” that you can pick up at a building supply store or similar place for under $10 (I bought mine with a 20% off coupon!). Then you need a decent length (50 feet or more) of light gauge wire. I like to use 18 gauge lamp cord. An extra alligator clip might come in handy as well.

Strip about ½” from each end of the insulated wire and attach the alligator clip. Clip the other end of the wire to the alligator clip that comes on the continuity tester. Basically, you want to lengthen the little short cord that came with the tester so you can test the metal parts in a large area.

Once you have added the extra length of wire, you need to test your tester to make sure it works! Just touch the end of the added wire to the probe of the continuity tester. If you made good connections and your battery is fresh, the light in the tester should come on. That would indicate you have a “closed” circuit.

Connect the bonding wire between each chassis.

So, you are almost ready to test. First, turn off the power to the home. You don’t want to get zapped when testing the home. Next, if you are installing a multi-section home, the “Bonding Wire” connecting each chassis (or frame) must be connected.

Metal junction box needed tested for continuity

Gas line bonded to the chassis

Next, attach the end of the wire to the ground terminal (or bus bar) in the panel box. Now touch the probe to the edge of the panel box. The light should come on, indicating the panel box housing is grounded. Continue to touch the probe to any metal part of the home that may become energized while the other end of the wire is still attached to the grounding terminal.  For example, you should check the furnace housing, water heater, chassis, metal heat ducts, any gas piping, any metal siding or roofing, metal light fixtures canopies, metal bath exhaust fans, range hood, waste disposal housing, any metal junction boxes (maybe for a built-in oven or cook top).     

Now, when you are checking these metal parts, make sure you touch the probe to bare metal when possible as sometime the paint can hamper your test.

If your wire is too short and you need to move to another source to ground, you can use the ground terminal from a receptacle or attach to a ground conductor. Once you have completed the test, document it on the Installation Checklist.  

Ok, I hope this helps explain the process, I would normally tell you to refer to the manufacturers installation instructions or the Manufactured Home Construction and Safety Standards, but they lack detail. If you want to see for yourself, go to 24 CFR 3280.810 (b).  

Next time we will talk about polarity testing. 

Installer Training Course Schedule

Time to register for the last two training sessions of 2017!

For installers seeking their HUD Manufactured Home Installer License:

December 13 & 14, 2017- Okemos Michigan

For Installers seeking their Pennsylvania Manufactured Home Installer Certification (new installers or continuing education):

December 7 & 8, 2017-Lewsiberry, Pennsylvania

Email for more information or a registration form:

Four Things Every Retailer Must Know!

If you have attended any of my training courses, you’ve probably heard me say how the entire installation process starts with the retailer. Manufactured home retailers have some very important requirements under federal law that range from disclosing information to consumers, reporting information to the manufacturer and even the handling of home on display at their sales lots!

But here is the problem, far too many manufactured home retailers are either not aware of all of the things they are required to do under the federal program or just misinformed about them. Failing to carry out these tasks can derail a positive sales process and can put the retailer and homeowner in jeopardy.

This post will attempt to outline four of the most important things that retailers should know.  

Consumer Disclosure:    Before the sales contract is executed, retailers are required to provide an informational disclosure to their customers. The disclosure must be a separate document to inform to the customer that:

  • The new home must be installed to state or federal installation requirements (whichever applies)
  • Additional state or local requirements may apply
  • That the retailer can provide additional information on these requirements
  • Compliance with these requirements may involve added costs
  • If the home is relocated, it should be professionally inspected after set-up 

I think retailers should consider using this requirement as a marketing opportunity. I created this brochure (in the picture) that provides the necessary information and can be used to promote your business. This Consumer Brochure is intended to be used in states where HUD has control of installation. A few edits can make it state specific. Feel free to download and edit this with your company information, logo, change the images, etc. If you prefer a more official looking disclosure, you can use the sample form that SEBA has available on their website. Click Here. Either way, make sure you are providing a disclosure to your customers.  24 CRF 3286.7(b)

Dispute Resolution Disclosure:   At the time of signing a contract, the retailer must provide the purchaser with a notice of the Dispute Resolution Program. This notice may be in a separate document from the sales contract, or may be incorporated clearly in a separate section at the top of the sales contract. The notice must include the following language:

“The U.S. Department of Housing and Urban Development (HUD) Manufactured Home Dispute Resolution Program is available to resolve disputes among manufacturers, retailers, or installers concerning defects in manufactured homes. Many states also have a consumer assistance or dispute resolution program. For additional information about these programs, see sections titled “Dispute Resolution Process” and “Additional Information—HUD Manufactured Home Dispute Resolution Program” in the Consumer Manual required to be provided to the purchaser. These programs are not warranty programs and do not replace the manufacturer’s, or any other person’s, warranty program.”

If the state you are selling the home into operates their own dispute resolution program, check their requirement for consumer disclosure. If you are not sure, you get more information at

General Retailer Responsibilities:   I hope that all retailers of new manufactured homes print a copy and read Retailer Responsibilities, found at Sub-Part F, of the Manufactured Home Procedural & Enforcement Regulations. If you don’t have a copy, click Sub-Part F 3282 .  The three bullet points below summarize what you should know:

  • Retailer may not sell or lease or offer for sale or lease a new manufactured home that does not fully meet the HUD Code. 24 CFR 3282.252
  • Retailer must submit “Purchaser Card” to manufacturer. 24 CFR 3282.255 
  • Retailer must report ALL possible code violations to the manufacturer. 24 CFR 3282.256

Storing Homes on Retail Lots:  Since we are talking about retailer responsibilities, we shouldn’t forget retailer responsibility for homes that are stored at their sales or storage lots. Check the installation instructions that come with every home. They require the retailers to inspect and repair damaged shipping plastic to make sure the home is weather tight. If the home is on display, support at 12’O.C. along the main beams and sidewall/marriage wall openings 4’ or greater. You even need to install any roof vents.

Typical instructions from every manufacturer.

If the home is being stored  (no people going in and out) for more than 30 days, support the chassis 2’ from each end, and mid-way between tire/axle and hitch. 24 CFR 3286.11






For more information on these requirements, you can visit HUD’s website HERE  or their contractor SebaPro’s website: 


Exterior Coverings-Vinyl Siding

Let’s talk a little bit about vinyl siding. Even if you only install single section manufactured homes, there are still some vinyl siding considerations that you should know.

Creative! But not acceptable!

We can start with how to make a repair to damaged vinyl siding. Maybe the corner post had a close encounter with a telephone pole, or maybe the first course got scraped across a guide rail. The repair is simple! Remove the damaged section of siding and replace it with a new piece!  No, you can’t cut the nailing flange off of another corner post and slip it over-top of the damaged one. And NO, you can’t snap a

I wouldn’t want this on my home!

little piece over-top a hole or other defect or even use caulking to fill a hole. Damaged or defective vinyl siding must be replaced!


Probably the biggest mistake installers make is when they fasten the skirting starter channel to the home. There are two factors to remember when installing the skirting channel: 1. The siding has to be able to freely expand and contract with changes in temperature. 2. There must be no way for water to get between the siding and skirting channels.

I am beginning to see a lot of different approaches regarding the skirting attachment. Some good, some not so good. The recommended approach is to hang the skirting from a separate nailer that is attached to the floor of the home. Most installation instructions tell you to screw a 2 X 4 under the home to fasten skirting. Not easy to do!

OSB sheathing extends below siding for skirting attachment.

Typical in every installation manual

I have seen a few manufacturers extend the OSB wall sheathing below the first course of siding for skirting attachment. Several installers have told me that water seeps into the joint between the siding and skirting. To prevent this water infiltration, I suggest a simple “Z” shaped flashing, slipped under the siding and over the skirting channel to take care of that!

Bottom lap cut off.

Never cut off the bottom lap of siding to install skirting! I have seen this more than I care to admit. It is never a good idea.

Tie Down Eng. Skirt Hang-R

A new device is available that is definitely worth a look. Tie Down Engineering has come up with the “Skirt Hang R” that screws to the bottom of the floor joist for attachment of the skirting channel.

For sectional homes or other home designs that rely on the installer to finish the vinyl siding, there are several other things to consider.

Always remember that vinyl siding is NOT fastened to the home, it is “hung” from the home to allow for lateral movement. Do NOT drive the nails or staples tight against the material. Hang It Loose! Speaking of nails or staples, make sure they are corrosive resistant! Galvanized or aluminum nails and galvanized staples. If the home is new, the manufacturer will provide these fasteners with the ship loose material.

Generally, the siding should be secured at a maximum of 24” on center. Often the siding running under windows and doors will need to be secured by being snapped into under-sill or finish or utility trim using lugs you crimp into the siding. I know that many manufacturers don’t provide under-sill trim….but I think they should! 

Notches needed at top & bottom!

You should overlap siding joints between 1” and 1 ½”. A little extra overlap on hot days, a little less on cold days. Speaking of overlaps, if you have to cut off the factory cut edge, make sure you cut the notches at both the top and bottom of the siding to assure the siding can expand without restriction.

And as always, never just take my word for it. Check the instructions on the siding box and the manufacturers installation instructions!

Expanded Installation Checklist

Those of you who have attended any of my training courses over the past several years, know that I am a big fan of using checklists to document the proper installation of manufactured homes.

The Manufactured Housing Improvement Act requires that installers of new manufactured homes maintain records for at least 3 years. However, they don’t tell you what these records should look like. At a minimum, I have suggested installers use the “Complete Installation Checklist” (found toward the back of every manufacturers installation manual) as the basis for their record keeping.

I contend the checklist should be the most important tool for installers to not only use as a defense in the event of a legal proceeding, but to also help reduce the chance of call backs due to some little problem that may have been overlooked. It is just good business

But to be honest, the checklists provided in the installation manuals are pretty weak (see the example on the left).  So, I came up with a checklist that would hopefully function better for installers and become a more useful tool. It is attached to the bottom of this post for your use (both a word document and PDF). This checklist captures all of the items from the checklist provided in the manuals, and includes some important elements that are left out.   But here is what I think is the best part, the attached checklist can be customized.

You can download this checklist and make your own edits that will specifically work for you. Maybe you want to split it up and assign specific responsibilities to certain people. Maybe you want a checklist limited to single section homes. Maybe you want to make it specific for a particular anchoring system. The choices are yours.

Keep in mind, no checklist (including this one) can every cover every aspect of the installation process. But, I do believe that this goes further than what is currently available. As always, make sure you refer to the home manufacturer installation instructions for proper installation methods

So, have at it! Share comments should you see anything you think is in error or missing!  But most importantly, start keeping records and use some type of checklist!

Expanded Manufactured Housing Installers Checklist

Expanded Manufactured Housing Installers Checklist PDF

Exterior Coverings-Roofing

Shingles blew off due to improper fastening.

Now that Fall is here, I thought it might be the right time to start talking about roofing and siding on manufactured homes. If you check the Manufactured Home Construction & Safety Standards (3280.307) you won’t find a lot of detail. Basically, we need to use corrosive resistant fasteners (shipped from the factory for new homes) to attach an exterior covering that must prevent infiltration of air, water and vermin. 

Bottom line, the code requires that we install the exterior coverings to the product installation instructions. So, it is smart to read the shingle bundle  wrapper, the siding box, or the little instructional insert found in other products.

Let’s take a closer look at some of these roofing and siding products, starting at the top. Roofing! I am going to try and focus on issues that installers are faced with, and what I most commonly see in the field in regards to roofing:

1.       Shingles damaged by the factory installed wind deflectors.

I know you have seen furring strips nailed to the roof with so many nails or staples you can barely get a pry bar underneath to pull them free! Inevitably, the shingles get damaged trying to pull the strips off. And what do you do about the holes left behind from all of those nails? Here is the kicker, when a shingle is damaged, it should be replaced. There is no approved method in any of the installation manuals I have seen that show how to repair a shingle. If your manufacturer is shooting way too many nails in these strips, take some pictures and send them to the QC manager! And ask for a design for proper repair!

2.       High fasteners that prevent shingles from sealing together and allow wind under the tabs.

If the nail head or staple crown prevents proper sealing because it is not driven flush, the shingle can blow off or the fastener can even cut through the tab.

3.       Over-driven fasteners are just as bad! A nail head or staple crown that cuts into the shingle will surely lead to shingle flying off on windy days.

Hinged roof shingles not laying flat.

4.       Hinged roof shingles not lying flat.  You can’t assume that the shingles will lay down over time. The manufacturers rely on you for feedback on how the hinged part of the roof knits together. So, make sure you report any problems back to them!

Drip edge not projects past shingles.

5.       Drip edge projecting past the shingles. This is a problem when the installer has to install the last few feet of drip edge to reach the peak of the roof or along a hinged area. If you can’t slip the drip edge under the shingles so that there is at least ¼” of shingle past the drip edge, you need to report it to the manufacturer. Don’t cut the drip edge to go around a rogue nail or staple.

The other issue that I think we should look at is ice dam protection. To protect the eaves of the roof from water infiltration due to ice damming, manufactured homes produced for cold climates are provided with a type of ice and water shield. The Asphalt Roofing Manufacturers Association (ARMA) says that in areas where the average January temperature is 25° of less, ice dam protection is needed.  I typically see manufacturers use either a self-adhesive product, or they use a multi-layer application of roofing paper that is roof cemented to the roof decking and covered with a second layer of the same paper cemented to the first.

In both cases, the ice dam protection extends from the edge of the roof deck to a point 24” past the interior wall finish of the exterior wall. Should you be called upon to repair any damaged roofing along the eaves of the home, make certain you are provided the needed designs to properly correct the ice and water shield.

How Improper roof ventilation causes ice build-up.

The roof insulation blocking the vented soffit, could result in ice damming!

Generally the top reason an ice dam forms along the eaves of any home is due to improper roof ventilation! The HUD code requires that there be a 1” air space under the roof decking to eliminate cold spots that would lead to freezing of any water running down the roof. Should you have a home with ice dam issues, report it to the manufacturer and ask them to check the roof insulation!

Ok…next time we will talk a little about vinyl siding!

Piers You’ve Probably Overlooked!

I know that most professional installers are very conscientious when it comes to proper pier placement. But with all the variations in the installation instructions, some piers are often missed. Even while the manufacturers are required to identify “point load support areas” many areas are still overlooked.

One example of identifying point load locations.

Let’s take a quick look at some of manufacturers installation instructions to see where they do or do not require “point load” support piers.  


I started with the new Clayton Installation Manual to see exactly where they require point load support. They want supports at each side of exterior doors in the side wall. No support is needed if the door is on the end wall supported by a “steel header”. So, do we need supports if the door is at the tail end of the home if it doesn’t have a header? They go further and say no support in needed for doors in the side wall if the chassis I-beam spacing is 112”.

A support pier may be needed at through-the-rim crossover locations.

Support is also required at locations where through-the-rim joist heat duct penetrate the floor rim-joist.  I have seen this requirement in a few installation manuals, but not much further direction. I don’t know exactly where to position this pier, and I have never seen these areas identified as point load support areas on the underside of any home. 

A support is needed at each side of a factory installed fireplace when located along the side wall or marriage wall, (again with the exception of fireplaces supported by the front chassis crossmember). 

Adjustable outrigger at patio door location. Note the white paint marking the location.

The Clayton Installation Manual does allow adjustable outriggers to replace piers at the fireplace locations and door locations (less than 48”) along the marriage wall or side wall. The Clayton Manual doesn’t mention the use of an adjustable outrigger at the “through-the-rim” heat duct location. (check out page 21 on the Clayton Installation Manual).

So, just for fun, I decided to compare a few other installation manuals, starting with Champion.  

Window configuration creates side wall opening greater than 4′.

When it comes to doors, Champion is pretty clear (page 16). They require a support at each point load including: both sides of doors in the side wall. If the door is less than 48”, adjustable outriggers may be used in place of door piers. “Blocking” is not required for doors in non-load bearing end-walls.  

Here is an interesting one: Champion requires support “Under heavy (400 lbs or greater) items, such as heavy furniture, waterbeds, fireplaces and large fish tanks”. I better have a few extra blocks ready for the next visit from my mother-in-law!

Typical porch support.

What about Commodore/Colony you say? Ok, turn to page 15 in their installation manual. They want support at both sides of exterior doors at the side wall, but not at doors in the end walls. Porch posts always require support. They also want a support at through-the-rim heat crossover ducts, and under heavy items like waterbeds, fireplaces, and mothers-in-laws.  

Here is the curve ball: “…where marriage line openings are greater than 10 feet, intermediate supports must be placed at maximum 10 feet on center”. Some other manufacturers have this same requirement. Others only want these intermediate supports if the home has perimeter supports (evenly spaced under the side walls).

T Brace (pier saver).

I think it’s only fair to say, that Commodore/Colony was the first manufacturer I was aware of to introduce “Pier Savers” for support of patio and other exterior doors! I am a big fan of pier savers.  Look up their “Alternate T Brace” addendum A-7.

Adjustable Outrigger

Skyline requires a support at exterior doors on side walls (not end walls), typical 4’ marriage line and side wall openings, through-the-rim crossover ducts, porch posts, heavy furniture, fireplaces, etc. BUT..Skyline utilizes the adjustable outriggers more liberally than most. Basically you can use an adjustable outrigger to replace a support with a load up to 1,700 lbs. Go to their charts on page 20 of their installation manual for span loads. Some Skyline plants provide the adjustable outriggers with the homes. Make sure you get a copy of the “Addendum to Installation Instructions for Installation of Adjustable Outriggers”   

Shear wall strap needs pier support.

Finally, I checked out Fleetwood, pretty similar to the others, except they want support at “labeled G-2 strap locations” (see page 20 in their installation manual)

At this point you might be thinking, “just follow the pier print”. Well, I checked out a handful of “pier prints”, and most of the locations mentioned above are NOT identified on the pier prints. None showed the piers at the through-the-rim crossovers, or at any fireplaces. Also, the “intermediate” supports at the marriage line is missed by most. One pier print I noticed shows piers that defied any reasoning!

OK, here are the take-aways:

There is no “One Size Fits All”. Make sure you take 30 seconds, and open the installation manual and look under the heading “Install Footings” where you “Determine Locations”. Make sure you know each particular manufacturer’s variations.

Don’t trust the pier prints! Never, Ever! Follow only DAPIA stamped (approved) designs and instructions.

Investigate pier savers and adjustable outriggers! Some manufacturers already approve their use. If yours doesn’t, start asking for approval! The squeaky wheel always gets the grease.

And lastly, don’t invite my mother-in-law to your house!

Talking About Manufactured Homes, Post Harvey & Irma

Over the past few weeks, our industry has received a considerable amount of attention from the media and emergency management agencies. Unfortunately, most of the attention hasn’t been favorable.  Now is the time to refocus the attention on manufactured housing that is completed by professional installers, and meets or exceeds the various elements of the Manufactured Home Construction & Safety Standards (HUD Code), to provide not only affordable housing, but housing that is durable, high quality and above all, safe. Let’s discuss a few facts that you can share with your customers and the general public: 

  • There has not been a “mobile home” produced in over 41 years. You are installing and/or selling “manufactured homes” and the difference is significant. Don’t diminish the immense improvements that have been made by the industry since 1976. Use the proper terminology!
  • The HUD Code takes wind storm protections very seriously. The country has 3 different wind zones to address areas susceptible to wind hazard. Wind Zone II requires homes to be designed to accept 100 MPH winds. Wind Zone III’s design load is 110 MPH.
  • The anchoring process for manufactured homes has been completely revolutionized since 1976. There are newer anchoring systems available that not only meet the code requirements, but they are considerably easier to install and less susceptible to problems from site grading, frost heave or other environmental problems.  If you haven’t re-examined your anchoring procedures, you need to immediately. Look at a previous posts on this topic.  Introduction to Alternative Anchoring Systems
  • Every new manufactured home sold today is installed by a trained professional. And every installation is required to be verified for proper installation by a building code official or similar code enforcer.

Much of the destruction caused by Hurricanes Harvey and Irma was beyond the ability of any residential building code. Many homes sustained damage from impact of flying debris and flooding, as opposed to wind storm. Did you know you can equip manufactured homes with hurricane shutters to protect large windows and glass doors? Check the home installation instructions under “Complete Exterior Work” or visit for more information (search for hurricane shutter designs) .

In far too many cases, manufactured homes were damaged due to the failure of carports, patio covers, awnings, and similar after-market additions that catch the wind and impose pressures on the home well beyond the intended design load. I am sure you all know that these types of accessory structures must be independently supported. If you haven’t already, watch this video, Click Here, it clearly illustrates the problems that attached structures can cause.

Remember, the HUD Code is a minimum code. Have you considered offering your customer the next step up? Offering a middle snow load in the south zone? Offering Wind Zone II in Wind Zone 1?  A higher level of performance is a feature that can be easily marketed, and may be instrumental in changing the narrative. Not every buying decision is based in the lowest price. Give your customers options and they just might choose a higher level of performance.

I think the time is right to start talking about the improvements that have been made over the past several years. If we continue with a mobile home mentality, the media and public will remain skeptical of our industry and never learn about these important changes and high level of performance and safety a properly installer manufactured home can deliver!

Water Heater Temperature & Pressure Relief Valve Discharge Pipe

A few installers have raised a question about the discharge pipe for the water heater Temperature and Pressure (T&P) relief valve. Ultimately, should the water heater T&P discharge pipe be run to the exterior of the crawl space? 

I did a little research and quickly discovered that this issue needs much more discussion than is provided in the manufacturer’s installation instructions, or that we can accomplish here! But we should start thinking about it.

The first thing to understand is the job of the T&P valve. If the temperature in the water heater reaches 210° or the pressure reaches 150 psi, the relief valve will open reducing the pressure or releasing heated water to be replaced with cold water. This is  to prevent a potentially catastrophic failure. Just image the power that can be generated when the water starts to boil inside the tank! There have been reports of water heaters exploding and propelling themselves through the walls causing significant damage to the home.

The amount of heated water that can be expelled through the T&P discharge pipe can range from a trickle to a gusher! Either way it enough to cause severe burns!

The manufacturer’s installation instructions don’t offer much guidance. I reviewed several “Complete Installation Checklists and they all state “Dryer vent, range/cook top exhaust, water heater temperature and pressure relief overflow pipe and AC condensate drain installed to the perimeter of the crawl space”.

If you look a little deeper in the manufacturer’s installation instructions, several state “If the home is to be installed on a basement or enclosed crawlspace, install the drain pipe connecting the discharge from the water heater temperature and pressure relief valve to the outside or to a sump”. I did find a few exceptions that clearly state that the T&P may discharge under the home. But bottom line, there is no consistency in the various manuals, and no direction as how to safely extend this discharge pipe to outside of the crawl space.

In my opinion, the installation of vinyl skirting around the perimeter of the home meets the criteria of a crawl space, and I have yet to see any definitions that say differently. So, I guess they are saying to run the T&P discharge pipe outside the skirting.

T&P & water heater pan pipes discharging under the home.

Finally, I double checked the Manufactured Home Construction and Safety Standards (245 CFR 3280.609(c)(iii). It says the “relief valve outlet which shall be directed downward and discharge beneath the manufactured home”. 

So, what should a professional installer do?

If you should decide to extend the T&P discharge pipe to the exterior of the crawl space, keep these things in mind:

The T&P pipe should have an elbow directing any discharge downward.

Any water being discharged from these T&P valves is extremely hot with the potential to cause damage to people, pets or property in the area. Make sure the pipe points downward to about 6” above grade to reduce the possibility of injury! Make sure it is visible, but away from an area where people or pets might be injured.

Any extension of this pipe must be the same size as the discharge pipe attached to the valve. Keep the piping as short as possible (less than 30’ total length), with as few elbows as needed (four elbows are the maximum permitted).  Any horizontal sections must slope away from the valve. Do NOT install a trap, shut off valve, or a cap on the discharge pipe!

Never connect the T&P discharge pipe to the DWV (drainage) system of the home. Should the valve become defective, the occupant would never know, and in the event of a violent discharge, the DWV system could be damaged and people possibly injured. Not to mention possible contamination of the water supply!

I suggest a discussion with the local code enforcer to get his take on this issue. Also, review the water heater instructions and see what they say. Contact the home manufacturer’s engineering department for their input as well.

Unfortunately, there may not be a simple, straight answer to this question. But maybe this discussion will help us to make the best decision to assure the safe operation of these water heater T&P valves.

I would appreciate hearing your comments on this issue!