Plumbing in manufactured homes can be a great DIY project. As long as you can work with tools and understand the basic concepts of the plumbing system, you should do just fine.

A manufactured home plumbing system is a more simplified version of a stick-built home, but that simplicity is not a bad thing, those differences makes everything much more accessible and easier to work on. 

down the plumbing drain

Down the Drain by Alex Beltechi.

Differences Between Plumbing in a Manufactured Home and Stick-Built Home

Manufactured home plumbing systems are a little different than stick-built homes. The main water supply connection is usually found under the edge of the home, near your outdoor hose bib (where you connect your garden hose). The supply lines are usually housed in the middle of the home or on the side, depending on the layout and location of your water heater. Plumbing pipes are rarely housed within the walls of a manufactured home, but are stubbed straight through the floors under the sinks.

Some manufacturers may have used the lightest, and often the cheapest plastic piping or galvanized metal, so replacement will be needed eventually in older homes. Galvanized pipe is known for rust issues and and the plastic piping (polybutylene) are known to corrode and cause leaks. There’s also issue with the connections. If you find yourself plagued with leaks, go ahead and re-pipe the home, if possible. In the end it will be far cheaper, and less stressful, than trying to fight with old material and patches. Area plumbing codes will be the ultimate factor in deciding what material to use but Pex seems to be a well received product, as long as the connections are high quality and a proper seal is made.

Clean outs and overflows are not used very often in a manufactured home, though there is still a ventilation stack or soil stack as I’ve heard some call them. The stack is a small pipe sticking out of your home’s roof and carries the bad fumes and gases from waste away from your home. You have to have one for your plumbing to work properly.

Know How to Turn Your Water Off

You need to know where and how to turn your water off  in case of an emergency, or before any repair. Being able to shut your water off quickly can be the difference in a complete disaster and a small inconvenience.  The main stop valve should be around your outside garden hose water connection (hose bib as some call it) and most are easy to get to on a manufactured home.

If you can’t find you connection, then you need to be able to cut your water off at the source: at the main water meter (assuming you are on a city system) or in your pump house if you are on a well system. If you are on city water you will need to own a water meter key in the shape of a five-sided pentagon to remove the cover. They come in different sizes so make sure you buy the right one. You can also use a wrench and long screw driver for a makeshift key – place a wrench on the vertical (or straight up and down) and the thread the screwdriver through the whole at the end of the wrench. The two tools will look like a T. Use the screwdriver to turn the wrench. This article about turning off your water supply is handy if you want to read more.

water-meter-cover-security-

water-meter-shutoff-valve

FYI:  It is smart to have cut off valves at every water source (faucet, tubs and toilet) however, if you have to repair or replace a supply line anywhere within your home, you must cut the main water supply off. There’s a lot of pressure in those lines and it needs to be reduced before you start cutting into them.

 How Basic Plumbing System Works 

Basically, there are 3 parts that make up the whole plumbing system. Supply lines do exactly what they say they do,  supply the water. The next component is the drainage lines and they drain waste. Simple enough, huh? The last part is the ventilation lines

Your water supply lines are the smaller pipes (3/8-1 inch) that come into the home. They are usually either copper or Pex. If your home has white, cream or a medium grey pipe for your supply lines, you will probably want to replace them as most local regulations don’t recommend them and some have banned them altogether. The water comes through 1 line and then branches at the water heater so some water can get heated, from there a hot and cold line runs parallel to the faucets, tubs, etc.

Your larger pipes (2″-4″) will be your drain lines. Drainage lines use gravity, traps and ventilation to ensure the optimum waste removal and keep gases and fumes from building up and releasing. Think of this as a completely closed system with positive and negative vacuum or pressure. All the parts have to work correctly to allow the system to do what it is designed for. Without the proper positive or negative pressure acting as a vacuum in the pipes the waste won’t go where it’s supposed to, it can back-flow instead.

Drain pipes are usually made from copper or PVC.  You have to get the grade right on drainage pipes because to much of a grade (or slant) will cause as much issue as to little. A 1/4″ to 1/2″ grade per every foot is ideal.

Ventilation Pipes

Ventilation pipes ventilate and help the waste keep the proper pressure or vacuum – in other words, it keeps water in all the right places.  It is just as important as the supply and drain lines and you have to have ventilation in order to make it all work. Plumbing systems are much like a living thing – it has to have air and water.
A single ventilation pipe in a manufactured home won’t help the drain pipes furthest away so they use what I’ve always just called a dry vent (they also call them auto vents, check vents, or air admittance valves). These vents allow air flow into the drains. Keep in mind that oftentimes a dry vent on a sink isn’t necessarily helping the sink it is tied into, it’s benefiting the other drains in the house. If you would like to learn more about auto vents, this article does well explaining, as does this one.

check vent

Source: mobilehomerepair.com

Remember that water is coming into your home under a lot of pressure through your supply lines. It can turn corners and go up several stories. If you have a leak in the system, imagine how much water can be lost in just a small amount of time! It really pays to be proactive and do a monthly plumbing check. Drainage leaks are sneaky little things. Water will always follow the path of least resistance so sometimes it’s hard to pinpoint where the leak is coming from.

Here’s the simplest schematic I could find to show you:

Roughin plumbing diagram ask the builder

Know Your Plumbing Pipes

You will need to know what type of pipe and fittings are used for each sub-system. There are basically 2 types of piping used in plumbing- metal and plastic. Most plumbing in manufactured homes use plastic. Plastic pipes include polyvinyl chloride (PVC), chlorinated polyvinyl chlorine (CPVC), PEX pipe and PolyPipe®.  Metal plumbing pipe consists of copper, stainless steel and galvanized steel. Not all pipes are as useful or effective as others, and each type is used for a specific purpose in plumbing.

Polybutylene Pipe

Polybutylene was used in all types of homes, including manufactured homes, from the late 1970’s to the mid-1990’s. Several lawsuits were filed on behalf of millions of homeowners due to issues this material had. If you had any type of bleach in your water, and most city systems do, the pipe would break down and cause leaks and complete blowouts, usually within 5-10 years. You can’t buy it anymore but it’s still in more homes than it should be. It’s a medium grey color and will have PB and some numbers on the side. If you have this in your home today, you need to replace it and then go buy a lottery ticket cause you have been very lucky to have had it this long without any issues!

If you are looking to buy an older manufactured home, do not buy it with this kind of pipe in it. Make the seller replace it or have them take the replacement cost off the price of the home (there may even be local and federal laws prohibiting the sale of a home with this type of pipe in it).

PVC

PVC is a type of plastic plumbing pipe primarily used to transport high pressured water. It is available in several standard sizes, ranging from ½ inch to 4 inches in diameter. PVC pipe is only made to handle cold water, as hot water will cause the pipe to warp. It is generally white in color, though a few varieties are gray.

CPVC

CPVC pipe that has received an extra chlorination. It comes in a distinctive yellow color, and can handle both hot and cold water. CPVC is more flexible with substantially thinner walls than PVC pipe, and has the same outer diameter as copper pipe, which increases it’s range of uses.

PEX

PEX, also known as cross linked polyethylene pipe, was first manufactured in the 1920s, but has become more popular in recent years. It shares the same outer diameter as copper, and can be used for both hot and cold water. However, PEX pipe has a much higher heat resistance than most other plumbing pipe, and is often used in water-based heating systems. It comes in a creamy white color, as well as red and blue which is used to denote hot and cold pipes respectively.  I, and my husband who has been a master plumber for 18 years,  absolutely recommend you replace your water lines with PEX when the time comes to update. You can use special fittings to secure the connections by hand or rent the tool needed to connect the lines. Pex, in our humblest of opinions, is the best pipe for water supply lines and is so much easier to install than anything else.

PolyPipe®

PolyPipe is a thick black pipe used to transport highly pressurized water, usually to and from the home. It is used almost exclusively outdoors, and is usually buried underground to prevent freezing. PolyPipe® is extremely rigid, and is rarely used for other purposes.

Here’s a good video about a double wide re-pipe:


Copper

Copper is the most common type of plumbing pipe used in the home, although it is more expensive than plastic piping. Copper is especially resistant to corrosion, and can withstand high temperatures. Copper pipes come in three different sizes – type M, L, and K. Type M has very thin walls, while type L is of medium thickness, and type K is the thickest of the three.

Stainless steel

Stainless Steel pipe is less not as commonly used as other metal pipes, as it is more expensive and harder to find. It is primarily used in marine environments because it can withstand salt water, which would erode most other metal pipes. The price makes it less desirable for other applications, or in safer areas where a copper pipe would perform just as well.

Galvanized

Galvanized pipes have been used in homes for years, typically to carry water in and out of the house. The galvanized coating prevents rusting, and gives a dull gray appearance. Use of these heavy duty pipes is diminishing, as it is being replaced by PEX pipe, which is less expensive and just as durable. Galvanized pipes typically come in sizes between ½ inch and 2 inches in diameter.

Nasty smells and weird noises

No, it’s not your teenager. 

Notice the yellow vent lines in the schematic above? It’s the small pipe sticking out of your roof. There are wet vents and dry vents, the roof pipe is considered a wet vent. Without proper ventilation, you will encounter several issues. The worse being nasty fumes and a build up of gases that could cause some serious issues.

Ventilation makes your pipes remain at a neutral pressure. Without proper venting your drainage slows and the water in your P-trap goes away, which in turn releases the nasty gas/fume combination.

If you hear weird sounds coming from your walls you most likely have a venting problem. Think of a soda bottle: when you tip it half way, the liquid smoothly flows but when you turn it completely upside down, it makes gurgling sounds and the soda pours out slowly. That’s what happens when there’s not enough ventilation or air flow. If you have ventilation issues you can fix it yourself fairly easily.

Leak Law..

Water is one of the most destructive forces on earth. It will always flow the path of least resistance. Plumbing in manufactured homes will rarely be inside a wall so you won’t need to worry to much about damage to walls, it will be floors that get the most of the damage and then just spread from there. Most plumbing pipes run under the home and up through the floors. A monthly check under your home is a good idea. Your flooring is most likely made of a composite wood and that stuff loves water – it just soaks it right up and eventually bows and rots.

Plumbing Problems

Leaks, clogs, low pressure, obnoxious odors and having no hot water are just a few of the issues that you may encounter. If your manufactured home is older you may have to replace the system entirely. There’s lots that can go wrong! We’ll try to cover them all in the future. 

Leaking Faucets

Leaking can occur in a couple of different places on a faucet. It’s probably easier to just replace the whole unit than repairing. If you are especially attached to your faucet, this article about fixing leaking faucets should help.

Clogs

If you have a clog in your sink, a plunger can work well. They make a smaller plunger for the task. If you have a two sided sink, close off one side by stuffing a rag into the drain (cut off air) and plunge the other side, then switch – keep doing it until the clog is gone.

If you have clog issues frequently, it may be time to find the underlying issue. You can remove your p-trap, if its closed off with grease you can clean it out or replace. You may need to add a dry vent to the next closest sink.

If You Do Need a Plumber..

If you do need to call a professional plumber, my best advice is to ask every plumber, and any construction worker for that matter, if they actually passed the licensing exam or if they were grandfathered in.

If they say grandfathered, get a different plumber. I’m serious. 

Allow me to explain: Here in WV and a couple other states I know of, they initiated a law making everyone on a construction site to carry a license. They offered 3 types: apprentice, journeyman and master. However, when the law first took affect, they gave everyone  a time frame to apply and automatically receive the license as long as they paid the fee and signed a paper ‘confirming’ you had the experience needed to qualify for one of the three licenses. No one had to take an exam to prove their knowledge. Now, the state has hundreds of so-called master carpenters, electricians and plumbers that aren’t as knowledgeable as they should be.

Also, ask for references and actually call and ask them how the job went.

I hope that helps you. If you have any questions please feel free to ask them in the comments. My husband would be more than happy to answer any questions and yes, he took the exam to prove his knowledge.  ;)

Thanks so much for reading Mobile & Manufactured Home Living!


About The Author

Crystal Adkins
Creator/Author
Google+

Hello! I'm Crystal, the creator of Mobile Home Living and I appreciate you stopping by! I hope MHL is an inspiring and informative resource for you! Please consider letting us feature your remodels, room makeovers and home improvement projects. There's simply not enough inspiration available for manufactured homeowners and I want to fix that. Thanks!

15 Responses

  1. Godmund

    My parents bought a mobile home and now they have all these plumbing problems. This article set me on the right path.

    Reply
    • Crystal Adkins
      Crystal Adkins

      I’m glad it helped. I really need to learn to write better though..lol. If you have any specific questions or just need some advice, just comment back and we’ll do our best to help.

      Thanks!

      Reply
      • Penny

        Yes, I need help. I own the mobile home, but not the land and the landlord has told me to fix my leaky galvanized pipes or he will shut the water off to my mobile completely. I have to do this myself and I’m not a strong female, but I am a determined one. My question is .. How do I get the galvanized pipe off this mobile home?? I have to replace it with PEX – but the pipe was done in 1969 and it’s really wrenched on to connections. Can I cut it?? I can’t possibly cut thru it with a hacksaw, I’m not that strong… any ideas. It’s getting late in the year and the snow will fly soon and I will not have any water.
        Thanks so much

      • Crystal Adkins
        Crystal Adkins

        You can cut it Penny! If you have access to a sawzall that would probably be your best bet, there are blades you can buy just for the pipes that will saw right through them.

        You shouldn’t have too hard a time installing the PEX. It’s great for DIY beginners and you just about can’t go wrong with water lines. Look into using the shark bites for the PEX, you can just hand tighten them and get a good seal – I think they are the best invention ever! Now, if you have to replace the drain lines too, that could pose a bit of a hassle but nothing you can’t handle!

        My email address is crystaladkins@mobilehomeliving.org. If you need anything just email me directly -my husband is a master plumber and we’ll be happy to help you and walk you through it all. Together we can make sure you have water!

        Thanks!

  2. brenda

    we keep getting broken pipes, ready to rip my hair out, i begining to think we bought a money pit!!!!!

    Reply
    • Crystal Adkins
      Crystal Adkins

      Hi Brenda!

      Sorry you’re having issues! There’s got to be an underlying cause for the broken pipes – usually it’s either the pipes were faulty from the get go, their just old, the pressure is too high from the main line or the pipes are freezing and busting.

      If it’s an older home or the pipes are just faulty, you’ll probably just need to re-pipe the entire home. It will save a lot of time, money and frustration over just fixing the leaks as they happen.

      You could do it yourself for less than $100-150 in material. A roll of PEX with the proper fittings is about all you need – they make fittings that you just push into the pipe and they also make transitional fittings so you won’t have to replace your faucets connections. One day of labor should do it! Run the pipe as close to the middle of the home as possible and insulate it well, that should help with freezing. If your water has very high pressure, you might want to look at your pressure reducing valve. It lowers the pressure from the main water line before it goes into your home. The pressure is very high from the main line and if it’s not reduced or controlled it will cause the connections to fail quicker.

      If you have any specific issues just let me know! I’ll do my best to help. Good luck!

      Reply
  3. Debbie

    Is the water line running in the belly skirt? Or underneath? We came home today to find water under the laminate flooring in the kitchen, not pouring out, but when you step on the laminate some squeezes out through the cracks. It seems to me that if the pipes are leaking then the water would leak into our crawlspace not up into the house.

    Reply
    • Crystal Adkins
      Crystal Adkins

      Debbie,

      Yes, most water lines in manufactured homes run under the home but the water lines come up through the floor and connect to your faucet. Please look under your kitchen faucet or dishwasher for the leak. That connection may very well be the problem.

      If you’ve experienced a lot of snow or rain, if could be a leak around doors or windows. (The heat from the home could be melting the snow on the roof and traveling down a wall). You’ll want to shut your water off immediately either at the connection point, usually where your water hose connects outside or at the meter or well/pump. If it’s that bad (and that’s a pretty bad leak if it’s squeezing out) then your sub-flooring and walls will get water-logged and weaken the wood or it could cause mold issue later on. First, find the leak and fix it. Then lift the laminate and soak up as much water as possible and point fans to it. You don’t want the water to ‘sit’ on the wood for very long.

      So sorry you are experiencing this! If you need specific help please send me an email to crystaladkins@mobilehomeliving.org and we’ll do our best to get you pointed in the right direction. Good luck!

      Reply
  4. Anita Garmon

    Hey Crystal,
    I have a 1996 General double wide mobile home and I noticed water damage to some of the walls in the home in 2008. I had a plumber come out and he said that I don’t have any water pipes on the side of the house where the water damage is. He had me turn on the water while he was under the home to check for leaks on the opposite side of the house where the pipes are at and he said there were no leaking pipes. He suggested that it may be coming from the roof so I had a new roof put on in 2010. The areas where the water damage is is still wet. So I had another plumber come out and he could not find a leak either. The water damage is in 3 rooms of the house and it starts where the carpet meets the wall and goes up about 6 to 8 inches. There is a hot water heater in one of the bedrooms and that bedroom is adjacent to the rooms that contain the water damage. Any ideas or suggestions on where the leak is coming from would be greatly appreciated.
    Thanks,
    Anita

    Reply
    • Crystal Adkins
      Crystal Adkins

      Hi Anita!

      I think you are experiencing humidity condensation from the ceiling or under the home. Believe it or not, condensation can often look and act just like a leak and produce enough moisture to rot walls and flooring. Make sure there are at least a couple of vents that allows air circulation to get to the area between your original roof and the interior ceiling. Sometime the vents aren’t properly setup during installation or sometimes when a new roof is added the installers cover over them accidentally. Are you seeing any warping in the ceilings anywhere? Maybe a little bow somewhere?

      That would be my guess if plumbing was ruled out as well as any possibility of leaks occurring from the roof or windows (or gutters). There’s also a chance that it could just be faulty, or no, exterior sheathing. My father bought a 1986 double wide brand new and when they delivered it it didn’t have one bit of exterior sheathing. It was vinyl siding, studs, and insulation…lol He assumed that it was a standard option but found out that it wasn’t. Lesson learned I supposed..lol

      It has to be something causing the damage, if the plumber checked the water heater, and all the lines are on the other side, then I would have to say its either condensation or water getting under the siding somehow (at the roof, widows, doors, etc). It could be entering at one side of the home and following along horizontal stud till finally appears at the carpet line. It could also be condensation under the home (if the vapor barrier under the home is ripped or torn, condensation can collect under the flooring).

      It really could be anything but I would look into the condensation above or below and a leak somewhere that’s allowing rain in. Good luck!

      Reply
  5. Karen

    Great site, we have a 1994 Fleetwood with the grey pipe, never had a problem (knock wood) but now the shower is dripping from the shower head. We have replaced the valves & seats in the past & the dripping stopped, this time with new valves & seats both generic & Phoenix brand the drip increased….called plumber & he wouldn’t even look at it to see if maybe my husband did something wrong, just wanted to cut the wall in my bedroom open & also cut fiberglass in shower stall & replace with Moen valve assembly to the tune of $850….this cost us $59 for that bit of devastating news. We put the old stuff back in & the drip diminished to almost very little as it was when we started. I don’t understand (1) why the new parts make it worse (they are same as old) & (2) why we were not offered any alternative to a total in the wall replacement.
    Thanks for any advice.

    Reply
  6. shiela

    I believe i have a ventilation line issue, after reading your information. I have water that is draining from washer coming out of roof. Could you tell me how to fix this problem?

    Reply
    • Crystal Adkins
      Crystal Adkins

      Hi Shiela! You may have a stoppage in your drain line from your washer where the water has no where else to go but up and out. See if you can borrow or buy a snake (its a long metal hose that you put down in the pipe and turn a handle to make it longer, you can buy a small one for less than $30 at Lowes).

      I think that will fix you right up but if you need anything else just let me know. Good luck!

      Reply

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