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New backflow preventer testing requirements

One huge change that came with the new Minnesota State Plumbing Code that went into effect on January 23rd of this year was the requirement for annual backflow preventer testing. Here's the exact code language for this new requirement, which can be found under section 603.4.2:

603.4.2 Testing. The premise owner or responsible person shall have the backflow prevention assembly tested by a certified backflow assembly tester at the time of installation, repair, or relocation and not less than on an annual schedule thereafter, or more often where required by the Authority Having Jurisdiction. The periodic testing shall be performed in accordance with the procedures referenced in Table 1401.1 by a tester qualified in accordance with those standards.

To make it simple, homeowners with testable backflow devices are supposed to have them tested by a certified tester annually. The most common testable backflow device found at Minnesota homes is a pressure vacuum breaker, which is a device that is found on nearly every residential lawn irrigation system (aka sprinkler system), shown below.

Pressure vacuum breaker

Sometimes this device can be found mounted high up on the side of houses because it must be located at least 12" above the highest sprinkler head.

At the time that I initially blogged about some of the upcoming plumbing code changes, I wasn't sure exactly what this particular change was going to be all about, so I only touched on it briefly. I didn't completely believe that such a costly and labor-intensive change would be coming, but the Minnesota Department of Labor and Industry has put together a fact sheet  ( making it clear that this is really what's required. These devices need to be tested annually by a certified tester.

How are municipalities enforcing this new requirement? I don't know, and it seems that most municipalities don't either. This requirement is still too new for everyone to know exactly how it's going to be enforced. It sounds like municipalities are going to start keeping track of all new installations, and will start sending out reminder letters to homeowners who don't comply. If you already have an existing installation, you probably won't be required to do anything about it.

The person who does the testing must be a certified backflow tester. Not all licensed plumbers have this certification, and a plumbing license is not required to obtain this certification. I've checked with a few plumbers, and the prices quoted for backflow testing ranged from $150 - $250, but I would expect the price to be significantly less from backflow testers who are not licensed plumbers.

Side note: while pressure vacuum breakers are the most common devices used for sprinkler systems, they not the only devices allowed. A reduced pressure zone (RPZ) backflow prevention assembly is also allowed, and can actually be installed in the basement instead of at the outside of the house 12" above the higher sprinkler head. This never happens on residential installations, however, because RPZs need to be tested annually... but now that new PVB installations need to be tested annually too, it seems that an RPZ might be a more atractive option. Another reason to use an RPZ is that they no longer need to be re-built every four years, which the old code had required.
RPZ Assembly

The other common place that a homeowner might have a testable backflow prevention device is on the water supply piping to a steam or hot water boiler.  The Minnesota State Plumbing Code used to require a dual check valve with an intermediate atmospheric vent as the lowest level of allowable protection for the water supply line to a boiler. These devices were commonly called "9D" valves, but the new plumbing code doesn't mention this type of device at all; per section 603.5.10, boilers must be protected by either a testable double check valve backflow prevention assembly, or an RPZ valve (pictured above). Despite this, the city of Minneapolis is allowing the old non-testable dual check valves on 1 and 2 family residential buildings, and I heard a rumor that this section of the MN state plumbing code might get amended to no longer require testable backflow preventers. See the Minneapolis memo on backflow preventers for boilers.

backflow valves for boilers

In summary

If you're having a new lawn irrigation system installed, you'll need to have the backflow valve tested every year going forward. If you already have an existing system, this won't affect you unless you have the valve replaced. This new requirement probably won't affect homeowners who have boilers.

Author: Reuben SaltzmanStructure Tech Home Inspections


Camera buying advice from a home inspector's perspective

I've gone through numerous digital cameras and I've become quite opinionated about what features a home inspector should look for in a camera. I recently sent an email to one of the newest inspectors on my team, giving some camera buying advice. Once I was done with that email, I realized it would make for a good blog topic as well. Even if you're not a home inspector, some of this advice might be helpful.

Side note: digital cameras have made life a lot easier. Back when I started with Structure Tech in 1997, my dad and Duane would take photos during their inspections and then drop off film to the office at the end of the day or early the next morning. A local photo shop would pick up film from our office in the morning and drop off developed photos in the afternoon. I'd glue the photos onto sheets of paper, enclose them in clear protective plastic, and include them in a binder with our inspection report, which I'd mail at the end of each day. The Sony Digital Mavica changed all that at the end of 1997. They were $500 and the high-res setting took photos at measely 640x480 pixels and stored them on a floppy disk, but we couldn't get our hands on them fast enough. They saved us a ton of time and money. Sony Mavica FD5


I recommend using a mid-sized camera that feels good in your hand. The opposite of an ergonomic camera is any camera shaped like a bar of soap that easily slips out of your hand. This camera will be easy to drop, and you'll drop it and break it. I know that many home inspectors prefer small cameras like this because the camera will easily slip into a front shirt pocket, but too bad. I'll take ergonomics over size any time. Ergonomic and not ergonomic

Oh, and think about cold weather and gloves if you're in a cold climate. Using a tiny camera is especially frustrating while wearing warm gloves. A larger camera with a big button is easy manageable.


The more the better. This surely goes without saying, but optical zoom is the only thing that should be considered. I've been using a camera with a 30x zoom for the past eighteen months, and I can't see myself going back to anything with a lesser zoom. I used to use binoculars to inspect chimneys and roof coverings that I couldn't safely access with a 28' extension ladder, but now I simply look at the zoom on my camera and take numerous photos from the ground to review on a computer screen later at home.

Check out the photo below, taken with a 30x zoom; I was experimenting with my last camera shortly after I purchased it last winter, and I took photos of a house across the block that was having a new roof covering installed. Once I got home, I happened to notice that the installation instructions on the underlayment weren't being followed. The instructions said "Use ONLY Plastic Cap Nails or Plastic Cap Staples". Looks like someone was using regular staples, yes? This wasn't the house I was inspecting so it was none of my business, but I thought it was pretty crazy to be able to identify the wrong fasteners from the next block over. Click on the photo to see a larger version. Roof Installation Observation


I wish there was some spec to compare that would tell me how well a camera could light up the far side of an attic while taking a photo, but there's no such thing... at least not that I've been able to find. The best way I've found to determine how well a flash will light things up is to simply look at the size of the flash. The larger the flash, the more light.

The flashes that are always exposed are typically the smallest. Pop-up flashes always seem to put out more light, so look for a pop-up flash. I don't like spring activated flashes, and especially not motor-activated flashes. Those are just two more things that can fail, and I've had both of them fail. The best flashes are the pop-up types that are manually operated. You simply set your camera to always flash when the flash is open, which makes it very easy to control when the flash goes off and when it doesn't. It just takes a quick flick of your finger to open or close the flash, and this can easily be done with big gloves on.


Macro flower

As far as I know, all cameras have a "macro" setting, which is what is used for taking close-up photos. This is what the universal flower button on cameras is for. Some cameras have a manual macro setting and some are automatic, but every camera I've ever owned has had this setting. What home inspectors need is the ability to use the macro setting in conjunction with the flash on their camera. Some cameras do an excellent job of this, while other cameras completely white-wash everything with the flash, rendering the photo useless.

I regularly use the flash along with the macro setting when taking pictures of data plates on appliances, and while taking photos of the insides of electrical panels. When I find carpenter ants, I take close-up photos of them too, simply to document their presence.

Carpenter Ant

To figure out if a camera will do a good job of this, you need to play around with it in a store. Try holding the camera about 6" away from something with small print and take several photos while using the macro setting and the flash. If any of the photos turn out white-washed, keep looking for a different camera. Many years ago I owned a Sony DSC-H20, which was the best camera I've ever used for taking great close-up photos every time. When that camera broke and was no longer made, the next closest camera that I could find was a Sony DSC-H90, but the macro-shots were inferior. Nothing I've used since has been quite as good, but I've had decent results with a Canon SX170 and a Canon SX400. All of these cameras have been in the $150 - $200 price range.

While you're at it, test out the zoom feature in the store. Some cameras don't focus properly when zoomed. Some do.


While many home inspectors like to purchase "tough" or "indestructible" cameras, I recommend simply purchasing an accidental damage warranty plan. Rugged cameras are too expensive, the zoom sucks, and the quality is compromised too much to justify using them. With an accidental damage plan, you can get your camera repaired or replaced for free, or for a small deductible. Best Buy has offered this for a long time, but accidental damage plans are also offered by SquareTrade, SmartGuard through Amazon, and a relatively new warranty company here in Minnesota called Upsie. I haven't tried Upsie yet, but I had a positive experience with a dropped laptop that was warrantied by SquareTrade. They simply mailed a check to cover the cost of the laptop.

Author: Reuben SaltzmanStructure Tech Home Inspections