2014 March-April

Cast Iron Piping Benefits By Francesca Dunbar We have to make choices every day. Personal preference seems to dominate over objective reasoning and we get complacent in our decision making. When it comes to drain, waste and vent (DWV) plumbing systems there is an ongoing debate over which is a better solution, iron or plastic.  Read more

Cast Iron Piping Benefits

By Francesca Dunbar

We have to make choices every day. Personal preference seems to dominate over objective reasoning and we get complacent in our decision making. When it comes to drain, waste and vent (DWV) plumbing systems there is an ongoing debate over which is a better solution, iron or plastic.  Both products have their advantages and disadvantages. Designers and contractors are experiencing tremendous pressure to value engineer projects. Most builders are not willing to give up features in their design to bring the project costs down and look to cut corners on building materials to help reduce the overall project cost. These value engineered tradeoffs are typically not seen until a building is occupied.

Life Safety – Making the Right Choice

The superiority of cast iron (CI) over polyvinyl chloride (PVC) piping in fire safety cannot be overstated. Many people who die in fires do not perish from flame or heat, but rather from the gases released during the heating and combustion of typical building materials or furnishings. Slowing or stopping the spread of these gases through aggressive firestopping is a proven life saver. Contractor and building owners today are concerned about liability.

Most experts agree that CI provides unsurpassed fire resistance. Cast iron does not burn, does not off-gas when heated to temperatures normally encountered in structure fires, it is easy to install, and has superior durability often out lasting the life of a building. This resistance to burning has the added benefit of requiring simple, low-cost firestopping between the annular space between the pipe and wall penetration. That is not the case with PVC piping where the initial cost savings are frequently offset by the added perfunctory material costs. Cast iron pipe and fittings are joined together with no-hub couplings consisting of neoprene gaskets and stainless steel shields and bands. These can be assembled or disassembled very easily.

Something else to consider if choosing PVC as it relates to fire wall penetrations. PVC is combustible and requires complex firestopping systems – each penetration between the pipe and wall infiltration must be sealed with an intumescent material. In the case of fire due to heat, PVC piping will melt away. Therefore, firestopping with intumescent product is needed to fill each and every void and penetration. This intumescent firestopping system is significantly more expensive than the simple and low-cost measures required for cast iron.

Sound Attenuation

Cast iron is often referred to as the “quiet pipetm” because of its superior noise suppression unlike PVC piping. Studies have shown CI to be a superior product in controlling noise due to its density. This makes cast iron ideal for condominiums, hotels, healthcare facilities and educational institutions. Unlike PVC, cast iron soil pipe effectively suppresses the sound of swooshing water cascading down from upstairs fixtures. This sound attenuation feature can be a major benefit in quality residential and commercial construction, where building owners and tenants understand the advantage of iron by the very first flush.

On the other hand, PVC used in drain and waste systems is noisy and annoying and often the cause of tenant frustration. If you’ve ever stayed in a hotel plumbed with PVC, you can often hear others showering and flushing toilets depriving guests from the well needed rest they desire. While plastic piping is an inexpensive material, it may not be the right product for every application. The problem with PVC pipe in drain and waste systems is that it produces a lot of noise due to the innate properties of low density plastic and the cementing of pipe and fittings together. To combat the noisy PVC piping system one solution is to wrap the PVC pipes with a good insulating material such as fiberglass or neoprene foam jacketing. The intrinsic properties of cast iron pipe along with the separation of the pipe and fittings by the use of a gasket or coupling is highly effective in reducing the likelihood of sound traveling through the system. Don’t get me wrong, there are special applications for PVC piping, but not in drain and waste applications.


Noise Level Chart

A noise level chart showing examples of sounds with dB levels ranging from 0 to 100 decibels.

0 = Healthy hearing threshold

30 = A voice whisper

25 = Cast iron vertical enclosed pipes (average)

33 = PVC vertical enclosed pipes (average)

50 = Light traffic or sound of a refrigerator

70 = A shower or dishwasher running

75 = A toilet flushing or vacuum cleaner

100 = Riding a motorcycle or operating a hand held drill


Summary of overall noise levels in dBA emitted by cast iron and PVC pipes while evacuating a 1.6 gallon water flush test. Significant findings that cast iron pipes are quieter than PVC whether or not the pipes are enclosed. This information is based on an independent research study by MJM Acoustical Consultants, Inc.

Listen Up – Noise Pollution is a Problem

Commercial building designers and engineers need to take note of the acoustical performance of the building project and be very cautious of the potentially negative effects of value engineering. Excessive noise from plumbing systems is typically unnoticed until the building is occupied, creating ongoing problems for the occupants. Sound attenuation is regularly value engineered out of jobs, often the result of product substitutions and misguided cost cutting measures. Beware of the unexpected consequences of value engineering.

The World Health Organization (WHO) has done extensive studies in healthcare facilities and has identified noise levels around rooms at night as disruptive to patients. This is especially true in hospitals with multiple levels. These types of structures also have additional noise pollution from waste water evacuation from toilets flushing, showers and storm drains. Excessive noise can lead to sleep disruption and increased levels of stress thus hindering the healing process sought in a hospital setting.

Studies have also concluded classroom noise interferes with the ability for a teacher to educate students effectively, and students to learn. Raising the voice level provides little compensation. ANSI Standard S 12.60-2002 Design Requirements and Guidelines for Schools recommend a maximum of 35 decibels for background noise. There is a direct link between the classroom acoustic environment and the scholastic achievement of students. The result of a US Government Accounting Office survey found that 28% of the nation’s schools reported “acoustics for noise control” as their top environmental problem. This suggests that the 28% figure from this survey may be a substantial understatement of the problem of acoustic barriers in schools since a background noise level of 50 db is 15 dB above the recommended limit included in a US standard for classroom acoustics.

The attributes of cast iron when it comes to sound attenuation cannot be overlooked. Due to its sound-deadening properties, cast iron inherently has a dense molecular structure and a natural heavy mass making it the quieter solution. According to a study by Polysonics Acoustical Engineers, cast iron is 750% more effective in silencing plumbing noise when compared to PVC. With CI, sound is effectively muffled rather than transmitted, as it is with PVC pipe. Noisy PVC piping can be masked by utilizing sound-deadening insulation that is carefully installed with neoprene foam jacketing or other insulation processes but there are again added costs to even come close to the quiet CI piping.



Friend, Foe or Both?

In conclusion, so do you know which product is better, cast iron or plastic? Both products have their advantages and disadvantages, though cast iron is more environmentally friendly than plastic as it is made from ~100% post-consumer scrap iron while on the other hand, thermoplastic piping is produced using petroleum derived materials. So we go back to which product is better. Well, the answer may be to consider using both together.  Plastic pipe is a great choice for the vent system since air doesn’t create vibrations and will be whisper quiet. While on the other hand using cast iron is an ideal solution for underground piping and vertical stacking of indoor pipes. This amalgamated method will benefit the occupants seeking a quiet and durable plumbing system that is a cost effective solution.

Word to the wise, consider the added costs if you choose PVC as it will require more hangers, screws, fasteners, primer, glue, additional labor costs, inspections, neoprene foam jackets to deaden sound, or insulation to muffle the noisy pipes. These supplementary costs are often overlooked when value engineering a project and can cost just as much if not more than a cast iron DWV system.


About the Author:

Francesca Dunbar is the Director of Marketing for the McWane Plumbing Group Division. She can be reached by email at Francesca.Dunbar@McWanePlbGrp.com.


Quiet Pipe is a trademark of Cast Iron Soil Pipe Institute “CISPI”.


1.      The Impact of Classroom Acoustics on Scholastic Achievement by Louis C. Sutherland and David Lubman, 17th Meeting of the International Commission for Acoustics, Rome, Italy, Sept. 2-7, 2001

2.      Plumbing Engineer – Features: June 2012: Sound design in drain, waste and vent lines http://www.plumbingengineer.com/june_12/piping_feature.php

3.      Acoustic Control LLC http://www.acousticontrol.com/hospital-acoustics.html


by plumbing expert Rich Grimes What is the best domestic water piping system? Great question with no easy answer! It is truly a matter of preference and each system has its own inherent benefits. Let’s look at some of the more common materials that are used. Most products up to 2″ size are Copper Tube Read more

by plumbing expert Rich Grimes

What is the best domestic water piping system? Great question with no easy answer! It is truly a matter of preference and each system has its own inherent benefits. Let’s look at some of the more common materials that are used. Most products up to 2″ size are Copper Tube Size (CTS) but alternative methods can be Iron Pipe Size (IPS). The key is that products must be NSF-61 listed for potable water.

COPPER is one of the oldest and most reliable methods for domestic water supplies. It has become an expensive metal over time so that opens the door for alternative piping systems. It has various benefits such as strength, corrosion and temperature resistance, longevity and its natural ability to inhibit bacterial growth. It uses full-flow fittings (tube fits inside of fitting) that are typically soldered connections.

CPVC is another CTS piping material that is often used for domestic water. It is a harder version of PVC that can withstand temperatures up to 180F. It employs a full-flow fitting that is usually socket-welded with solvent-cement. It is non-metallic so it can answer some issues that may arise with copper (dielectric corrosion, etc.) but it is a polymer that can degrade when exposed to petroleum and other chemical products. While it is mostly sold up to 2″ size in CTS, it also is sold as a Schedule 40 or 80 IPS potable water distribution system.

PEX is another polymer that is rated for domestic potable water. It is also CTS size tubing with an internal fitting. It uses a crimp-ring or clamp around the tubing and fitting to create a joint. Crimp and clamp tools are an integral part of the system for making a watertight connection. PEX is a flexible, labor-saving product that is produced in long coils. Long runs can be accomplished with fewer fittings or no fittings under slab.

There are several other polymers that have a NSF-61 rating, typically in IPS and used on domestic water lines over 2″ size. These are competing with large diameter metal piping systems for CW and HW mains of copper or SS.

One variable that must considered is the fittings to be used and the joining method. Today there are a variety of specialty fittings that can greatly reduce installation time and labor. While these fittings and joining methods may have a higher fitting cost, they can ultimately save money when considering the total installed cost. Press fittings have become popular because they greatly reduce labor and allow for a viable copper joint. Solvent welded CPVC can save labor over a soldered copper connection but there are solvent cement costs and joint curing times that must be considered. PEX fittings cost more that CPVC fittings but their clamping methods reduce labor and there is no waiting for curing. A mechanically-extracted tee on copper can eliminate most fitting costs and greatly reduce labor, but they require brazed joints and the cost of the tool system comes into play. Push-joint fittings eliminate tool costs, soldering or solvent-welding, down time, and labor but the fitting cost is higher…

It is probably best to look at items like project location, type of service, local environment, operating temperatures, ambient temperatures, tubing heat transfer, etc. to select the right piping or tubing for a project. Most contractors will utilize several if not all of these methods in their business, but typically standardize on a preferred pipe and fitting method. There is no single piping system that can meet every need and each system has its own benefits and best application. As well, each system is not bulletproof and can be susceptible to the surrounding environment, chemicals or various stresses that can cause a failure. Most products today have very high pressure ratings and it is proven that most piping failures are due to improper preparation and installation. If the manufacturer’s instructions are followed, any of these piping methods can provide a good domestic water distribution system that will last for years and years.

Choosing between High Mass or Low Mass boilers By Jack Daniels There has been much discussion on low and high mass boilers as of late. With high mass boilers now being available in highly efficient modulating and condensing configurations only adds more wrenches to that discussion.  The decision of what boiler to use is often Read more

Choosing between High Mass or Low Mass boilers

By Jack Daniels

There has been much discussion on low and high mass boilers as of late. With high mass boilers now being available in highly efficient modulating and condensing configurations only adds more wrenches to that discussion.  The decision of what boiler to use is often made in the boiler room. Today, let’s discuss the real basis on how to choose what boiler is right for you. Wise contractors know the system will tell you what boiler is best.

Taking a look at how the ideal hydronic system should operate is as simple as considering the idea that what is produced is used.  In other words, if we can achieve equilibrium and have the boiler start up in the fall and not shut down until the spring then we will be as efficient as the boiler’s ratings. As we all know, this is not always possible, heck, it is almost never achieved, thus the need for options in the configuration or mass of the boiler.

Suppose we have all of the proper elements of a hydronic system in their proper locales. The heat source (boiler), circulator, expansion tank, make up water, and heat emitters all have their own temperature and flow requirements. The objective is to achieve a reliable, inexpensive, comfortable, and over all efficient system. Failure to look at all aspects of the system will ultimately add to costs (initial and ongoing), as well as under heating, overheating, wasted energy, and most importantly, a disappointed customer.

First, let’s look at the low mass boilers. A few of the obvious benefits include low cost, high efficiency, and space saving. Another benefit to the low mass boiler is recovery time. A low mass boiler will come up to temperature very quickly as it does not have a lot of water to heat. This is ideal in applications that handle heating and domestic hot water needs. So, if I have a 2,500 square foot house that has one zone of in-floor heat the boiler can go from 120 degrees for the heating of the floor to 180 degrees for heating an indirect water tank very quickly.  Sweet! End of discussion. No need for high mass boilers.

What?! Your customer wants the bedrooms a tad cooler than the living spaces and wants to have the master bath warmer than the rest of the house? This creates the need for micro zones.  Now we have created a zone that can only “use” 6,000 BTU’s. Our low mass boiler can only modulate down to 19,000 BTU’s. We are producing more than we can use. Houston we have a problem. The boiler is going to take the water for the small zone to temperature very quickly (which is one of the advantages of a low mass boiler) and be forced to shut down.  The small zone, however, is still calling for heat so the boiler has to fire again and again as it takes the water for that small zone up to temperature very quickly and shuts down.  Repeat. Repeat. Repeat. Considering that each time a boiler fires it takes a short amount of time for the flame to stabilize and be most efficient in addition to stressing the components of the boiler, short-cycling will lead to a very unhappy customer.

So the answer here is to use a high mass boiler.  Awesome! Always use a high mass boiler when micro-zoning. End of discussion.  But now we have to keep all of that mass up to 180 degrees even in the summertime to produce the domestic hot water in addition to needing a mixing valve for the central heating. Though standby losses have been greatly reduced, they still exist. This is a system that should have mass added to the central heating side but not to the domestic water side.  See our last article in Wisconsin perspectives titled, “Ailing hydronic systems: Is there a doctor in the house?”  As you’ll recall, in that article we discussed buffer tanks in detail.

So if we do not have a domestic load in the aforementioned scenario should we use a high mass boiler? This author says yes. It is the best of all worlds. It can take advantage of outdoor reset and handle the micro zones with the energy stored in the higher mass.

Now, let’s take a look at high mass modulating and condensing boilers. We are no longer restricted to using cast iron behemoths that are not very efficient.  Manufacturers have recently introduced very efficient boilers that have the mass or storage needed for the micro zoned applications.  Other advantages of high mass boilers include lower pressure drop, less maintenance, and ease of installation as there is no need for primary secondary piping.

I would also use high mass boilers in any system that you would suspect debris. Retrofit applications replacing cast iron boilers are an ideal place for a high mass boiler. Gone are the worries about plugged exchangers, water treatments, and endless flushing. Let’s not forget high mass boilers were first then the low mass boilers came on the market as higher efficiency options.  Now, with high mass boilers being as efficient as their low mass counterparts, I view them as another option in the arsenal of comfortable, money saving options heating professionals can offer their customer

So the answer about whether to use high mass or low mass boilers stays the same; it depends.

For information from the author, contact Gregory “Jack” Daniels, Hot Water Products, Inc, (877) 377-0011, HotWaterProducts.com

Success – by Jim Hinshaw Just had a conversation with a client: what are the top three things that are standing in our way to improving profits this year?  I said, my view from 30,000 feet, here are three that I see.  Not enough leads, close rate too low on the few leads we have Read more

Success – by Jim Hinshaw

Just had a conversation with a client: what are the top three things that are standing in our way to improving profits this year?  I said, my view from 30,000 feet, here are three that I see.  Not enough leads, close rate too low on the few leads we have, and profits are lower on the few we do sell.  Sort of connected, one leads to the next in some ways.  Take the not enough leads opportunity: when the number of leads drops off, we look at our numbers, realize the bank wants the mortgage money even if the weather was beautiful, sale or no sale.  So we lower our prices, but turns out the competition is doing the same thing.  And even if we do sell one, it is at lower efficiency and/or price point than we hoped for, so the profits are not there.  How do we fix that?

First of all, don’t depend on the weather, the economy, or some government tax credit  to drive your business.  It will disappoint you.   How do we make the phone ring?  Simple, by picking it up and dialing it.  Yes, calling your customers.  Go ahead, tell me you can’t, against the law, all that sort of stuff.  Not if they are already clients.  So call your customers who have done business with you in the past, offer them a discounted tune-up, a safety inspection, or free analysis of their water in the home.  People are not doing maintenance as much as they used to in this economy, but they will spend money on three things: health, safety, economy.   They will not call in, you have to initiate the call, make the offer a decent one that gives them some assurance they will get a positive result (maybe a money back guarantee?), make it a positive thing.

Two other positive outcomes from calling out to your customer base.  The replacement job is not on the street.  You created the opportunity.  The customer who has used you in the past trusts you; you have become the trusted advisor.

Now, how do you build your customer base.  One way is to join a networking group.  Like BNI.  Business Network International.  Go to bni.com.  You can find a chapter near you, and search for chapter that is looking for your trade.  They only allow one company from each trade, if you are the plumbing company, there is not another one.  Cost is about $400 per year; a couple of service calls will repay that investment.  Typically you can sit in a couple of meetings without joining, see if the magic is there.  If not, try another group.  Find one that meets in the morning, with over 20 members.  Less than that, they are not an a fully functioning group, may be a while before they get traction.  Usually the real estate, insurance, and lawyer groups meet at noon for lunch.  Our best bet is in the morning meetings with the painter, roofer, floor covering company, ones that are getting engaged with remodeling projects.  So if you cannot make that happen, form your own networking group.  Meet for coffee once a month with a roofer, pest control company, alarm company, companies you trust and would like to refer people to.  See how their business is going, and something neat will happen.  They will actually help grow your business.  Have a formal program in place where your company knows who to refer a roofing job to.  Don’t ask or expect a referral fee, instead let them know you want reciprocity.

One creative idea that I heard recently, a heating/air conditioning contractor worked with a pest control company to build his business.  When someone signed up for a monthly pest control service, they also got a heating/air conditioning maintenance at no cost.  What does it cost to add a new customer?  Adams Hudson will tell you it can be as much as $400 to bring them into the boat.  So spend less than $100 in labor, pick up a new customer, which is also a positive thing for the pest control company.   That is the sort of thing you can test on a small scale, grow it if it works.

So when you begin to look at projects that are referral based, or your own customer base, the last two items are taken care of.  You close more, at higher prices.  You are a trusted advisor, and the customer will open up with their real concerns, and you will sell more of the cutting edge products, higher efficiency, higher priced.  Instead of having to beat the other guys price.  When you tell the customer the price is built on what they said they wanted, they realize it is not your fault, they actually asked for that investment number.

Another item that will glue the customer to your company is your maintenance agreement program.  I talk to contractors all over the nation, just spent some time with a company that has been in business since the 50s.  Over 60 years.  I asked them if they had a maintenance agreement program, they said yes they did.  When I asked how many agreements they had, it got real quiet.  Finally went to the service dispatcher, she said they had almost 300 in effect.  The owner challenged her, said it had to be more, but it wasn’t.  So they had about 5 per year in business.  Not good.  No matter if you have been in business 5 months or 5 years, start today to sell maintenance agreements.  Set up a goal to add 100 or 500 this year, break it down to so many a month, per tech, per day, make it easy to track.  Then track it.  Share the results weekly on a chart, get the entire company involved.  Have a weekly award for most sold, greatest improved, largest dollars, that sort of thing.  Your maintenance agreement can be on HVAC, or Plumbing, or both.  Why not combine them into one great maintenance program, where you drain the water heater each year, check all the hose bibs, that sort of thing.

If you need help putting that program together, let me know, have done that many times.  And thanks for listening, next month have a great testimony from a client who used some sales techniques to land a couple of interesting jobs totaling over $500,000.  Yep, half a million, two jobs.  From a company that does a lot of residential, and one of these was a public bid that had to get three prices.  All by listening and taking action, not doing what the other guys were doing.

Oh, thanks also from those who bought my book, had some great sales last month, just got a check from PayPal, that is a good thing!