Things you should know about your furnace

    In the most recent monthly meeting of our Midwest Association of Home Inspection (MAHI) the guest speaker was Peter Fiedler of Sabre Plumbing, Heating & Air Conditioning. He conveyed  some very enlightening information about the standard forced air furnace systems and what causes some to fail prematurely. Here is your basic forced air furnace system: 

    forced air furnace system

    At its most basic operation it pulls air from the return duct, across the filter element, and powered by the blower, sends the air across the heat exchanger and up the supply duct to the home. 

    There is a fair amount of engineering mathamatics that goes into calculation the size of the a furnace, but it comes down to the amount of (cfm) cubit feet per minute the blower can send across the heat exchanger. That number, say 400 cfm for an average sized furnace, is needed to not only extract heat from the heat exchanger, but to actually keep the heat exchanger cool. Absent that cooling the heat exchanger will fail prematurely. 

    Assuming the furnace is sized properly, the biggest killer is a dirty filter. Now you know why. A heat exchanger that is starved for cooling, overheats, and prematurely wears out. Another culprit is return air registers that are blocked or sealed off. The systems are calculated with "X" number of return registers bringing air back to the furnace via the return duct. When that air flow is blocked or diminshed the heat exchanger suffers.

    There are two quick field test that can be done to access the relative health of a forced air furnace. 

    1. With the unit running, lift off the filter cover. If you discover a substantial vacuum when pulling up the cover, then the furnace is/has been starved for return air. Consider crytically the health of the heat exchanger. 
    2. With the unit shut down, remove the filter element. If this is changed regularly there will be a minimal about of debris on the element. If it is filthy, bowed or ill-fitting, it will have been busy reducing the lifespan of the heat exchanger. 

    A basic furnace filter that fits well in the filter bay, has a sheet metal cover, and is changed regularly is the cheapest insurance you can buy for your forced air furnace. 


    Why sub-panel bonding is important

    In the service panel (main breaker box) one will often see GROUNDED CONDUCTORS (i.e. neutral or white wires) attached to the same bus bar as EQUIPMENT GROUND CONDUCTORS (i.e. bare copper or green wires).


    Main service panel details


    This is permitted because the service panel is the entry point for electricity coming from the transformer outside into the home. The service panel can be seen as the starting line and the finish line for current flow in the home. 


    What we want is for current to leave the Service Panel’s hot leg (i.e., the breaker), to travel to and through the load (your light bulb), and to make its way back via the neutral, without having the option of taking any other path.


    If we connect the (white wires) and the (bare copper)  together, anywhere downstream of the Service Panel (e.g., bonding them inside a sub-panel), then the current will have TWO paths to take: the (white wires) and the (bare copper). And it will take both paths. While  the (white wires) is out of reach of human hands; the (bare copper) is not.  The (bare copper) connects to external metal parts (i.e. a refrigerator's metal case). Therefore, if a human touches the metal parts, the current will have THREE paths back to its source: the (white wires), the (bare copper), and the human. And it will take all three paths.


    sub panel details



    Proper fastening wooden decks 

    Prior ot January 1 2004 fastening a pressure treated wooden deck to the side of a home was pretty straight forward. You still had to follow best building practices such as properly fastening and flashing of the ledgerboard, and using approved joist hanger and other hardware. But most important, the selection of fasteners was the same as it had always been. 

    Then came the change. Before 2004 the pressure treated wood used was CCA short for "Chromated Copper Arsenate" The Arsenic in the compound was leaching out and affecting the environment, so the composition was changed to ACQ or "Alkaline Copper Quatetnary". 

    This formula worked just fine against fungus and bugs, but it also reacted agressively with metal. No longer could a builder use the fasteners and hangers they had been using in the past. They had to change to the more expensive "Hot Dipped Galvanized" fasteners and hangers.

    Hot dipped galvanized

     Non approved fasteners simply desolved. 

    corrosion on deck screws

    For the most part deck builder have transitioned to the proper fasteners, and for economies of scale, manufacturer's mostly only supply hangers and hardware compatible with modern pressure treated wood. 

    The problem lies in that delicate transitionary period around January 2004. If you think back serveral years ago there was a rash of spectactular deck failures. Usually while supporting a party or wedding. The incompatibility between the agressive formula of the new ACQ and the old non galvanized fasteners took several years to come to fruition. When it did it was catastrophic. 

    deck collapse

    The upshot of this blog is. if you had your deck build during that dicy tranistionary time, inspect the underbelly of your deck for corrosion.

    corrosion of deck joist hangers

    That is why every fastener, joist hanger and metal tie gets inspected at Diamonds In The Rough Inspections. A buyer would expect no less. 



    Lead piping in the home

    On a recent inspection I came across some lead pipes. Since lead pipes and lead in the drinking water was in the Flint, Michigan news lately I thought i would dig into it a bit deeper. 

    Lead pipes found in homes come in two catagories, waste water pipes and fresh water supply pipes. They are easily identified by their bulcous connectors. 

    lead waste water pipes

    lead pipes water supply line

    Lead pipe used in waste water system



    lead waste water pipe cross section

    Lead pipes in the waste water lines pose little danger to homeowners. Lead pipes in the fresh water supply lines, however, does merit some concern. 

    Since the lead pipes found in the supply line of this home were on the "street side" of the water meter, it is a safe bet that lead pipes were used to connect the house to the city water main. 

    According to the CDC Lead pipes in good repair pose less of a danger than lead chips in paint. The EPA has set an action level of 15 parts per billion as a safe level. So, like radon levels in a home, a test must be conducted. 

    Contacting the city water board is the first course of action for spectific information on their lead pipes as well as recomendations for testing compainies. Quite often the city water boards will test your water for free. 

    If you have elevated levels of lead in your water you can mitigate the ill effects by simply running COLD water for 1-2 minutes if the water has rested in the pipes for 6 or more hours. It is recommended to use COLD water for cooking and drinking as hot water will tend to concentrate the contaminant. Showering with hot water has no ill effect. 

    Here are links to the CDC's take on lead


    As well as EPA's information


    A note on what happened in Flint, Michigan: lead pipes were used for years in Flint with little ill effect until the city managers decided, for financial reasons, to switch to a highly acidic water source. This new water reacted with the old lead piping and started to degrade the pipes, causing lead and other contaminants to leach into the drinking water.

    The moral here is: pay attention to any changes in your cities water supply.  


    Raising Cement Walkways

    In the past if you had a section of concrete walkway that was no longer level due to settlement of the underlying soil you had to resort to what was called mud jacking.

    Mud jacking consists of drilling an 1-1/2in hole or holes in the concrete and injecting liquid concrete into the holes under pressure. This lifts the concrete section up. There were a few problems with this procedure. While it would lift the concrete slab up to level the weight of the injected mixture was so heavy it compressed the underlying soil even further bringing the longevity of the repair into question.

    The new procedure is to inject poly-foam instead of a cement slurry. The biggest benefits are that it sets up very quickly, is very light weight, can be applied with remarkable precision and the entry hole is very small (5/8 in. vs 1-1/2 in).


    After either mud or poly jacking the access holes are capped with cement. The caps rarely match, so the smaller the hole the less noticeable. 


    As an ongoing commitment to excellence, we are members of MAHI and as such attend monthly continuing education seminars. These seminars are hosted by leaders in various trades (electricians, plumbers, structural engineers, etc.).

    The industry insights from these seminars serve to make us that much more useful and knowledgeable as Home Inspectors. As a bonus, often these same industry leading companies will off members of MAHI service discounts to pass on to their Home Inspection Clients. 

    Just one more reason to have your home inspected by Diamonds In The Rough Inspections !


    Hot water heaters and Legionaires' Disease

    Recent outbreaks of Legionairs' disease in the City of Hopkins has made me look into the relationship between the disease and domestic hot water heaters. 

    Legionairs' disease is a pulminary disease caused by asperating (breathing in) a certain bacteria. The bacteria grows in stagnant warm water. There is concern that it can grow in domestic hot water heaters that are set at a low setting. 

    Setting hot water heaters at a temperature high enough to destroy the organism (around 140F degrees), also sets up the potential for serious scaling in a domestic setting. 

     So there is the yin and yang of the thing.

    There are temperature regulating valves that can be added to the hot water heater. This allows the heater to be set at 140 degrees but tempering the scalding water prior to delivery to your fixtures. 

    It may also be worth inderstanding the risk of catching this disease. The Legionairs' disease bacteria is commonly present in the environment and most people have a natural resisance to it. Reported cases are sporatic. CDC and OSHA estimate 3% to 15% of the population are at risk. Not that great when you think of all the other things that can get you. 

    Need more info? Check out OSHA fact sheet. https://www.osha.gov/dts/osta/otm/legionnaires/faq.html

    But it is always  good to know where you stand . 



    Your air conditioner's outside condenser unit needs some love!

    One of the common defects I find on a home inspection is damage to the refrigerant lines that arry the coolant from the indoor air handler (furnace in the winter time) to the outdoor condenser unit (the big fan). There are two lines, a fat one (cold) and a skinny one (hot). When the A/C is running the air handler pumps hot coolant to the outdoor compressor where it is chilled down. Then it is pumped back inside to deliver its wonderful coolness to the air handler and in turn to you sitting on the couch. So the fat line off the compresser is insulated to keep all that cool goodness from excaping into the beastly hot out of doors. Often the insulatior. n takes a beating from weed wachers, rodent, kids retrieving an errant ball, or simply worn out by UV rays. Check out my video for a very simply repair.


    Proper Flashing

    Here his a great example of proper flashing at the chimney/cricket location. Proper flashing is "let into" the chimney. In other words a groove is cut in the brickwork and the flashing is folded 90 degrees and tucked into the cut. It is held in place with mortar. 60 years old and still totally waterproof. 



    White glove, er...White bootie service

    Every house I inspect get a pair of these babies on my boots. No harm, no foul!



    New truck graphics 

    Installed today from Sign-a rama. Now I am official 

    Truck graphics

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