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One of the most common home inspection concerns for home buyers is ceiling stains. While it’s not always possible to determine exactly what caused a ceiling stain, the location of the stain will often give away what caused the stain. For example, the photos below show an improperly flashed chimney at a home in Saint Paul, and a corresponding stain at the ceiling in the bedroom directly below.

The most obvious concern with ceiling stains is roof leakage. When a home inspector finds a suspicious ceiling stain, they’ll typically use a moisture meter to help determine whether it’s an active leak or not.  The video clip below shows me using the non-invasive feature of a moisture meter to confirm that the ceiling stain shown above was caused by active leaking.

If a stain is wet, most home inspectors will be able to trace down the source of the moisture and recommend a repair. When a stain is dry, it means the cause of the staining has been corrected or the conditions that caused the staining to occur are no longer present. In these cases, it’s a good idea to ask the seller about the history of the staining; specifically, what caused the staining and has the cause of the staining been corrected?

There are a number of other types of ceiling stains that are quite easily identified.

Stains below bathroom exhaust fans

This is one of the most common ceiling stains you’ll find in Minnesota, and it’s caused by condensation. When a bathroom exhaust fan is connected to an un-insulated duct that runs through the attic space and doesn't make an airtight connection to a proper roof cap, the moisture that’s supposed to exhaust to the exterior is going to condense like crazy.

I know I've shared this photo below, but I have to share it again. The duct pictured below was completely filled with condensate in the attic. I set my flashlight behind the duct to take this photo showing how full of water it was.

As all of this moisture condenses inside the duct, it eventually drains down to the bottom of the duct and then leaks on the ceiling next to the fan. Boom. Ceiling stain.

The fix for this condition is to make sure the duct for the bathroom exhaust fan is properly installed; this means an insulated duct, a short run, and airtight connections.

Stains at outside wall/ceiling corners

When stains appear at the ceilings along outside walls at the corners, it’s typically the result of ice dam leakage. If the insulation in the attic is insufficient and there are attic air leaks, it’s very likely that ice dams caused the leaking. In these cases, our recommendation is often to have the attic air leaks sealed and more insulation added to the attic. This is typically what it takes to prevent roof leakage from ice dams.

Random ceiling stains, no roof leaks

Condensation that occurs in the attic is a common cause of random ceiling stains. When enough frost builds up in the attic, it can leave enough water when it melts to create stains in a bunch of random places.

To help determine if an attic experiences condensation problems, take a close look at the nail heads; if they’re rusty and there are stains on the roof sheathing around nail heads, it’s a condensation issue. The fix for this is to seal attic air leaks and reduce indoor humidity levels.

Stains below plumbing fixtures or radiators

These are both pretty obvious, right? When a home inspector finds a stain below a plumbing fixture, the next step is to use a moisture meter to see if there is active leaking. If the stain is dry, the plumbing fixture above should be thoroughly tested, and then the stain should be checked again.

This list makes up the vast majority of ceiling stains that we encounter during home inspections.  Stains on ceilings are definitely worth further investigation, but most of the time they’re only indicators of past leaks, many of which occured a long time ago.  Why?  Because active leaks will quickly destroy ceilings and they're extremely difficult to hide.

Author: Reuben Saltzman, Structure Tech Home Inspections

Before turning on your air conditioner for the first time this year, there are three basic maintenance items to check on; the condensate line, the air filter, and the condensing coil.  According to Mark Jerde of RightMark, these three items make up a large portion of easily preventable equipment failures.

The Condensate Line

In Minnesota, about 99.2% of single family homes with AC have a split system.  This consists of a big box that sits on top of the furnace called an evaporator coil, which is connected to another box at the exterior that contains the compressor and condensing coil.  If you're curious about how this system works, head on over to HowStuffWorks; they have some nice descriptions and illustrations.

An air conditioner 'conditions' the air by removing heat and moisture.  As warm, moist air gets passed over the evaporator coil (the thing that sits above the furnace or air handler), moisture condenses on the cold tubing.  This condensate drains down to a pan where it gets directed out.

Condensate needs to be directed to an appropriate location, which is typically a nearby floor drain. The drain material must consist of cast iron, galvanized steel, copper, PEX, polybutylene, polyethylene, ABS, CPVC, or PVC pipe or tubing.  The drain must also have an internal diameter of at least 3/4".

When improper materials are used, the drain is undersized, or when the drain needs to wrap all over the basement to get to a floor drain, the condensate drain has an increased potential to get blocked up. If the condensate drain consists of a garden hose or clear plastic tubing, replace it. This will help to prevent a blocked condensate drain, which will help prevent unwanted leakage at the evaporator coil.

Before running your air conditioner for the first time during the summer, make sure the condensate drain is directed to an appropriate location.  When the AC condensate drain needs to run across the floor of a room, people often coil the drain up so it's not in the way when the AC isn't being used.

The Air Filter

The air filter, also known as the furnace filter, needs to be replaced regularly.  Usually every one to three months will do, depending on the type of filter that's installed.  While most homeowners know about changing the filter during the winter, this still needs to happen during the summer when the AC is running.

If the home has a high-velocity system with an air handler in the attic, the filter will usually be located at the ceiling in an upper level hallway.

Restricted air flow = reduced efficiency.

The Condensing Coil

This is the one that gets forgotten about the most.  The compressor and condensing coil are the parts that sit outside the home, preferably in some out-of-the-way part of the yard.  To help dissipate the heat that gets removed from the home, a big fan pulls outdoor air over the condensing coils.

For the condensing coil to work properly, it needs plenty of air flow.  This means no trellis attached to it, no ivy, no plants, no walls, no boxes, and so on. Clearance requirements will vary from manufacturer to manufacturer, but a good rule of thumb is 24" of clear space.  Keep vegetation trimmed away.

Condensing coils also need to be cleaned regularly. When they're covered with dirt, dust, grass clippings, dryer lint, cottonwood seeds and other outdoor stuff, air flow can be severely hampered.  Take the time to inspect all sides of the unit and clean the coils off if necessary.  This can usually be done by spraying the unit down with a garden hose.  Don't try a pressure washer; the fins will bend very easily.

If the unit has protective grills that prevent access to the coils, the grills will need to be removed first.  At that point, a little bit of dismantling is involved, and some homeowners might prefer to contact an HVAC tech to do the work.

Author: Reuben Saltzman, Structure Tech Home Inspections

This is a follow-up to last week's post, which gave a home inspection checklist for the exterior of homes.  The goal of this checklist is to give potential home buyers a 'heads-up' for some potentially larger defects.  This is obviously not a complete or technical list, but it covers a lot of potential problems.

Foundation Problems

Look for cracks in the foundation walls.  Generally speaking, cracks larger than 1/4" in concrete block walls and cracks larger than 1/8" in poured concrete walls are reason for concern.

Cracks that are large enough to put your hand through shouldn't be cause for concern.  They're cause for repair.

Cracks that have been patched and have opened up again are reason for concern, as they typically indicate ongoing movement.  Horizontal cracks are more concerning than vertical cracks.

Offsets in the foundation walls are cause for concern as well.  The house shown below ended up being demolished.

Wet Finished Basements

It's usually quite easy to figure out if a finished basement has moisture problems if you're willing to do just a little bit of digging.  Walk around the exterior of the home first, and look for any areas without good water management; for the most part, this means negative grade and missing downspout extensions.  When downspouts discharge next to the house, there's a good chance that there will be a water intrusion issue at about the same place inside the basement.

Basement water intrusion staining always starts at the base of the foundation walls.  Pay special attention to inside corners for signs of water intrusion.  Loose for stains at the baseboard trim, and stained or patched wall areas.  Look behind furniture, and look underneath carpet if possible.

The photos below shows stained wood paneling and black, wet carpet tack strips in the same place.

The photos below, from the same house, show black staining (mold?) at the drywall in one of the inside corners, as well as staining at the baseboard trim.

If there are in-floor ducts, try to look inside the ducts at every floor register.  If water has entered this ductwork, it's a serious problem.

Plumbing - Galvanized Steel Pipes

Galvanized steel water pipes were used on older houses up until about 1950.  The problem with galvanized pipes is that they rust on the inside, making the pipe diameter smaller and smaller over time.  This leads to less and less water flow at the plumbing fixtures.  Galvanized pipes are also more prone to leakage, typically at the joints.

To test water flow at older houses, turn on the laundry sink faucet all the way and then check water flow at the other plumbing fixtures throughout the house. On houses with galvanized pipes, we'll frequently find no water flow at the second floor plumbing fixtures when performing this test.  Once it gets to that point, it's time to think about new pipes.

The photo below shows a first floor kitchen sink faucet turned on all the way; if you look carefully, you can see a few water droplets in the air.  The repair for this condition is to have a plumber replace the old galvanized steel pipes.

The pipe coming from the street to the house is called the supply pipe; when this pipe is galvanized, there's a good chance that water flow throughout the house will be minimal.  The fix for this is expensive; it means digging up the yard and replacing the pipe out to the street.

On older houses, check below the water meter in the basement to verify the supply pipe is something other than galvanized steel.  The photo below shows an example of a galvanized water supply pipe.

As with galvanized steel water pipes, galvanized steel drain pipes also rust on the inside.  This accumulation of rust reduces the pipe diameter and can lead to clogged drains and leaks.

Galvanized steel plumbing vents also rust out; sometimes they may completely rust through and allow sewer gas in to the home, but the vents are typically concealed.

The eventual fix for this is replacement of the old steel drains and vents with new ABS or PVC pipes.  The first drain to get clogged will always be the kitchen sink drain.  Run water down the kitchen sink for about ten minutes to make sure it drains properly.

Neglected Furnaces / Boilers

Watch out for excessive rust, debris, and especially black soot or scorching at the furnace or boiler.  These typically indicate then need for service or replacement.

Electric Hazards

FPE Stab-Lok electric panels are a latent fire hazard.  These panels can be easily identified by a label on the panel that says "Stab-Lok".  We always recommend replacement of these panels.

In houses built from 1965-1974, look for aluminum wiring, or more specifically, aluminum branch circuit conductors.  These are a larger concern that can involve expensive repairs.  It's not always possible to identify aluminum wiring without opening the electric panel, but if aluminum conductors are used with NM cables (aka 'Romex'), it will say "aluminum" right on the cable sheathing.  Look for this in the garage or basement.

Fuse panels under 100 amps are typically inadequate for today's houses.

To help determine the size of the electric service, look on the door of the electric panel.  Most old fuse panels will either be 60 amp or 100 amp.

Knob & Tube wiring is an obsolete two-wire system typically found in pre-1930's homes, and is easily identified by the porcelain knobs & tubes that are used to hold and protect the wires.    When present, knob & tube wires will usually be visible in attics and unfinished basements. The photo below shows an example of exposed knob & tube wiring at the ceiling in a basement.

At best, the remaining knob and tube wiring is in good condition and most of it has been replaced.  Be aware, however, that many home insurance companies charge a premium or refuse to insure homes with knob & tube wiring, even if it's still in pristine condition.

At worst, the knob & tube wiring has been exposed to high temperatures for long periods of time, causing the insulation on the wires to fall apart, leaving exposed conductors that create a shock and fire hazard. Examples of hazardous knob & tube wires are shown below.  Yes, these wires were live at the time of the inspection.

Interior Stains

Stains at the base of patio doors typically indicates water intrusion and rot.  Step on the floor next to patio doors to make sure the wood is solid.  The photo below shows major rotting at the floor by the patio door.

Water stains on windows are usually caused by condensation, which isn't a major concern, but stains that are caused by exterior water intrusion are a larger concern.  To help determine the difference, click this link on window stains.  The photo below comes from that post, showing an example of window staining caused by water leakage from the exterior.

Hopefully these items will give potential home buyers a good starting point.  As mentioned last week, here's a one-page Home Inspection Checklist in pdf format that may be helpful.

Author: Reuben Saltzman, Structure Tech Home Inspections

For home buyers interested in conducting their own home inspection, here's a list of larger items to look out for while viewing houses.  This is a cursory overview of some of the larger problems that are frequently identified during home inspections.  Of course, this is no substitute for a professional home inspection, but it's a great start.

Roof Problems

While many roof problems can only be identified by actually walking the roof or leaning a ladder up against the eaves, some defects can be easily seen from the ground.  Be sure to view all sides of the roof.  In older neighborhoods with tall houses that are close to each other, it may be necessary to walk a fair distance down an alley to get a good look at the roof.

Look for any irregularities with the roof: shingles that look curled from the ground indicate an old roof.  This type of curling almost always happens on the south side first, so pay special attention to that side.  The photos below show examples of some particularly nasty roofs.

Look out for cracks in shingles as well.  These typically won't be visible on second story roofs, but it's sometimes possible to spot these on single-story roofs.

Mis-matched or patched shingles, missing shingles, and shingles sliding out of place typically indicates an improper installation.  The photo below shows a horrible patch job. A 'new' roof doesn't mean a 'good' roof.

Always look for loose shingles in valleys.

A large section of the roof below had been patched. Why was the roof patched to begin with? A patched roof is often the result of an improper installation that has led to shingles coming loose.

Shingles without neat rows may have been installed that way, but it may also mean that shingles are beginning to slide down.  Closer inspection of this roof revealed that the shingles were improperly nailed, causing the shingles to slide down.

Here's a more extreme example of sliding shingles.

Don't forget to view all sides of the roof.  This next roof was too high to be safely inspected with a 28' extension ladder, but a walk down the alley revealed considerable, obvious damage.

Chimney Problems

Chimney repairs can be another large expense.  When buying an older house with a masonry chimney, take a close look at it.  Missing mortar between the bricks typically won't be a major repair, but missing bricks and large cracks in the walls can sometimes mean the upper portion of the chimney needs to be re-built.

As with roofs, be sure to look at every side of every chimney.  The chimney shown below had been redone to look good from the street, but didn't look so great from the back yard.

Problems with the chimney flashing, crown, and interior flues are difficult to identify from the ground.

Siding

Hardboard siding begins to swell and then literally fall apart when it rots. Deteriorated hardboard siding is usually quite easy for anyone to spot. Check the north sides, areas not protected by soffits (overhangs), and the areas closest to the ground first; these will be the first areas to rot. If unsure about an area, push on it with your finger, but not too hard.  When hardboard siding is badly rotted, it gets mushy.

Defects with newer stucco siding are difficult to identify from the exterior, but stains below windows are an obvious warning sign that there may be hidden damage.

Problems with others types of siding usually aren't as easy to spot without a trained eye.

Windows

Rotted wood windows that have been patched may look fine from a distance, but it's usually easy to spot damaged areas when up close.  Give the windows a little poke with your finger when rot is suspected.  Sometimes the patchwork will be paper-thin, so don't poke too hard.

Aluminum clad wood windows can completely rot apart on the inside, yet leave no visible evidence at the exterior.  These windows can be pushed on or squeezed to help determine if there is internal rotting.  The windows that will rot first are the ones that aren't protected by soffits (overhangs).

In the photo below, we pulled some of the cladding back to show severely rotted wood inside the sash.

Cranking windows open and looking at them from underneath can sometimes reveal water damage.

Decks

Always take a look underneath decks.  Sometimes decks will have a fresh coat of paint that conceals severe rotting, which may be quite visible from below.

Also, take a step back from the deck and look for sagging, which may indicate a structural problem with the construction of the deck.  The deck shown below had a very noticeable sag in the middle which wasn't obvious from up close.

Click this link for more info on deck inspections.

Water Management

This one is huge.  Make sure water is properly directed away from the house.  Look for proper gutters, downspouts, and downspout extensions.  They're not required, but they certainly help.  Also, check to make sure the earth slopes away from the house.  Water draining toward a house can lead to big water problems in the basement or crawl space, as well as foundation problems.

Look at roof lines as well; if water gets concentrated against the house, the potential for water intrusion goes up.  The photo below shows a good example of several roof surfaces concentrating water in to a small area right up against the house.

Next week I'll have a home inspection checklist for the interior, along with a one-page pdf checklist of all the interior and exterior items.

Author: Reuben Saltzman, Structure Tech Home Inspections

Many older houses in Minneapolis and Saint Paul have an old style of plumbing trap called a drum trap, which is no longer allowed in Minnesota except in special circumstances.  The photo below shows an example of a relatively small drum trap found below the bath tub at a recent home inspection in Hopkins.

Drum traps come in all different types of shapes, sizes, and configurations.  The crude diagrams below show a few examples of different types of drum traps I've come across, as well as one type of setup that wouldn't create a water seal trap, shown at the bottom right.

As mentioned in previous posts, the purpose of a plumbing trap is to prevent sewer gases from coming in to a building.  A drum trap does the same thing, but instead of just having a dip in the pipe to create a P-trap, a drum trap consists of an enlarged 'vessle'  that holds a large volume of water.  In the Twin Cities, drum traps were commonly used at bath tubs and occasionally at laundry sinks.

Why they used to be popular

In my posts about s-traps and plumbing vents, I explained how proper plumbing vents prevent water from getting siphoned out of traps and why it matters.  Water can be siphoned out of a drum trap in the same way it can be siphoned out of a p-trap or s-trap, but drum traps hold so much water that it's pretty much impossible to have enough water siphon out to allow sewer gas in to the home.

Drum traps were also supposed to be easier to open up for cleaning and retrieving lost items, but it didn't always work that way.  I'll come back to this.

Why they're no longer allowed*

One of the basic plumbing principals of the Minnesota State Plumbing Code  (4715.0200, "s") says that "Each fixture shall be provided with a separate, accessible, self-scouring, reliable trap placed as near to the fixture as possible."  If you take apart any properly installed p-trap, you'll probably find that it's nice and clean inside; this is because it's self-scouring.  The water drains through the trap in such a manner as to pull solid materials out of the trap along with the water.

The main problem with drum traps is that they're not self-scouring.  A drum trap holds so much water that the water and solids coming in to the trap will not be pulled directly through, which can allow for the accumulation of solids in the bottom of the trap.  This makes drum traps more prone to getting clogged.

Another problem with drum traps is that they can be difficult to clean out.  Most drum traps have a removable cover, but drum traps are usually located right below the floor, making the lid extremely difficult to access without cutting out the floor.  At my last house in Minneapolis, there was a removable panel in the floor created just for accessing the drum trap.

Even when the cover is accessible, it can be difficult or impossible to remove the cover because the threads are rusted shut.  One Minneapolis home-improvement blogger recently wrote about how he was able to saw the top of his drum trap off, and then covered it over with a rubber test cap.  While the test cap is only supposed to be used temporarily, I suppose I wouldn't hesitate to do the same thing if I had a problematic drum trap.

When the cover for a drum trap is accessible and easy to remove, it's important to make sure that it makes a tight seal. It has the potential to allow sewer gas in to the home or leak if not sealed properly.

What to do about them

If you have an old drum trap in your house or you're buying an old house with a drum trap, there's no need to get whipped up.  Drum traps usually work just fine, but they're more prone to getting clogged, and can be difficult to service.     Wait until a plumber is out doing other work to have your drum trap replaced.

On a personal note, I had a drum trap at my last house in Minneapolis.  It clogged shortly after I moved in, so I removed the cover and cleaned it out.  I put the cover back on, and never had a problem with it for the next seven years that I lived there.  It was installed in such a way that replacing it would have required making a nasty hole in one of my floor joists, so I just left it alone.

*The exception

Section 4715.0960 of the Minnesota State Plumbing Code says that "Drum traps shall be installed only when permitted by the administrative authority for special conditions (laboratory tables, dental chairs, etc.). "  Drum traps are allowed in these locations because they're not self-scouring.  If someone's gold filling falls down the drain, a drum trap will allow it to just sit in the bottom for retrieval.

A few photos, just for fun

The photo below shows a crown-vented lead drum trap with the cleanout at the bottom.  The bath tub drain was also leaking.

This next one shows a relatively new PVC drum trap.

The drum trap shown below leaked profusely when we filled the bath tub with water and then drained it.

Here's a drum trap at a laundry sink.

The drum trap at this next laundry sink had a severely corroded cap.

This next one shows a drum trap installed on its side, along with a bunch of those rubber clamp connectors that aren't supposed to be used.

Below is one of my favorite photos of all time, which I've shared before.  This drum trap had probably rusted apart or someone had to cut the bottom off to clean it out, so MacGyver  fixed it with the bottom of a coffee can, glue, tape, and string.  Spray painting the bottom red was also a nice touch.

Author: Reuben Saltzman, Structure Tech Home Inspections