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
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.
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.
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.

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.
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.
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.
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.
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 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.
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.
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.
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.
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
One of the most common Truth-in-Housing repair items is an unfilled opening in an electrical box or panelboard. If you walk through the garage or basement of just about any old Minneapolis or Saint Paul home, you'll probably find a few of these.
The national electric code says that unused openings in such equipment need to be closed. Covering these openings helps to prevent accidental shocks (think of kids), helps to prevent hot sparks from escaping if something goes wrong inside the enclosure, and helps to prevent pests from entering. It happens.
First, determine the size of the missing knockout hole and subtract 3/8" to figure out what size knockout plug you'll need. For example, if you have a 7/8" hole, you'll need a 1/2" knockout plug. Next, go buy some knockout plugs. They're sold in small quantities at hardware stores and home improvement stores for about a quarter each.
Next, kill the power to any circuits going through the box you're working on. As GI Joe always thought to himself, "being safe is the other half." Finally, put the plug in the hole. If you bought the right size, it will be nearly impossible to push the plug in to place with just your hands - you'll need to tap the plug in to place using a hammer.
If you want to make the plug super tight and impossible to remove, you could bend the tabs inside the box with a screwdriver. I'm sure some electricians would say this should always be done. The photo below left shows the tabs in their normal position, and the photo below right shows the tabs bent out.
For Truth-in-Housing evaluations, missing knockout plugs are required repair items in Bloomington, Hopkins, Robbinsdale, and South Saint Paul. They're considered a hazard (H) in Saint Paul, and they're a suggested correction (SC) in Minneapolis.
First, determine the brand and type of panel. It will probably say so right on the door. If it helps, take a photo of the label. Next, go buy some filler plates at a home improvement store or hardware store. You'll find them next to the circuit breakers.
Finally, shut off the power to the panel and pop the appropriate filler in to place. This can typically be done without even removing the cover. For Truth-in-Housing evaluations, openings in the front of an electric panel are required repair items in Minneapolis, Bloomington, Hopkins, Robbinsdale, and South Saint Paul. They're considered a hazard in Saint Paul.
Now go forth and fill your holes with impunity.
Author: Reuben Saltzman, Structure Tech Home Inspections
Who inspects the attic insulation in new construction homes? Probably just the person that put it in. Nobody else.
When new houses are built in Minnesota, the municipal inspection departments typically never even stick their head up in to the attic after the insulation gets blown in. I know this because I started asking about it.
At two recent new construction inspections in Plymouth, we received notice from the builders giving us explicit instructions NOT to open the attic access panels during the inspection. It's their house, so they can do as they want. Heck, home builders can choose to not allow buyers to have home inspections at all... but what do they have to hide? As I've written about before, builders should be proud to have their houses inspected.
Case #1: We were scheduled to perform the new construction home inspection on a Friday, and we received the following email on Monday:
"Please note: Please do not go into the attic on this home. The attic access is not meant to be gone into for inspections. It ruins the sealed envelope of the home. This is considered invasive and is not allowed per the purchase agreement."
The buyer fought tooth and nail to get permission for us to go in to the attic to inspect it, but the builder never backed down. Of course, we respected the builders wishes and left the attic access panel alone. That's how that story ends. The buyer may have us come back out to inspect the attic after they own the house, but it hasn't happened yet.
Case #2: A builders rep gave notice to the home buyer that we were not to open the attic access panel. The home buyer, who spoke English as a second language, relayed this information to me. I called the builders rep myself to ask about getting in to the attic, and he was quite insistent that I not open the attic access panel. He even sent a follow-up email to the buyer reiterating this:
"I just spoke with your home inspector – I let him know he cannot cut the access open to the attic. This is standard protocol for us, we never allow the attic seal to be broken while we own the home. Most home home [sic] inspectors understand this is how it works with new construction. The City of Plymouth has done an Insulation Inspection and have signed off on it. (The Certificate is likely hanging on your garage wall)."
I have a hard time believing most home inspectors understand "this is how it works with new construction". All of the best home inspectors I know open the attic access panel to inspect it, even if it means popping open the attic access panel that has been incidentally covered over with a finished surface. Sealed-schmealed. All it takes to 'seal' the attic access panel is about twenty-five cents worth of white caulk.
Despite what the builder said, the attic insulation was never inspected by the city, and never does get inspected by the city. They don't look in the attic after the insulation has been installed. When the municipal inspector signs off on the insulation in the attic, it's standard operating procedure for them to only look at the card in the basement that states the insulation value. That's it. That's all. They're trusting the insulation contractor to get it right. This isn't a knock against Plymouth; this happens all over the Twin Cities.
It gets better. Thankfully, the attic in the garage was open to the attic in the rest of the house, and the access to the garage attic was wide open. Well, almost wide open. It was easy enough for me to set a ladder up and climb through.
Before inspecting the attic, I checked the card in the basement to find what insulation value was supposed to be present in the attic. It said R-44.
To determine how much insulation is needed to achieve an insulation value for R-44, I checked the attic insulation card. This particular type of insulation requires a minimum depth of 14.75" to achieve R-44. Not maximum depth, not average depth. Minimum.
Here's a close-up. Notice the two numbers given - "Minimum Thickness" and "Minimum Settled Thickness." They're the same. The footnote for the minimum settled thickness says "This product shows negligible settling." I've had many people try to explain to me that the depth I'm reporting isn't relevant because insulation settles so much. That might have been partially true with older insulation, but not the new stuff installed today.
I climbed in to the upper attic and found the same thing I find on almost every new construction home that I inspect; insufficient insulation. Far less than 14.75". What was a little different about this attic was that the insulation installer didn't even bother to 'mound up' the insulation around the depth markers to make it look like the proper amount of insulation was used.
By the way, the Minnesota energy code requires those depth markers to be placed in every 100 sf of attic space (N1101.4.1.1), and they all need to face the attic opening. The code was written in a way that makes it easy for building inspectors to inspect the attic insulation depth... so why doesn't it happen?
I also found a few major attic air leaks, which were allowing for frost to accumulate in the attic, and had already started to turn the sheathing black.
If the garage attic hadn't been open to the rest of the attic, how would I have found out about these issues? I'm sure I wouldn't have. This just would have gone on and on until it made a nasty enough mess that there was evidence of it inside the house, and the builder would probably need to deal with it then, many years down the road.
It's not tough to make the attic access panel accessible. I've inspected many new construction homes done by local, custom, high-end builders who take the extra time and spend a small amount of extra money to get this detail right. For example, w.b. builders uses a product called SkuttleTight, shown below, left. For comparison, the standard attic access cover installed by most large builders is shown below, right.
Hmm, which one would you prefer to have on your own house, from an aesthetic standpoint alone? From a functionality standpoint, this product is also far superior to standard attic covers. It makes a nice tight fit at the walls, it has R-40 insulation, and it's weatherstripped to prevent air leaking. The cover can easily be lifted up so the attic can be accessed, and then placed back down and made tight again. It seems to be pretty dummy-proof. All this for about $150, and it's available all over Minnesota.
I asked Tim Brandvold at w.b. builders why he uses this system for attics when he could save $150 by just doing what all of the big builders do. He said he does this because it's pretty much a given that someone is going to go in to the attic, and $150 is a drop in the bucket compared to the price of the house.
I like his style. If I had my way, every attic access opening would be accessible. I heard a rumor that this requirement will be coming with the newest building code changes in Minnesota. If so, wonderful.
Reuben Saltzman, Structure Tech Home Inspections
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