Horizontal cracks in mortar

Need some advice from the pros. Inspected a house today, full basement, masonry block, unfinished. I noticed a horizontal crack on the front wall. The ground slopes towards the front of the home from the road our front. The house is 55 yrs. old. I didn’t see any signs of leaking or moisture anywhere along the front wall. I did see some hairline step cracks, but had to look really hard to find them. All the cracks have been there for a while; no sharp edges, painted a couple years ago with no signs of movement. I’m thinking the wall was moved in the original construction when the back fill was placed. I say this because of the way the mortar is separated from the brick. There are no other indicators of settlement or foundation issues elsewhere in the house. There is no visible bow to the wall, other than the crack and no signs of any attempts at repair. Am I right in my line of thinking?

Evening, Antony. Although I am not an expert, may I ask, where is the CMU, Concrete Masonry Unit wall?
Is this part of the foundation or a stem/support/firewall in the basement?

Could you post a pic of what the wall is supporting above and another at the slab to see if there is a footing.

Hey Robert, it’s a front foundation wall. I’ve attached some photos, but I don’t think they show what you need.

Horizontal cracks should be referred to structural engineer… it does not matter if you are correct, you don’t want to be thrown under the bus by someone for this.


Thanks! You’re The Best!
Please respond, which image as the serpentine mortar crack in? IMG_4081, IMG_4082, IMG_4087 or IMG_4090? Looking forward to your reply.

As for the horizontal head mortar crack. I see serpentine mortar cracking as well.

IMG_ 4095 CMU 1

Personally I would refer this to a licensed foundation block installation and repair contractor. This serpentine & horizontal cracking could be from poor masonry block bond in a stem wall.
Just an opinion mind you but referring a structural engineer is heavy handed and a waste of time and money. A licensed foundation block installation and repair contractor would suffice.
*Note: Likely lot grading requires improvement as well if it is a foundation wall.

To clarify, IMG_4081 is referred to as a stem wall or CMU bearing wall. The structural component above appears to be a steel girder retaining blocked floor joists to prevent rotation.
IMG_4082 has 3 steel columns to which I suspect are bearing a steel girder/beam. Typical of early 1950 construction.

Hey Robert, Thanks a bunch for the useful info. The area in IMG_4081 is an opening to a small area under the front porch, maybe 5x5 at best. In IMG_4082 the steel columns, which are much larger than any I’m used to seeing in a house this size, are actually supporting a wood beam. I’ll do a little more research to bolster my understanding of stem wall vs. foundation wall.

I agree, a structural engineer would be a bit much, that’s why I posted. Normally horizontal cracks present a condition that would warrant a SE, however, I didn’t feel it seemed right in this situation. I’ll keep your opinion in mind when I write my report and say “Robert Young, CMI recommends a licensed foundation block installation and repair contractor.” Just kidding.

Thanks again for the opinion and education. I’ll add it to my book of knowledge.

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Referred to as a , Cold room/Storage area.

“steel columns, ‘which are much larger than any I’m used to seeing in a house this size,’ are actually supporting a wood beam.” Beam >17" Over 17" can be referred to as a girder.
Post 1960’s construction.

Say “Robert Young, CMI recommends a licensed foundation block installation and repair contractor.” is OK with me online. Love Google Juice:-)

Once again you live up to your motto. Thanks a bunch, Robert!

My neck of the woods, IMG_4081 is called a full height foundation wall. Around here a “stem wall” is a short foundation wall that gets backfilled on both sides, and maybe extends 3-4 courses above grade, like what you’d see at the perimeter of a garage.

How much out of plumb was this wall? ( I always carried a plumb bob for these types of situations.):

Question @aponder not @srechkin…mea culpa.

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Some many even say, Larry back then, Bob’s your uncle. Lol.
I have one in my tool kit. Been there for 10 years. Gets the job done.

Many times, after a home’s erected there are modifications to the lot. Walkways, Driveways or deck construction come to mind. Pier work is the most common to bear load for a front porch.
During excavation, unnecessary forces in the soil by an excavator or other machinery operator may/can affect the perimeter drainage field, weep tile and the foundation negatively. In this case, I suspect this is what happened.

How much out of plumb is not a concern? :slight_smile:

…Zero…I was just curious…an SE it is.

Hey Larry, that’s a gig on me. I didn’t have my bob with me.

Hey Larry, I know this may seem like a stupid question, and probably because it is, but when you use a plumb bob how do you secure it at the end? My problem is that I can get up on the ladder, hold the bob, and have it hang where I need while holding it, but then I’ve got to get down off the ladder to take photos. I don’t want to go around driving nails into other peoples houses and sometimes there’s no wood to nail it to; e.g. CMU wall. Do you set up your plumb bob for photos, or is it for self edification in knowing there’s a problem that you then use a different tool to document? Thanks.

All you need in this case is a straight edge right on that crack, and if it shows a bow, there is a problem.


If needed, I used a push pin.

Licensed PE, been looking at cracks in structures since the 1980’s.

The hard thing about bowed wall surfaces is that I find that workers don’t build walls plumb in the first place… so a bowed wall condition could be the original as-built condition, without any forces causing it to bow later. It is a piece of the puzzle though. To be included in all the clues available to you when inspecting and finding cracks.

Thin hairline cracks and narrow cracks in cementitiuous materials (brick, block, concrete, mortar, grout, etc) less than 1/8" wide in buildings that are over 20 years old are almost never structurally significant, UNLESS there is evidence that the cracks formed recently, like in the last few years.

In my humble opinion, Your first instinct was right on. The cracks likely formed in the first few years (in the 1950s), and they have not changed in size since then. That is the definition of stable.

In addition, if there is no evidence of structural distress anywhere else in the home, in the basement or at the floors above, as you said, then it is VERY unlikely that there is any active or even past settlement going on. If the crack is only 1/8" wide in 50 years… Whatever forces or conditions that caused it to crack have stopped, so … Patch it, and call it a day.

Inspector TIP:… remember there are numerous causes for cracks forming BESIDES “settlement”. Try to avoid using that word in association with cracks…unless you can prove settlement is or has happened. Using that word implies that you KNOW settlement is or was going on, now or in the past, and that the crack formed from settlement. If it formed from shrinkage, or thermal expansion and contraction, or frost heave, or corrosion of embedded items, or whatever, then “settlement” had nothing to do with it. Just call it a “Crack”. Let someone else figure out whether or not anything is or was settling.

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