• POST a QUESTION or COMMENT about damaged concrete block foundations: causes, crack & movement patterns, diagnosis, repair, inspection procedures

1. Approaching Blocks Cracks
2. Approaching Blocks Cracked

A cracked engine block might seem like an absolute disaster for your car. As the engine block is one of the most vital components of your vehicle, a damaged block can create numerous problems and consequences. If you see signs that your engine block is cracked. Floor-to-ceiling vertical cracks, uniform in crack width, on opposing basement walls Lateral displacement into or away from the basement: top row of blocks form a step crack that catches your fingernail - approx 1/16' displacement - these blocks are above grade level There are no apparent cracks in walls or exterior bricks. Fracture patterns resulting from point-like impact acting perpendicularly on the plane of a commercial sodalime glass plate is modelled by a spring-block system. The characteristic patterns consist. Test lives 22-30 269-460 Blocks Calculated without sequence 69 1 300 Blocks Calculated with sequence 10 170 Blocks The numbers quoted above are for lives to the appearance of obvious cracks taken as 2.5 mm long.

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Damaged masonry block foundations & walls:

How to Inspect & Diagnose Concrete Block Foundation Cracks, Leans, Bows, Settlement.

This article explains concrete block or 'cinder block' or concrete masonry unit (CMU) foundation inspection procedures and the diagnosis of cracks, bulges, leaning, bowing, and settlement in concrete block foundations and building walls such as damage due to impact, settlement, frost or water damage, and other causes.

Types of foundation cracks, crack patterns, differences in the meaning of cracks in different foundation materials, site conditions, building history,and other evidence of building movement and damage are described to assist in recognizing foundation defects and to help the inspector separate cosmetic or low-risk conditions fromthose likely to be important and potentially costly to repair.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

How to Identify, Diagnose, & Evaluate Masonry Block (concrete & 'cinder block') Foundation & Wall Damage

Article Series Contents

[Click to enlarge any image]

Bulged, collapsing concrete block walls

The masonry block foundation at the house in these photographs collapsed after a period of heavy rain. The underlying problem was in-slope grade at the rear of the home and trapped roof spillage there, causing lots of heavy wet earth pressure on the wall.

The home inspector had previously observed water damage at the wall and had correctly assessed the outside conditions.

The owners had deferred action to prevent further water damage, leading to an unexpected and sudden precipitous collapse of the foundation after a period of unusually wet weather.

Photo below: photograph courtesy of Alan Carson, Carson Dunlop, Toronto. The photos above and below are of two different buildings.

Diagonal Cracks or Step Cracks in Block Walls & Foundations

A diagonal crack can appear in many structural materials and components including block, brick, and concrete foundation walls, chimneys, and and building interior drywall or plaster.

Diagonal cracking usually indicates actual vertical movement in the structure or differential settlement: diagonal cracking in masonry structures usually indicates differential settlement, occasionally frost heaves and more rarely the development of a sink hole under or near the foundation.

Our photo above, discussed

at VERTICAL MOVEMENT IN FOUNDATIONS,

illustrates severe structural damage to a concrete block foundation wall.

Closer inspection shows both stair-step cracking and bulging in this wall, probably due to water and frost pressure from outside.

Diagonal cracks (actually in the form of a stair-step in masonry-unit walls) can appear anywhere in a wall but most often they appear near the building corners.

Explanations for the diagonal or stair-step cracks in concrete blocks or bricks near a corner include at least these factors:

1. Vertical movement is being caused by settlement, frost, or a sink hole or expansive clay soils under and near the foundation wall;
2. The added resistance to movement afforded by the nearby intersecting wall at the corner causes cracking to appear in a stair-step form following the mortar joints in the concrete block or brick whereas the same settlement or heaving forces might have caused more nearly-vertical cracks if they had occurred closer to the center of the wall.
   In our concrete block wall crack photo shown below you can see both step cracks at the wall corner and a horizontal crack at the bottom of the upper 1/3 of the wall - describing what I think is just this condition.
3. In areas of freezing weather or expansive soils, spilling of a roof drainage system downspout by the building corner may be concentrating water in that location.

See DIAGONAL CRACKS in BLOCK FOUNDATIONS, WALLS for details about diagonal cracks in both concret block and poured concrete foundation walls and for advice about evaluating the severity of damage.

See DIAGONAL STEP CRACKING in BLOCK or BRICK FOUNDATIONS for more details.

Cracks occurring near foundation corners in a masonry block wall are often from water and frost. In freezing climates, 'frost lensing' can cause soil to stick to and lift a building foundation when the ground freezes.

These cracks are usually visible in the portion of the concrete block foundtion that remains above grade. The forces at work and this stair-step plus horizontal block wall crack pattern are described in point #2 of the discussion just above.

Horizontal Cracks in Masonry Block Walls

Horizontalcracks in a concrete block wall are more immediately threatening of serious collapse than vertical cracks.

But for small horizontal cracks (say 1/16' wide) and walls that have minimal bowing (say < 1' inwards) the block wall foundation collapse risk estimate may be reduced.

And where history indicates that the damage is old, perhaps from a single event (damaged during backfill, for example) and not ongoing, the urgency of repair may also be reduced.

See BLOCK FOUNDATION BACKFILL DAMAGE

An assessment of these factors as well as the effect on the rest of the structure are important.

The photo at above eft illustrates severe bulging in a concrete block foundation wall. The location of the cracks combined with outside observation of backfill level suggests this damage is due to water, frost, and earth pressure.

In masonry block construction, foundation or wall cracks occur more commonly in mortar joints but can also occur across and through the blocks themselves.

At left we illustrate a wide horizontal crack along the mortar joint of a concrete block foundation wall. The wall also is bulged inwards; measurements showing more than in inch of inwards bow meant that expert evaluation (and probable reconstruction) were in order for this structure.

Vertical Cracking in Concrete Block Walls

Vertical cracks in block foundation walls & expansion and shrinkage cracks in a concrete block wall may occur but are less common than in some other materials.

The National Concrete Masonry Association, in TEK 10-1A (NCMA 2005) describes these types of shrinkage that can cause cracking in concrete masonry walls:

• Drying shrinkage in concrete blocks or masonry units
• Temperature-fluctuation shrinkage in concrete block walls or foundations
• Carbonation shrinkage in masonry block walls

Watch out: more-dramatic concrete block wall damage can occur from external forces such as impact or earth loading.

Above: a very straight vertical crack in a concrete block foundation wall, extending from the basement floor slab to the top of the foundation wall.

Details about the causes of vertical cracks in concrete block walls, and the possible causes and need for remedy or repair for this crack damage are discussed

at VERTICAL CRACKS in BLOCK WALLS

Also see VERTICAL MOVEMENT IN FOUNDATIONS

Approaching Blocks Cracks

Spalling Concrete Block Walls & Foundations

Spalling is defined as the flaking off or loss of material in masonry block, brick, concrete or other masonry structures, usually caused by the action of freezing water that has penetrated the masonry surface. Spalling damage ranges from cosmetic to serious, costly and dangerous.

Spalling concrete block may tell us about the the history of building construction, movement, events can help diagnose concrete block foundation cracks & damage.

If there is superficial spalling of the block - less than 3/4' deep into the block surface, and if there is no bulging, cracking, settlement, movement, crushing, then most likely we're talking about a water entry and moisture issue and a cosmetic issue. Below the spalling concrete block foundation wall damage is in my opinion superficial and cosmetic, not structural, but it does tell us

1. that there has been water or roof spillage by the foundation wall
2. there may be water entry inside the basement or crawl area of the building
3. that someone knew of this condition as the foundation in one of the photos was painted with a masonry sealer.

The photos of spalling concrete block foundation walls shown above were contributed by Kinston NY home inspector Arlene Puentes.

See ABOUT InspectApedia.com for her contact information.

We use the term concrete blocks in these articles where others may refer to this same construction material as concrete masonry unit (CMU), masonry blocks, cement blocks, or cinder blocks. Concrete blocks vary in quality, mostly as a function of the era in which they were made and the raw materials used.

Structural Damage From Spalling Concrete or Masonry Block

At above left the chimnney has been badly damaged by frost: even inspecting from the ground we can see cracks, movement, spalling concrete blocks, and stains indicating that the flue interior is leaking to the chimney exterior.

This is an unsafe chimney risking fire or other damage: inspection and repair or replacement are urgently needed.

The photograph at above right illustrates severe spalling damage to a concrete block pilaster. This is enough damage to be considered a structural concern as the pilaster is part of the structure supporting the building above.

Some concrete block, particularly older masonry block containing a high percentage of sand, cinders, or dirt and not enough concrete may be more vulnerable to water damage and spalling damage.

Henry Page Sr. in Poughkeepsie, NY in the early 1900's dug up the family farm, mixed dirt, cinders, and cement using a Sears & Roebuck cinder block kit to make masonry blocks that were used throughout Dutchess County.

In time many of these blocks spalled and disintegrated badly where they were exposed to rain splash-up at ground level. But rarely did these flimsy versions of the modern (and harder, stronger, concrete block) lead to a building failure from their innate properties.

Rather most building failures involving concrete block are our own fault - causes which we inventory in this article series.

Spalling brick at chimneys and at structural or veneer walls are discussed separately at

and at BRICK WALL FROST & WATER CRACKS, EFFLORESENCE, SPALLING

Key Defects List for Concrete Block Walls

Some common masonry block (or 'concrete block' or 'cinder block') foundation or structural wall defects to be observed and reported include:

• Leaning or tipping masonry block walls: a concrete block or concrete masonry unit (CMU) wall may tipinwards at its top (a leaning or tipping wall failure) due to pressure from water and wet soils, from frost, from theweight of nearby vehicles driving along the wall (oil truck coming to deliver heating oil), or by defects and tipping wall footings.
• Buckled concrete block walls: often due to pressure or loading from water, frost, earth, or nearby passage of vehicles -potentially urgent depending on circumstances and amount.
  Bulging or buckling masonry block wall failures (shown at above-left) are also called 'bending' failures.
• Horizontal displacement or 'shear failures' occur in concrete block walls, particularly ones which were built withoutvertical steel reinforcement, and may be caused by pressure from water and wet soils or other forces.
  If we observe portions of a wallsliding horizontally past other wall segments we've found a shear failure.
  A common shear failure can be seen when the bottom courseof masonry blocks in a foundation wall is held in place by a floor slab and when the upper portion of the wall has been pushed inwardsso that the upper blocks are projecting past the lower ones.
  Such walls are also often tipping or leaning or may be buckled andbroken open along horizontal mortar joints in the wall.
• Cracks in concrete block walls: along the mortar joints, or less often right throughthe masonry blocks themselves, can be the result of pressure from water and wet soils, frost, nearby vehicles, ordifferential settlement in a footing.

  If a foundation wall crack is vertical and fairly uniform in width, but the wall onone side of the crack is higher than on the other, we're looking at differential settlement which will probably betraced to the footings.

  If a foundation wall crack is vertical and wider at its top than its bottom, we may be lookingat footing settlement in which the footings have 'bent' and settled unevenly, such as when a footing has been placedover unevenly compacted fill or where there was bedrock or a large boulder under a portion of the footing permittingsettlement such that the footing has settled down on one or both sides of this 'high point'.
  At least one author alsoposed that a concrete masonry unit wall which has a vertical crack near its center and whose crack is wider at its topthan bottom has cracked due to wall shrinkage along its length.
  His explanation was that the top of the wall was freeto shrink but its bottom was held in place by the footing, making a crack wider at top than bottom. Howeverother experts (D.Wickersheim) assert that concrete block walls do not shrink significantly during curing, though wet masonryblocks might change a bit in dimension during drying.

• Crack patterns in concrete or other masonry foundation walls can occur as vertical, diagonal, stair-stepped, orhorizontal patterns which we discuss and among which we distinguish in more detail
  at FOUNDATION CRACK DICTIONARY
  
• Missing components such as headers where the wall has been modified, steel reinforcement wire or re-bar (if required by local codes).
• Missing footings, piers or other reinforcement
• Impact damage which has broken masonry blocks or dislocated them
• Point loading cracks or fractures
• Other cracks through or across concrete blocks as opposed to cracking in the mortar joints.Unlike poured concrete, concrete blocks do not shrink with age or curing. When investigating cracks through concrete blocks, check the other possibilities.
• Poured concrete sister walls, additions of pilasters, additions of steel reinforcement, or repeated re-coatingof a wall with parging cement are all indications of past damage and/or water entry problems that merit further evaluation

Reader Q&A - also see the FAQs series linked-to below

On 2020-07-19 by Alex: what caused this foundation parge coat damage?

Alex said (re-posted by mod)
I am so sorry, I accidentally deleted your message and photo - I am re-posting them below.
COMMENT:Today I saw these strange channels in the thick parging coat on the interior of the garage wall. These are not stains, but actual grooves channeled through the cement.

The largest one is about inch deep. The color is actually a shade created by light coming through the gate.

Any Idea what would these be and what might be a cause? Thanks.

On 2020-07-19 by (mod) - water damage to new foundation parging

Thanks for the interesting foundation wall damage photos and question, Alex.
Water damage to parge coating on foundation leaves rivulet-gouges:
My guess is that there was a leak that occurred when the parge-coat was fresh - before it had hardened, and the leak washed away some of the coating.
Further investigation for hidden water damage or mold may be in order.

On 2020-05-24 - by (mod) -

I can't see enough to know what's happening Sher, but if this is new or recently-set concrete, such as for a foundation or slab edge, and if it's un-coated concrete, then it looks like a void in the surface, possibly where there was an air bubble or inadequate agitation as the concrete was poured against a form.

On 2020-05-24 21:37:42.315906 by Sher

Is this spalling?

I had men tell me while ripping up concrete porch built with house - they covered it up with mesh wire mortar and waterproof but I seen where they need a different approach.

On 2020-04-15 - by (mod) - horizontal cracks or movement usually due to earth pressure

Thanks for the photos and query, Peter.
I cannot see enough from this one photo to offer a diagnosis with confidence but certainly I agree that horizontal cracking in a block wall is due to pressure:

earth loading could be from frost, wet soil, nearby vehicles, or another cause.
See details at HORIZONTAL FOUNDATION CRACKS

The worst case risk is of foundation collapse - not something I'm asserting from your photos

On 2020-04-15 by Peter

I noted this on house inspection. Am I correct that this shearing from hydrostatic ground forces which shifted the whole foundation wall?

On 2020-03-22 - by (mod) - vertical cracking in new block wall: adding rebar?

Todd
I am not smarter than your onsite engineer. I can however offer some observations:
1. the vertical crack suggests that the adjoining wall that is not visible has rotated outwards and will be out of plumb
2. the crack pattern may indicate that the wall was built without sufficient steel reinforcement in the horizontal courses - or none; Adding that now is infeasible. (I do see some vertical rebar at intervals that helps protect against horizontal cracking - buckling, but one can't see any horizontal)
3. where does the engineer intend adding re-bar? How will that prevent additional movement in these walls due to loading and future settling of fill?
4. How much fill is being added inside this foundation wall - to what height? How will the fill be compacted so as to prevent future settlement?
5. Will the slab be pinned to the foundation walls or floating? What reinforcement will be used in the slab itself against settlement cracks?

On 2020-03-22 by Todd

Going to see what you thought about this.. 9 and 1/2 foot u block wall toward rear.. cracked when they were filling with fill.

Have three good size cracks.

Engineer decided best thing to do was add rebar before pouring slab.

Picture I added was worse of the three cracks.

On 2020-02-19 - by (mod) - step cracks on block foundation wall

Pete
It'd be no surprise to find some mold growth on concrete block foundation walls, particularly where paint has been applied but also where there may be organic dust and debris.
The stair step crack pattern is often related to settlement or to frost heaves.
Take a look outside the same area for roof spillage, surface runoff, and take a look inside for a history of water entry.
Then you'll want to

review FOUNDATION DAMAGE SEVERITY

As I don't see obvious extensive water entry signs in your photo - such as rotted sill plates - it's possible that the mold is related to moisture penetration into what was a fiberglass-insulated wall cavity against cool concrete block foundation walls.

'A crystallization' might be mineral salts or effloresence left behind from foundation wall leakge.

See EFFLORESCENCE SALTS & WHITE DEPOSITS

On 2020-02-19 by pete

Wondering your assessment on this cinder block...we had a water leak in the corner so we took down the drywall and the insulation and this is what we see.

Looks like someone painted it yellow but a contractor told us that is not mold but appears to be a crystallization?

Approaching Blocks Cracked

I have a couple more pics but it looks like you only allow one upload.
Thanks

On 2019-12-05 by Mike

Yea, I figured they just were too embarrassed to admit they were wrong. In the email that they suggested that I contact a structural engineer that is qualified to answer and assess the spalling. The funny thing is, their website says they specialize in all this. Oh well.
I came to question their assessment as I was Googling spalling and concrete damage to educate myself -- the information I was finding conflicted with what they said.

Being wary of the pitfalls of internet research, I came to forums and pages like this to pose my question so SMEs and sort out the discrepancies. Thanks to you I was able to confirm my beliefs in what I found.
I ended up getting a mason out there who was really good at explaining everything and his assessment seems very reasonable. His assessment is the re-bar swelled from rusting and broke up the concrete from the inside. He then explained the other smaller cracks and what they could and couldn't mean and what they were probably caused by.
Thanks again for having such an informative site and also for taking the time to answer questions for us commoners.

On 2019-12-02 by (mod) - example of spalling concrete block

Spalling is defined as the flaking off or loss of material in masonry block, brick, concrete or other masonry structures, usually caused by the action of freezing water that has penetrated the masonry surface.
Spalling can also be caused by the forces of mineral crystal or salt formation as moisture passes through and evaporates from the surface of masonry materials, causing lifting off or flaking of the surface.

Spalling is usually used to describe flaking off of the surface of brick bolck or stone.

My photo is of badly-spalling brick on the lower walls of a building in the Dosoduro section of Venice - a city increasingly subjected to flooding and water damage as tides are higher and storms more severe as global warming progresses.

In its most-general sense,

'Spalling' means 'flaking off of the surface' of the material of a larter solid body of masonry - concrete, concrete block, brick, occasionally stone.

Definition of Spalling or Spall - A small fragment removed from the face of a masonry unit by a blow or by action of the elements.- Masonry Institute - http://www.masonryinstitute.com/wp-content/uploads/MIW-Pocket-Guide.pdf
This is similar to my definition
The most-extreme disintegrating concrete block in the photos I suggested earlier is in my opinion something worse than spalling - spalling is usually a surface defect.

But a concrete block that was made of improperly-mixed materials - for example chinching out on the amount of portland cement in an old concrete block or 'cinderblock' can show up first as surface spalling but as the blocks are found to be soft and crumbling and literally disintegrating I would consider that to be a material defect in the original manufacture of the block - and very serious if the block is part of a structure.

(That's not your block).

On 2019-12-02 by (mod) -

In my opinion the reason that it is really important to call masonry damage by its correct name is that the understanding type of damage (cracks, spalling, bulging, leaning, settlement, heaving etc) is absolutely critical in diagnosing the cause, assessing the impact, and prescribing necessary actions.
If my doctor can't tell the difference between a broken bone (a very severe 'crack') and heat rash (a skin surface condition) then I doubt that she will make a useful diagnosis and her prescription for treatment is ... well ... going to leave me nervous as all get-out. Same for my 'engineer'.

Engineers vary considerably in their actual specific training: structural, civil, chemical, mechanical, electrical, for example. It sounds to me as if either there has been a serious mis-communication somewhere or your engineer isn't familiar with masonry construction.

On 2019-12-02 by (mod) - Mis-use of terms: 'spalling' caused by water or moisture or effloresence damage to masonry surface;

cracks in masonry caused by stress, force, movement or impact

Spalling is usually caused by water penetration of the surface of masonry, often combined with freezing, to force off flakes of material from the surface of the masonry brick or block or occasionally concrete surface. Spalling always occurs beginning at the surface of masonry.
Cracks occur from mechanical forces such as impact, bending, settling, heaving that cause actual breakage of the material (as the most-common crack though there are also 'shrinkage' cracks in concerete and thermal expansion cracks in brick).

In all cases there is a mechanical force and a breaking of the material in lines or ... cracks.
This photo is a vertical crack near the corner of a concrete block wall.

This is Not spalling.

Compare it to your photo. Your wall crack is also roughly vertical but not as straight.

On 2019-12-02 by (mod) -

Mike that is indeed disappointing - or we're not looking at the same thing.
Spalling is a crumbling or flaking off of the surface of masonry - in your case masonry block.
Cracks appear as lines or gaps between surfaces of the material. You *might* see a little weathering at the very edges of such cracks at the outer surface of the block but no mason would call cracking spalling.
With all due respect to your engineers, you might want to look

at SPALLING CONCRETE BLOCK WALLS & CHIMNEYS
where you will see thin spalling that was painted over, and such severe block spalling that an entire thickness of the block wall has been lost - in other photos.
Spalling: think flaking or crumbling.
Cracking: think separation in masonry forming a linear gap, usually irregular, of varying width depending on the crack type and severity.
There is one case in which we might see a bit of concrete block that chipped away along the edge of a crack - I'll attach a photo. However if you look with any sense at all at the photo you'll see that the chip occurs along the edge of a crack; this is crack damge. Spalling is shown at the link I gave.
Sometimes people are embarrassed to admit they made a mistake or don't know something. In my opinion we gain credibility rather than lose it when we make it clear that we're not going to bully or B.S. the client.

On 2019-12-02 by Mike - Structural engineer says this wall damage is 'spalling'

I just got an email reply from that structural engineering company. They looked at the photos I sent and still say it's spalling. I guess that would be the first clue to not hire them for any structural engineering work. LOL

On 2019-12-01 by (mod) -

I'd look carefully at footings and floor-wall junctures for movement, water entry, insect attack through gaps;
Generally when a wall tips or leans the distance and separation is greater higher in the structure;

On 2019-12-01 by Mike

I'm glad to hear that it is repairable, that is a relief. Now I just have to find out how involved and expensive a fix will be.
Given this damage, are there other things I should be keeping a lookout for or be aware of?
Thanks for the information and confirming I'm not crazy. I was pretty sure it wasn't spalling but was doubting myself after that guy from a structural engineering company said it was. .

On 2019-12-01 by (mod) -

Often in that location the type of crack that your photo shows is being caused by a rotating or tipping of the footing on which the wall rests.

Ultimately the wall may need to be repaired or to be pinned back to the remaining foundation wall.

In a severe case it may be necessary to repair the supporting footing first.

At the very least you will want to keep roof spillage and water away from the foundation and footing to reduce that rate of settlement or movement.

On 2019-12-01 by Mike

Yes, the house is on a slight slope and the crack is on the downhill side.

There are some horizontal cracks around the corner high on the wall. I thought it was settling or shifting but I can't find any cracks in the foundation or in the cement walkway that goes in front of and around the side of the house in that area.

On 2019-11-29 by (mod) - what's the difference between 'spalling' and 'cracking' in a concrete block wall?

Of course it's not spalling, Mike, your photo shows a vertical crack, irregular, passing through the conceret blocks near a building corner.
Is this house built on a slope or Hillside?

Is this crack on the downhill side?

On 2019-11-29 by Mike

Could you please give your opinion on this wall? The house was built in 1955 with concrete blocks. It's located in a tropical and rainy climate. The house has several cracks on the exterior walls. There are two vertical cracks that go up each side of a window and are about 5' long.

They are on both sides of the wall -- I'm assuming they go completely through the brick. Around the corner and high on the wall there are a couple of horizontal cracks about 2' long. The crack width is small in comparison to the vertical cracks. There are no cracks in the foundation or walkway that goes around the house

. When I called a local company, the guy on the phone said it was spalling without looking at any photos. From what I can find on your site (and other searches), this does not look like spalling. I have several photos but the site only lets me upload one.

On 2019-11-13 by (mod) -

I'd like to see photos, Pam (you can post one per comment) but I can in the interim suggest
1. the lower wall may have been pushed in by frost or earthloading but the break occurred at a mortar joint near the wall top where the top course of block are perhaps pinned to the sill plate
2. less common except in earthquake areas - the building framing was shifted or moved horizontally - in which case typically you'd see the identical damage on the two opposing foundation wall sides
I'm a bit confused by the latter part of your question: a wall can't also be a driveway, right?

On 2019-11-12 y Pam

first row of blocks re ceiling of crawl space, horizontal 6 ft. crack 3- 4 blocks , slight lean, towards the EXTERIOR OF THE HOME.

note yes the blocks are to code over 16 inch below frost line

we live in Ontario Canada.... unfortunately my husband did not notice this issue until now
why would cause the blocks to lean towards the exterior of home, the wall in question is a interlock brick driveway that is sloped downward towards the road

On 2019-10-29 by (mod) -

Cory: to have room to comment and to collect your photos together please find your question and our reply now at
BLOCK FOUNDATION WALL DAMAGE FAQs

On 2019-10-28 by Cory

Should these cracks be sealed with mortar filler to avoid moisture coming into the basement?

...

Continue reading at BLOCK FOUNDATION BACKFILL DAMAGE or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see BLOCK FOUNDATION WALL DAMAGE FAQs - questions and answers posted originally on this page

Or see these

Concrete Block Foundation & Wall Damage Articles

• BLOCK FOUNDATION & WALL DEFECTS - home
• FOUNDATION CRACK DICTIONARY for descriptions of different crack patterns, causes, repairs
• FOUNDATION DAMAGE & REPAIR GUIDE - home
• FOUNDATION FAILURES by MOVEMENT TYPE - home
• FOUNDATION FAILURES by TYPE & MATERIAL - home

Suggested citation for this web page

BLOCK FOUNDATION & WALL DEFECTS at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

INDEX to RELATED ARTICLES: ARTICLE INDEX to BUILDING STRUCTURES

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Technical Reviewers & References

• NCMA, CRACK CONTROL IN CONCRETE MASONRY WALLS [PDF] TEK 10-1A Movement Control (2005), National Concrete Masonry Association, 13750 Sunrise Valley Drive, Herndon, Virginia 20171-4662 USA Website: www.ncma.org
  source: AIA Continuing Education Series, http://alconcrete.org/wp-content/downloads/cworks-presentation-lee.pdf
• Saxer, E.K. & H.T. Toennies, Measuring Shrinkage of Concrete Block - A Comparison of Test Methods, pp. 988-1004, 1957.
• Standard Specification for Loadbearing Concrete Masonry Units, ASTM C 90-03. ASTM International, 2003.
• Strength Design of Concrete Masonry, TEK 14-4A. National Concrete Masonry Association, 2002.
• Avongard foundation crack progress chart for structural crack monitoring
• Building Failures, Diagnosis & Avoidance, 2d Ed., W.H. Ransom, E.& F. Spon, New York, 1987 ISBN 0-419-14270-3
• Building Pathology, Deterioration, Diagnostics, and Intervention, Samuel Y. Harris, P.E., AIA, Esq., ISBN 0-471-33172-4, John Wiley & Sons, 2001 [General building science-DF] ISBN-10: 0471331724 ISBN-13: 978-0471331728
• Building Pathology: Principles and Practice, David Watt, Wiley-Blackwell; 2 edition (March 7, 2008) ISBN-10: 1405161035 ISBN-13: 978-1405161039
• Diagnosing & Repairing House Structure Problems, Edgar O. Seaquist, McGraw Hill, 1980 ISBN 0-07-056013-7 (obsolete, incomplete, missing most diagnosis steps, but very good reading; out of print but used copies are available at Amazon.com, and reprints are available from some inspection tool suppliers). Ed Seaquist was among the first speakers invited to a series of educational conferences organized by D Friedman for ASHI, the American Society of Home Inspectors, where the topic of inspecting the in-service condition of building structures was first addressed.
• Domestic Building Surveys, Andrew R. Williams, Kindle book, Amazon.com
• Defects and Deterioration in Buildings: A Practical Guide to the Science and Technology of Material Failure, Barry Richardson, Spon Press; 2d Ed (2001), ISBN-10: 041925210X, ISBN-13: 978-0419252108. Quoting:
  A professional reference designed to assist surveyors, engineers, architects and contractors in diagnosing existing problems and avoiding them in new buildings. Fully revised and updated, this edition, in new clearer format, covers developments in building defects, and problems such as sick building syndrome. Well liked for its mixture of theory and practice the new edition will complement Hinks and Cook's student textbook on defects at the practitioner level.
• Guide to Domestic Building Surveys, Jack Bower, Butterworth Architecture, London, 1988, ISBN 0-408-50000 X
• 'Avoiding Foundation Failures,' Robert Marshall, Journal of Light Construction, July, 1996 (Highly recommend this article-DF)
• 'A Foundation for Unstable Soils,' Harris Hyman, P.E., Journal of Light Construction, May 1995
• 'Backfilling Basics,' Buck Bartley, Journal of Light Construction, October 1994
• 'Inspecting Block Foundations,' Donald V. Cohen, P.E., ASHI Reporter, December 1998. This article in turn cites the Fine Homebuilding article noted below.
• 'When Block Foundations go Bad,' Fine Homebuilding, June/July 1998
• Historic Preservation Technology: A Primer, Robert A. Young, Wiley (March 21, 2008) ISBN-10: 0471788368 ISBN-13: 978-0471788362
• Masonry structures: The Masonry House, Home Inspection of a Masonry Building & Systems, Stephen Showalter (director, actor), DVD, Quoting:
  Movie Guide Experienced home inspectors and new home inspectors alike are sure to learn invaluable tips in this release designed to take viewers step-by-step through the home inspection process. In addition to being the former president of the National Association of Home Inspectors (NAHI), a longstanding member of the NAHI, the American Society of Home Inspectors (ASHI), and the Environmental Standard Organization (IESO), host Stephen Showalter has performed over 8000 building inspections - including environmental assessments. Now, the founder of a national home inspection school and inspection training curriculum shares his extensive experience in the inspection industry with everyday viewers looking to learn more about the process of evaluating homes. Topics covered in this release include: evaluation of masonry walls; detection of spalling from rebar failure; inspection of air conditioning systems; grounds and landscaping; electric systems and panel; plumbing supply and distribution; plumbing fixtures; electric furnaces; appliances; evaluation of electric water heaters; and safety techniques. Jason Buchanan --Jason Buchanan, All Movie Review
• Masonry Design for Engineers and Architects, M. Hatzinikolas, Y. Korany, Canadian Masonry (2005), ISBN-10: 0978006100, ISBN-13: 978-0978006105
• Masonry Structures: Behavior and Design, Robert G. Drysdale, Ahmid A. Hamid, Lawrie R. Baker, The Masonry Society; 2nd edition (1999), ISBN-10: 1929081014, ISBN-13: 978-1929081011
• Masonry, Engineered: Using the Canadian Code, J. I. Gainville, Cantext publications (1983), ASIN: B0007C37PG
• Masonry, Non-reinforced masonry design tables, Hans J. Schultz, National Concrete Producers Association and the Canadian Masonry Contractors Association (1976), ASIN: B0007C2LQM
• Quality Standards for the Professional Remodeling Industry, National Association of Home Builders Remodelers Council, NAHB Research Foundation, 1987.
• Quality Standards for the Professional Remodeler, N.U. Ahmed, # Home Builder Pr (February 1991), ISBN-10: 0867183594, ISBN-13: 978-0867183597
• Sal Alfano - Editor, Journal of Light Construction*
• Thanks to Alan Carson, Carson Dunlop, Associates, Toronto, for technical critique and some of the foundation inspection photographs cited in these articles
• Terry Carson - ASHI
• Mark Cramer - ASHI
• JD Grewell, ASHI
• Duncan Hannay - ASHI, P.E. *
• Bob Klewitz, M.S.C.E., P.E. - ASHI
• Ken Kruger, P.E., AIA - ASHI
• Aaron Kuertz aaronk@appliedtechnologies.com, with Applied Technologies regarding polyurethane foam sealant as other foundation crack repair product - 05/30/2007
• Bob Peterson, Magnum Piering - 800-771-7437 - FL*
• Arlene Puentes, ASHI, October Home Inspections - (845) 216-7833 - Kingston NY
• Greg Robi, Magnum Piering - 800-822-7437 - National*
• Dave Rathbun, P.E. - Geotech Engineering - 904-622-2424 FL*
• Ed Seaquist, P.E., SIE Assoc. - 301-269-1450 - National
• Dave Wickersheimer, P.E. R.A. - IL, professor, school of structures division, UIUC - University of Illinois at Urbana-Champaign School of Architecture. Professor Wickersheimer specializes in structural failure investigation and repair for wood and masonry construction. * Mr. Wickersheimer's engineering consulting service can be contacted at HDC Wickersheimer Engineering Services. (3/2010)
• *These reviewers have not returned comment 6/95

Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair

• Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
• Best Practices Guide to Residential Construction, by Steven Bliss. John Wiley & Sons, 2006. ISBN-10: 0471648361, ISBN-13: 978-0471648369, Hardcover: 320 pages, available from Amazon.com and also Wiley.com. See our book review of this publication.
• The Journal of Light Construction has generously given reprint permission to InspectAPedia.com for certain articles found at this website. All rights and contents to those materials are ©Journal of Light Construction and may not be reproduced in any form.
• ...

Sinkholes and Sudden Land Subsidence References, Products, Consultants

• 'A Hole in the Ground Erupts, to Estonia's Delight', New York Times, 9 December 2008 p. 10.
• History of water usage in Estonia: (5.7 MB PDF) jaagupi.parnu.ee/freshwater/doc/the_history_of_water_usage_systems_in_estonia.pdf
• 'Quebec Family Dies as Home Vanishes Into Crater, in Reminder of Hidden Menace', Ian Austen, New York Times, 13 May 2010 p. A8. See http://www.nytimes.com/
• 'Quick Clay', Wikipedia search 5/13/2010 - http://en.wikipedia.org/wiki/Quick_clay
• Florida DEP - Department of Environmental Protection, & Florida Geological survey (http://www.dep.state.fl.us/geology/default.htm) on Florida sinkholes: Effects of Sinkholes on Water Conditions Hernando County, Florida, Brett Buff, GIS in Water Resources, 2008, Dr. David R. Maidment, Photos - Tom Scott, Florida Geographic Survey - Web Search 06/09/2010 - http://www.dep.state.fl.us/geology/geologictopics/jacksonsink.htm
  and - http://www.dep.state.fl.us/geology/geologictopics/sinkhole.htm
  also see
  Lane, Ed, 1986, Karst in Florida: Florida Geological Survey Special Publication 29, 100 p.
• Foundation Engineering Problems and Hazards in Karst Terranes, James P. Reger, Maryland Geological Survey, web search 06/05/2010, original source: http://www.mgs.md.gov/esic/fs/fs11.html
  Maryland Geological Survey, 2300 St. Paul Street, Baltimore, MD 21218
• 'Frost Heaving Forces in Leda Clay', Penner, E., Division of Building Research, National Research Council of Canada, Canadian Geotechnical Journal, NRC Research Press, 1970-2, Vol 7, No 1, PP 8-16, National Research Council of Canada, Accession number 1970-023601, Quoting from original source

The frost heaving forces developed under a 1 ft. (30.5 cm) diameter steel plate were measured in the field throughout one winter. The steel plate was fixed at the ground surface with a rock-anchored reaction frame. heave gauges and thermocouples were installed at various depths to determine the position and temperature of the active heaving zone. The general trend was for the surface force to increase as the winter progressed. when the frost line approached the maximum depth the force was in excess of 30,000 lb (13,608 KG). Estimates of the heaving pressure at the frost line ranged from 7 to 12 psi (0.49 to 0.84 KG/cm) square during this period. The variation of surface heaving force was closely associated with weather conditions. Warming trends resulting in a temperature increase of the frozen layer caused the forces to decline.

• 'Geoscape Ottowa-Gatineau Landslides', Canada Department of Natural Resources, original source http://geoscape.nrcan.gc.ca/ottawa/landslides_e.php - quoting from that source:

  Leda clay slopes in the Ottawa valley are vulnerable to catastrophic landslides. More than 250 landslides, historical and ancient, large and small, have been identified within 60 km of Ottawa. Some of these landslides caused deaths, injuries, and property damage, and their impact extended far beyond the site of the original failure. In spectacular flowslides, the sediment underlying large areas of flat land adjacent to unstable slopes liquefies. The debris may flow up to several kilometres, damming rivers and causing flooding, siltation, and water-quality problems or damaging infrastructure. Geologists and geotechnical engineers can identify potential landslide areas, and appropriate land-use zoning and protective engineering works can reduce the risk to property and people.

  Deposits of Leda clay, a potentially unstable material, underlie extensive areas of the Ottawa-Gatineau region. Leda clay is composed of clay- and silt-sized particles of bedrock that were finely ground by glaciers and washed into the Champlain Sea. As the particles settled through the salty water, they were attracted to one another and formed loose clusters that fell to the seafloor. The resulting sediment had a loose but strong framework that was capable of retaining a large amount of water. Following the retreat of the sea, the salts that originally contributed to the bonding of the particles were slowly removed (leached) by fresh water filtering through the ground. If sufficiently disturbed, the leached Leda clay, a weak but water-rich sediment, may liquefy and become a 'quick clay'. Trigger disturbances include river erosion, increases in pore-water pressure (especially during periods of high rainfall or rapid snowmelt), earthquakes, and human activities such as excavationand construction.

  After an initial failure removes the stiffer, weathered crust, the sensitive clay liquefies and collapses, flowing away from the scar. Failures continue in a domino-like fashion, rapidly eating back into the flat land lying behind the failed slope. The flowing mud may raft intact pieces of the stiffer surface material for great distances.

• Kochanov, W. E., 1999, Sinkholes in Pennsylvania: Pennsylvania
  Geological Survey, 4th ser., Educational Series 11, 33 p., 3rd printing April 2005, Pennsylvania Department of Conservation and Natural Resources / Bureau of Topographic and Geologic Survey, DCNR Educational Series 11, Pennsylvania Geological Survey, Fourth Series, Harrisburg,
  1999 - web search 06/05/2010, original source: http://www.dcnr.state.pa.us/topogeo/hazards/es11.pdf - Quoting from the document introduction:
  The first 18 pages of this booklet contain an explanation of how sinkholes develop. In order to tell the sinkhole story, it is important to discuss a number of related geologic disciplines. The words used to describe sinkholes and these disciplines may be a bit unfamiliar. However, general explanations are given throughout the booklet to help clarify their meanings. Key words are printed in bold type for emphasis. The more important ones are defined in a Glossary that begins on page 29. The remaining sections, starting with “Sinkholes in the Urban Environment” (page 18), deal with sinkholes and their impact on our environment. This includes recognition of subsidence features and sinkhole repair.
• [1] Sarah Cervone, [web page] data from the APIRS database, Graphics by Ann Murray, Sara Reinhart and Vic Ramey, Vic Ramey isthe editor. DEP review by Jeff Schardt and Judy Ludlow. The web page is acollaboration of the Center for Aquatic and Invasive Plants, University of Florida, and the Bureau of InvasivePlant Management, Florida Department of Environmental Protection contact: varamey@nersp.nerdc.ufl.edu [A primary resource for this article
• [2] Center for Cave and Karst Studies or the Kentucky Climate Center, both at Western Kentucky University
• Vanity Fair - web search 06/04/2010 http://www.vanityfair.com/online/daily/2010/06/what-caused-the-guatemala-sinkhole-and-why-is-it-so-round.html
• Sinkholes, Virginia Division of Mineral Resources,
• Virginia Department of Mines, Minerals and Energy, www.dmme.virginia.gov Virginia Department of Mines, Minerals and Energy Division of Mineral Resources 900 Natural Resources Drive, Suite 500 Charlottesville, VA 22903 Sales Office: (434) 951-6341 FAX : (434) 951-6365 Geologic Information: (434) 951-6342 http://www.dmme.virginia.gov/ divisionmineralresources.shtml - Web search 06/09/2010

Sink Hole & Related Engineering References

• Newton, J. G., 1987, Development of sinkholes resulting from man's activities in the eastern United States: US Geological Survey Circular 968, 54 p.
• Sinclair, W. C., 1982, Sinkhole development resulting from ground-water withdrawal in the Tampa Area, Florida: U.S. Geological Survey Water-Resources Investigations 81-50, 19 p.
• White, W. B., 1988, Geomorphology and Hydrology of Karst Terrains: Oxford University Press, New York, 464 p.
• Williams, J. H. and Vineyard, J. D., 1976, Geologic indicators of subsidence and collapse in karst terrain in Missouri: Presentation at the 55th Annual Meeting, Transportation Research Board, Washington, D.C.
• Barry F. Beck, A. J. (1999). Hydrogeology and Engineering Geology of Sinkholes and Karst. Rotterdam, Netherlands: A. A. Balkema.
• Beck, B. F. (2003). Sinkholes and the Engineering and Environmental Impacts of Karst. Huntsville, Alabama: The American Society of Civil Engineers.
• Beck, B. F. (2005). Sinkholes and the Engineering and Envrionmental Impacts of Karst. San Antonio, Texas: The American Society of Civil Engineers.
• Tony Waltham, F. B. (2005). Sinkholes and Subsidence, Karst and Cavernous Rocks in Engineering and Construction. Chichester, United Kingdom: Praxis Publishing.
• Whitman D., G. T. (1999). Spatial Interrelationships Between Lake Elevations, Water Tables, and Sinkhole Occurence in Central Florida: A GIS Approach. Photogrammetric Engineering and Remote Sensing , 1169-1178.
• Cited References from this article:
• #3. Detecting Sinkholes with Geophysics, Enviroscan, Inc., Lancaster PA 717-396-8922 email@enviroscan.comwww.enviroscan.com 2003
• Sinkholes in Guatemala, Guatemala City, Wikipedia - web search 06/04/2010 - http://en.wikipedia.org/wiki/Guatemala_City
• ...

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