Epoxy Crack Repair of Basement Wall

Specific Inspection Topics Structural Inspections
1

I should start by saying that I’m just a curious (and somewhat worried) homeowner. We bought our townhouse in Sept. 2005 and noticed soon after that there were two cracks in the back wall of the unit. It is a daylight basement so most of the back wall is only about 4 feet high and has two large windows installed above the 4 ft. section. The first crack is vertical and occurs in the part of the wall that is 4 feet high. The second cracks comes off the corner of one of the windows which I’m told is not uncommon. My concern is that both cracks were injected with epoxy resin in Sept. 2006, primarily to keep water from penetrating. Since being injected both cracks have recracked (evidenced by cracking of the epoxy paste used to hold the injection ports in place) and been reinjected. Now the corner crack has recracked for the second time. This time, it appears to follow the original crack to some extent, but then spiders off course a bit, creating a new hairline crack.

Having seen epoxy repairs in the course of your work, what has your experience been with epoxy injection? Is it typical for it to recrack, and so soon? The cracks were less than 1/8" to begin with so it’s possible that the epoxy wasn’t able to entirely penetrate the depth of the wall.

Thanks for any insight…JB

The vertical crack is behind the ladder in the picture. The corner crack is on the other end of the wall, not visible in the picture.

back wall2.jpg

2

What kind of load is above the wall. Is there anything out of the ordinary, like a 1000 gallon fish tank, etc.?

3

Nothing out of the ordinary…just the kitchen…

The 120 Gallon fish tank is in the basement itself…:smiley:

4

Jay,
How high is the dirt outside ?

5

It’s really pretty silly to try to stop water intrusion from the inside.
A better repair would be dig down the full depth in just the area of the crack.
Then seal it with any number of sealent and water barrier products out there.
From your photo and information , less than 1/8 " is not a big deal and is really not surprising when you consider the fact there is nothing to keep foundation from being pushed in a little. Hopefully ,a well anchored sill plate might help keep the wall in line.
If there is dirt pushed up to the outside it will always be pushing against the foundation.
If the crack gets bigger , or worse, the wall moves in opposing directions side by side or up and down you might look at getting an engineer.

6

Is the back wall built on a slope and is it a block wall or a poured concrete wall. It almost looks like a poured concrete wall but I can’t tell from the picture. If it is a poured wall and what I think is the vertical crack you’re referencing, it appears to be in a joint that was not properly tied together forming a cold joint. The correct answer would be to contact a structural engineer to inspect your foundation for settlement issues.

7

No cold joint there.That’s the epoxie fix I think you are seeing.
And it’s definately a poured foundation…You can see the form panel joints as in any other poured foundation.

8

The foundation is poured concrete and ckratzer is correct…the crack is not in the joint. I agree that fixing from the outside is the correct fix. The builder paid for the epoxy injection (done by separate company). If water penetrates again, we will dig outside. On the part of the wall in the picture, grade is about 8 inches below the top of the short section. If you’re looking at the wall from the inside, as you move left to right, the grade starts declining, so by the time you get all the way over to the right hand side (not pictured), there may be a foot or so below grade. I have not had an engineer look at the wall, but there doesn not appear to be any displacement. The builder, codes office, a few waterproofing guys and a home inspector saw the cracks before they were epoxied. No one seemed alarmed or felt that they were more than shrinkage. I guess my concern is that there is still some “movement” for the crack to re-crack. Perhaps it’s just recracking because the crack wasn’t entirely filled with epoxy…they were pretty narrow cracks.

Thanks,
JB

9

No problem.
If you do get an engineer he/she is going to look for re-bar failure , footing failure,and soil issues. Just so you know.

10

Jay, as you said, the one crack was repaired two times already and is cracking again? The only thing that will make concrete move this much, this fast is something (or nothing) under the wall. The concrete will not crack on its own this many times after drying unless there is an outside pressure on it.
Does the crack get bigger from bottom to the top?
It is time for a structural engineer to assess this situation.

11

I guess I’m questioning the quality of the repair…It’s not that I’m against bringing in an engineer, but isn’t it possible that if the crack wasn’t fully injected due to its small size, that even the slightest bit of movement would cause it to recrack in the same place. Similarly, if there was a crack in a piece of drywall and I patched with a thin coat of spackle, the crack is still there underneath which means that any movement will likely cause the crack to recrack in the same place. Maybe concrete doesn’t work that way…I’m just asking. I put a level on the wall tonight and there is not any displacement. Prior to being injected, the builder simply caulked it (it was like that for a year) and we didn’t notice it getting worse. It has only been since the epoxy that we’ve thought it could be an issue.
Thanks!
JB

12

Temperature changes will cause expansion and contraction in concrete .Even when it is cured.
That is why the exterior fix is the way to go.Foundation coating and heavy mill plastic over the crack will move with expansion and contraction.
If the footing was broken one would most likely see some foundation displacement or heaving.
Jay I don’t know where your house is , but if you are in a region that freezes and thaws all it would take is water freezing in the crack to cause movement.As you probably know,water expands when it freezes

13

Buzz,

50% or so of Injections in poured walls will re-leak, any part or all of a crack can widen. At least this builder did something, some don`t.

Injections are NOT whats best for the homeowner short or long term, they are whats easiest and best for builder and many Inside water-diverting Co`s.

Yep, more difficult/laborious to fix cracks correctly on the outside, its called work, sweating ones butt off and doing it right. Its a lil more costly to Mr Builder as well, that`s why they do what they do.

Add to that, MOST basement walls are not Waterproofed and backfilled correctly, among other things. Just about all homes-basement walls are, at best, parged or damproofed and not backfilled with most-all gravel. If basement walls were Waterproofed and backfilled correctly when built, as well as other important steps like using vertical reinforcing rod, homeowners would have LESS cracks, leaks,bowing walls. NOT talking about a ton more money either. The ones in charge, like most of our politicians, either dont know,are being misinformed, and maybe don`t care. Same old story in this country :wink:

Cracks can occur from several things, from onset cause could be from poor backfilling practices like, the operator of backhoe/front end loader simply being too close to basement walls. Yes, using heavy equipment(the weight of) next to/near a basement wall causes an underground springlike force that is at least partially transmitted to basement wall, could cause damage/crack in basement wall.

Crack(s) could occur from compaction-process, compacting the soil could cause a crack in bsmt wall.

Crack(s) can occur within couple months or coming year or so from the settling of the soil against a basement wall. As soil settles with coming rains it compacts and creates pressure against the outside of the wall, sure it does :wink: Some are shrinkage cracks.

Sometimes thickness or depth of footings cause problems, weather conditions when built…lots of rain on site can cause more/future settling…and other factors.

see --COMPACTION
http://www.bobvila.com/HowTo_Library/Why_Foundations_Fail-Foundation-A2095.html

“…Problem is that the pressure from the compacting process gets transmitted through the soil to the wall. Basement walls have been known to CRACK or fall over while earth is being dumped against them Or Compacted around them…”

“After compaction, Soil is under compression like a spring and…CONTINUES to push against the foundation as it tries to expand…in practice, sands and gravels densify or compact more readily than silts or clays, creating LESS of this springlike Force–one more good reason to use them for…BACKFILLING” …got milk?

–Careful on the Construction Site

“When there`s a heavy load on the ground next to a foundation, some of the PRESSURE is transferred to the WALL. During construction, bulldozers and trucks that come near a basement wall can add enough surcharge-pressure to damage the wall.A new building being built near an existing basement can also INCREASE the Underground pressure and damage the existing foundation…”

See what Yoder Group knows, 6th paragraph…

http://www.yodergroup.com/concrete.asp

Or how about what this link says, see --Basement Walls and…
–Diagnosing the PROBLEM

http://www.fairfaxcounty.gov/dpwes/publications/marineclay.htm#2

http://www.fairfaxcounty.gov/dpwes/publications/marineclay.htm#4

among other things… “the appearance of foundation wall cracks does not necessarily mean that you have a structural problem”

King Crimson… on soft gray mornings widows cry, the wise men share
a joke. I run to grasp divining signs to satisfy the hoax.
The yellow jester does not play but gently pulls the strings
And smiles as the puppets dance, in the Court of the
Crimson King

14

It’s about time you got here john.
Where ya been?? huh??

15

Sounds to me to be a setlement Crack.
If it has been repaired more then once you need to get a propoer company to come in with an engineer to asertain what is involved .
This can be a major fix and bandaids will not do it .
It might require goning down with piers and boots under the foorings to gain the support required for a proper fix.
More information would be nice example what area is the home ,could it be built on fill or unstable ground,is there a rising and falling water table.
You will not get your fix from us we are home inspectors and you need to get profesional help.

I have seen the fixes for settling and it is not simple or cheap.
Roy Cooke

16

Our townhome is in Pennsylvania. The builder told us that our building was built on virgin ground. I’m not trying to disagree with the assessment that it’s a settlement crack, but it could be observed soon after the foundation was poured and a neighboring unit has a similar crack (visible from the outside…it’s a model unit with a finished basement). Plus, I’ve read several times over that cracking off a corner is very typical in residential construction where the concrete isn’t reinforced there. What I was really trying to get at here was whether or not you’ve seen epoxy repairs fail. My feeling is that it’s an issue with the repair. The epoxy is supposed to be stronger than the concrete. If that’s the case, the entire crack should be parallel to the original. In our case, it appears to be cracking in the same spot for the most part. No heaving or displacement from what I can tell.

Also, water table does not appear to be a problem. We have a sump and despite a lot of rain last year, it never fills up…neither do our neighbors’ sumps.

I’ll try to take a picture tonight. Thanks…JB

17

Cheremie, how ya been? as always, you dole out good advice :wink:

and Buzz… not every SE will give you same cause/remedy and that means, just like waterproofing contractors etc, some are much better than others on these matters.

Epoxy stronger than concrete, lol, some like to use this/say this, hey, guess whats stronger than epoxy-concrete? How about expanding-contracting soil pressure,lateral-hydrostatic soil pressure on outside of many–not all walls.

Simon and Gar… “making love in the afternoon with Cecilia up in my
bedroom. I get up to wash my face when I come back
to bed someone`s taken my place” ](*,)

18

Buzz,

…“crack observed soon after foundation was poured”

were the walls backfilled, then the crack was observed?

was the bsmt floor poured before-after backfilling?

any-how much vertical reinforcing rod used?

i`ll assume they used backhoe or loader close to/near foundation wall, that alone ‘could’ cause a crack(s)

backfilling unevenly could cause damage, and so on

http://www.askthebuilder.com/015_Exterior_Foundation_Wall_Waterproofing.shtml

http://www.askthebuilder.com/569_Backfilling_a_Foundation_Wall.shtml

http://www.askthebuilder.com/N4_Thickness_of_Poured_Concrete_Foundation_Walls.shtml

19

Once I even had a concrete truck back into a short wall, much like Jays.,on a spec.I built.
Yes,they did crack it.Yes I was pished.
I repaired it with foundation coat and a heavy mill membrane.That was 6 years ago and it has not leaked… (My home buyers are my friends and I check in with them from time to time).
Oh ,and my primary business is building homes,I carry a hammer not a coffee cup.
I do barely enough inspections a month to call myself an home inspector so I feel quite comfy lending some ideas to this “problem”.
Ultimately , Johns your guy.He works in the field and knows his stuff

20

My experience with epoxy injections, & I’ve done them, is that they work very well. If however, you have movement in the foundation wall it will crack again. Not the fault of the injection. You have a structural problem. Call the engineer quick. It can be a sign of bigger problems to come. Doug