This driveway leading to the garage is sloped. The way it’s angled there is nothing beneath it at least at the sides. Bad grading at one side for sure. Is this water erosion/washout over time or was it made this way? I’m not super familiar with installing driveways or concrete.
Don’t know how old the slab is, but it’s erosion caused by poor backfill and no grass. Ever notice how sod cuts hold the dirt on the bottom? Grass can limit erosion by holding the soil together. The solution is backfill and plant. Eventually water running under that slab (the way it’s now exposed) will undermine the slab and cause heaving and cracking.
7 Likes
what Bob said…
1 Like
Yes… BUT… ALSO…
Inspectors tend to overlook the obvious… rainwater striking the garage vehicle door(s) and wall, with no where to go but down… and into the separation to beneath the slab, between the garage slab/wall, the apron, and the driveway! IMO, 99% of the time this is the root cause of driveway slab undermining/erosion!
This condition will only worsen over time. Whatever the repair to the undermining itself is, if the original cause is not corrected (and MAINTAINED) it will just return another day down the road.
.
.
8 Likes
LIMIT… but not eliminate!!
1 Like
Agree. And that area is super low too the expansion seam so water will just sit there and not drain as is. Thanks for the replies. Definitely a problem. Had a driveway like this not too long ago that had reached the point of no return. Ill try and post that later.
Optical illusion??
Yes, the slab has dropped, (likely caused the cracking in the driveway), but not as far as you may think.
Look at the brick veneer. Not much has changed from the original installation level.
All of that old (crap) “caulk” (epoxy sealant) needs to be removed, proper sized backer rod installed, and re-sealed. This may need to be done every 5 years or so, thus my reference to “maintenance” in my other post.
.
.
3 Likes
man just look at all those red pointy things ! 
2 Likes
Gets the attention of my Clients real fast!!
1 Like
I wasn’t trying to suggest the slab had sunk massively. In fact it seemed in pretty good condition atm. I just meant the area was not properly sealed, as you detailed, leaving an area that water can fill and not drain well.
1 Like
backer rod and sealants readily available today are much better than what we had years ago…
2 Likes
Can anybody tell me what the proper way to repair undermining is? I know it’s not our job to recommend specifics but nice to know. I know they have foams for bigger jobs, do you use concrete or even earth for smaller jobs?
Most popular seems to be ‘mud-jacking’, but it has it’s long-term limitations.
1 Like
What you see is so typical. More than likely it started off as settlement at the foundation, then followed by the deteriorating expansion material and erosion. @jjonas pictures and pointers definitely show the cause of the erosion. The other issue is whoever poured the driveway did not put a thickened edge on the slab.
Had a thickened edge been poured at least 6"-8" below what would have been finished grade then you wouldn’t have ended up with this:
It’s probably hollow quite a ways under the slab, but since it didn’t break, it would be safe to assume some sort of reinforcement is in the slab like rebar.
Tear it out, backfill with structural fill, compact, replace slab with an adequate thickened edge, use a “zip strip” on the expansion material and seal the area with a self leveling joint sealant like Sika Flex.
2 Likes
Observation: Exterior. Lot & Driveway.
1: Wide Gap between the driveway slab, garage door saddled. Not sealed/water tight.
Exposed driveway substrate. Poor surrounding driveway grading. Prone to natural excavation.
2: Vegetation, hedges, bushes, plantings to close to critical yard features.
Soil erosion.
Poor soil grading. Soil loss. Soil degradation.
Pervious material. Bark mulch.
2 Likes
Thumbs up on that.
And, if possible create a diversion channel so the water is not just sitting on the self-leveling elastomeric caulk that’s needed. Everything needs to drain.
1 Like
Wow! I definitely disagree. I’d recommend a contractor specializing in foam injection to evaluate it for filling in the void and of course, restore the grading on the edge. That slab does not look like it is within a mile of needing to be torn out and replaced.
7 Likes
I agree with Lon…
If you want to throw money away, then tear the slab out. That is a non optimal repair recommendation.
Home seems to be situated on a hillside. On one side of the driveway adjacent soil angle of repose seems to be finding it’s natural slope. Soil was too steep, so it is washing away. Both sides of garage look to have gutter downspouts nearby, the one side might have water ponding. Soil subsiding possible and the other side hillside erosion IS a concern. The expansion gap water intrusion is often overlooked. More overview pics needed.
2 Likes