The subbase of the concrete steps going up to the front door is exposed and coming out. My concern is whether this is a sign of a bigger problem with how the steps were made. Home is about 1 year old and didn’t note any movement in the landing
If by “subbase” you mean “footing”, there could be some frost heaving, in the future, if that footing isn’t below the frost depth. Which depending on soil, that could be 12" to 42" or more in depth.
I was referring to the crushed stone that is beneath the concrete. Maybe I have misunderstood that to be the subbase? Is this a symptom of improper form or compression of the stone prior to pouring?
It is hard to tell from here but…
I have not seen stones with concrete walls but it is used for pressure treated wood foundations, often, as the footing.
Assuming this is just a walkway and that post is just a railing not a column supporting the roof or anything I dont believe its improper. The patched crack looks more questionable to me rather than the gravel base being exposed. I can’t see enough to say more than an area to monitor for future movement if anything.
It’s a landing a couple steps above grade with another flight of steps that goes up to the front door. Nothing in this area near the home or sharing. I suspect the patch is a larger opening that they chose to fill unlike this opening at grade.
Isn’t the base supposed to be compacted and kept away from the forms?
It’s possible that the steps were poured on a bed of crushed stone and it’s looked like that since it was poured.
The soil beneath poured concrete needs to be compacted if it has been disturbed. I have no idea why they would install gravel before pouring.
Gravel is typically used to fill in the area under the porch because it doesn’t need to be compacted like dirt and it was more than likely what was laying around the site when the forms were set. Also the gravel helps prevent heaving with expansive soil as the little voids in the gravel give the soil somewhere to go when it expands. The contractor didn’t clear that specific area of the forms prior to pouring the concrete, leaving what you see. Just poor Craftsmanship IMO. Most new homes with load bearing posts on the front porch have a footing and short wall under the slab. The footing would be the same depth as the garage area or basement depending on the plans. It’s common in larger homes to have a “safe room” under the porch as well for storage or tornado shelter. The only real concern with what you show in your picture is it is a possible new home for rodents.
Morning Aaron. Hope this post finds you well.
Aaron, put everything you observed in context.
Exterior: Lot - Walkway - Driveway - Lane - Path…
A: Observation: Walkway.
1: Soil loss. 2: Poor Walkway Drainage. Water should disperse to the street.
B: Observation: Poured Concrete Front Steps and Landing.
1: Prior repair at the bottom of the first step. Location: Left side. Poor workmanship.
2: Uneven riser height. First step is taller/higher than the remaining steps to the landing.
3: Exposed poured concrete staircase drainage aggregate.
Any images further back?
Gravel/aggregate is used as a base or foundation to prevent concrete from cracking and shifting.
As well at times gravel requires compaction.
First though the undisturbed soil base must be properly/adequately graded/sloped.
Gravel/aggregate is used for drainage. Bulk water drainage will follow the direction graded/sloped soil.
Bedsides water bring number one, aggregate is the second most sought after commodity in the world.
Hope that helps.
I think you have answered my question. I thought the stone always needed compacting and was concerned it was a missed step that would lead to issues in the near future. Thank you for the information.
I just grabbed this pic while dropping off radon gear. Returning tomorrow for actual inspection. Grading was definitely not negative around this area though.
I come across this scenario regularly. If I see one similar to this before it gets poured I will send you a picture. Hopefully today or Monday.
@mdurante Could you post the pic to this tread, It would be helpful to all.
I will indeed . Only had commercial jobs today so will go cruise some new subdivisions that I pass on the way home and see what I can come up with.
Okay, well these aren’t EXACTLY what I was referring too but it is pretty close.
D.R. Horton just uses umcompacted dirt instead of gravel.
This one is filled with pea gravel but doesn’t go all the way to the ground.
Full depth of basement porch area to be used as a safe room. Inner wall had a door blocked out in the forms.
Different houses but identical foundation set ups.
Hope this helps
Here you go Scott
Thank you for going out of your way and taking the pics
The soil surrounding a foundation should be backfill soil for the first 3’ feet. Impervious non expansive/non contractive soil.
Every time I see aggregate under porches, raised patios or deck, the narrative pervious material is used to describe a defective understanding and finishing of the a finish/ing grade process. Water goes through pervious material. The aggregate will also settle into the soil over time.
Pervious: adjective. admitting of passage or entrance; permeable : previous
Image of a recent inspection.
This is incredibly helpful of you.
So in my situation I’m picturing concrete pushing the gravel to the form during pour or gravel just wasn’t pulled away from the form creating an opening on the side and the gravel poured out after form removal. Poor workmanship. Sound about right?