Hi all. I seek guidance from the wise. I’m a first-time homeowner. My wife and I were outside laying mulch. Planted at the corner of the South side of the house are several large rhododendrons. The prior homeowners rarely (if ever) did any yard work, so I was rooting around behind the rhodys triming them and raking away a 2-inch layer of leaves resting against the house’s foundation. As I raked away the leaves, I noticed a depression of soil right at the foundation. So I got on my hands and knees and starting peeling back the soil to inspect. Suddenly, the entire soil gave way and I discovered a bunch of deep holes going down along the foundation. Mixed in with these holes are several large rocks, so the whole thing appears to be a network of rocks and caves. This sounds larger than it is, as the hole is only about a foot deep, maybe a foot long and only about 4 inches wide. This “network” is situated on the outside on the downstairs fireplace which our cats are always sitting in front of, and now I think I know why they sit there. I think mice are running around inside this network of caves, as I found a poison mousetrap about 5 feet away, under the screened-in porch. So my question is this: how do I fill this in, and what should I use to fill it in with? I’m in MA, so we’re got frost-line issues here. Should I just throw dirt in there, or some kind of gravel, or a mixture of both?
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Let me be the first to welcome you in.
just pour sand over the carelessly done backfill and run the garden hose over it. The water will wash the sand down into the cavities. A finer silt soil is likely to cloud up you perimeter drain system.
Excellence is its own reward!
Think it's possible he found the building's construction dumpster?
I think I already found the dumpster inside the house! We had to pull-up a few of the lower step's stair treads, and what a mess we found underneath. All sorts of wrappers, and packages from electric recepticles, and there was some newspaper from the 1950's (when the house was built).
Ouch! You might want to, then again you might not want to, dig into what you found outside. If it's a construction dumpster, ie mini land fill, there's a host of headaches sitting there.
Critter / vermin habitat, drainage problems, frost heave dilemmas, a host of other odds and ends. Does be safe or sorry apply here.
Welcome to BT weareaubc. Enjoy.
Sounds like there is a lot buried there. Used to be way more common back then to backfill with job junk. Best leave sleeping dogs lie and fill it with sand..
Excellence is its own reward!
"Bumped" into a couple of "sites". Oh the worms....
Yur right. Wash in sand...
Thanks for the welcome everyone!
I think I'm beginning to understand what has happened, and it appears that Qtrmeg is right on the money regarding the fine soil washing away (and I am super curious as to where it goes). About 5 feet to the right of my foundation problem is a screened-in porch which extends out from the house about 8 feet. Anyway, at the two corners, furthest from the house, are downspouts from the gutters. And guess where these drain? Straight down into the ground. No downspout extensions or splashblocks to divert the water. So, although the front and side yards slope downward toward the street, I'm thinking that some of this water must travel along the house on it's way to the front yard, and eventually the street, slowly taking away the finer soil particles, leaving behind a network of hollows.
I dumped in a 50lb bag of sand after work today, and I ran the hose into it watching it wash down into the hollows. That seemed to have worked, but now it looks like I'll have to do some gutter work. Should I just run downspout extensions a few feet away from the house?
Thanks Piffin! I'll give that a try tomorrow.
It could be this area is a low spot where surface water has washed the fines of the soil away, (you don't want to know where), and you should fill it as described above. It is possible the rocks are solid fill the previous homeowners used to fill the sinkhole. I really doubt anyone in their right mind would backfill with rubble.
If/when you get this filled, you should build it up to drain water away from the foundation, and "cap" the area with a soil more closely resembling clay, or some solid paver installed over the soil profile, out past the dripline.
"I really doubt anyone in their right mind would backfill with rubble."
You've never known any crazy builders, have you?
;)
Maybe it's just my bad luck, but in digging out to repair drainage problems, I've found at least three jobs where the builder had used the overdig in the excavation for a disposal pit. Sure makes it hard to xelan out a hole when it's full of 2x4s and banding strapps and off cuts from the shingles..
Excellence is its own reward!
I don't know any builders that aren't crazy.
I can only think of three jobs that weren't bf'd before we framed, and even then we didn't make a point to landfill. Hey, I grew up on the termite band, and it just wasn't done.
By rubble, I meant boney fill, you have to be a superhero to bf with bones and not tweek green crete. That is why I thought this might be retrobones.
In any case, fill and grade...fill and grade...fill and grade.
It was common practice up until the early 70's to have an on "site dumster"
Because of the "things" that got buried it was clamped down on. The owners or generators of these sites were heavely fined and made to remove them.When there is no one watching it still happens today. It was common practice to doze a structure into the basement and cover it over in the 40's 50's and 60's.