I think you REALLY need professional advice on this one - what might seem totally obvious to you may be totally wrong for various reasons you can't guess at. BTW... "So, it's dirt and I'm certain that the foundation back there goes all the way down. In fact, I'm pretty sure it doesn't." What??

Sorry! That's supposed to be, "So it's dirt and I'm NOT certain that the foundation back there goes all the way down. In fact, I'm pretty sure it doesn't.

Now, while I intend to get professional advice, my experience on this project has been that competence in professional advice is hit or miss. There's nothing like hitting folks who've been there for their accumulated knowledge.

FWIW, my professional advice thus far has been, "Just clean it out, cover it with plastic and leave it."

I'm looking for more info as I have an opportunity here, one time only. Things are about to start happening fast on this project, so if I want to exploit the opportunity of having the floor up, it has to be like in the next 10-days.

Mark

Here is a link that might be useful: Our Project, RehabOrDie.com

You need to be very careful about removing dirt in partial basements, especially on older houses.
There may not be actual footers under the wall, and digging even close to the wall can cause shifting of the earth under the wall load.
A geotechnical engineer can look over the building and the soil and make recommendations.
A lot depends on the soil type under the foundation.

Mark,
I don't know where your house is, but in central VA most of the brick houses of that era have English basements, but no footings. There is one across the street from 1862 that has a partial basement but I don't know the particulars - possibly built cheaper because of the Civil War. I'd be very careful about digging around/under the walls. I've known several instances where walls collapsed because of digging around the base.

You need a professional engineer who knows (and appreciates) old houses to advise you about digging in partial basements - especially basments with recently unsually wet soil. Call you local historical society or your State Historic Preservation Office (SHPO - every state has one, I believe, and they can start you in the right direction) to get names of people who fit my description. It's quite important to get someone with old house experience and affection. Houses without full foundations (i.e.with footings) are completely dependant on undisturbed soil for stability. Even a ground hog burrow can create problems. Bad things can happen under those circumstances, so get someone with an engineering license in there to help you decide what to do. I would think this is particularly important in brick houses (vs interconnected wooden hulks like my timber-frame structure.)

And, yes, you should put down some vapor barrier while you're at it. It is easier to do with the floor open, but it can be done later, even if you have to practically push the material forward with your nose as you slither along in the crawl space. BTW, there are materials that are better for vapor blocking than contractor's poly. I can make some suggestions if you need them.

HTH,

Molly

Molly,

I'm up for suggestions on the vapor barrier, which I have to put down regardless.

Just to clarify--the "hole is dug" so to speak. I don't want to dig anything at all. I just want to make sure that things are stable so I don't have to worry about it. So, if it's cheaper to stabilize that foundation now (and no matter what, it would be) and I SHOULD do it, then I want to. Cement is cheap, right?

At this point, all of the foundation is supported and drainage is decent (up from bad) and getting better. I'm just worried about a few areas (a couple feet here and a couple feet there) where I don't have a full 2' of loam up against it.

If anyone is curious, and perhaps has dealt with this in a similar context, this is urban Ky, there's cement on 3 sides and brick on one at grade. The soil is clay and loam, mostly the latter. Not much sand.

M

Here is a link that might be useful: RehabOrDie--our blog

Even placing a vapor barrier can change the weight bearing characteristics of the soil by keeping the soil itself damper.

In a number of cases I have worked on the geotechnical engineering recommendation was to insulate the underside of the floor and place the vapor barrier there, keeping the dirt completely uncovered and the space well ventilated.

I'm not at all surprised that a vapor barrier could change the weight bearing characteristics.

This takes us back to an idea that my wife had, which is at odds with what the HVAC guy recommended. She wanted to spray the bottom of the floor with closed cell foam, he wanted to spray the the walls and where the joist meets the foundation and use a vapor barrier and condition the entire basement.

During the summer time, humidity is a big issue, and we know radon to be one around here too.

Mark

Hello! This was 11 years ago, but just came across your post looking for advice regarding the exact same issue. What did you eventually decide to do?

I am about to decommission a 1.25m X 5.0m half below ground level cellar under my timber floor. It has up to 100mm deep water seep in during winter months and the concrete block walls are slowly collapsing inwards. My plan is to knock a couple of holes in the concrete floor, fill with 20 minus crushed concrete and compact over a couple of months. This should fill the base and not allow water to reach the surface. Once I prove off having fixed the water ingress I will fill to normal ground level with high content clay soil and compact. Once stabilized I will have the floor blocked up to level. Does that help Ktktw? or what was your solution. Simo