# Grading around foundation for keeping basement dry



## strategery (May 2, 2012)

I often hear about the importance of grading around the foundation in order to keep the basement dry. I have examined the perimeter of my house and it looks like the grading could be improved some. 

I went to one of the big box stores and asked them where I could get some clean fill dirt for this purpose and they looked at me like I was an alien. 

Is this the correct name for what I need? Where should I get it?


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## oldognewtrick (May 2, 2012)

Try going to your local nursery or look on Craigslist for fill dirt.


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## nealtw (May 2, 2012)

Landscaper supply or perhaps a local gravel pit could put you in touch with truck drivers that haul fill away from construction sites.
You want 6 to 8 inches of concrete showing on the foundation and if you have a basement, you want to have waterproffing on the concrete before you add fill.


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## strategery (May 2, 2012)

I don't have any waterproofing on there now but it's a 100 year old house


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## CallMeVilla (May 2, 2012)

Is your basement wet?

Grading is one element of the waterproofing process.  You want water to shed away from the perimeter of the foundation.  BUT (always a "big but") the old houses used simple parging on the foundation wall and (maybe) clay weeping tiles. Both are inadequate by modern standards.  To truly handle the water, you need to excavate all around the perimeter, parge, attach a plastic membrane, drill and nail plastic sheeting, install modern weeping tile (hose) connected to a good drain, then backfill.

Sometimes, I have seen an interior solution where the floor along the perimeter is jacked out and modern weeping tile is installed.  It is directed to a sump where it is pumped outside as needed.

Let us know what you decide to do.


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## strategery (May 3, 2012)

Yeah the basement is pretty damp. My dehumidifier keeps it dry at right about 50% humidity. I don't get any water on the floors but I think I would if that dehumidifier weren't keeping it dry down there.

I just cleaned my gutters recently (which I do twice a year), but I may need to replace them as they are getting kind of worn.

Other than replacing the gutters I don't know what to do other than adding some fill dirt. Should I call a landscaping company to help me with this?


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## nealtw (May 3, 2012)

I would start by talking to a foundation waterproofing company first. Your best bet is like Villa said in his posting.


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## strategery (May 3, 2012)

I've talked to 3 of them and they barely said anything about the outside they just told me that I need their inside French drain and sump pump. One of them also said that they won't even do that unless I replace the basement floor.


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## mudmixer (May 3, 2012)

The drain tile (interior or exterior) at the level of the bottom of the footings is the key since it collects the water and eliminates the pressure against the walls. Interior drain tile also reduces the hydrostatic pressure under the basement floor slab.

The soil around the foundation is a mixed bag. The surface ideally should direct the water away from the house foundation. If it is a heavy soil (fine grained or just dirt) that can hold the moisture against the foundation. If it is "rock" or clean well drained material, it will allow drainage down to the footings and hopefully to the drain tile system that will remove it and prevent any leakge as it is intended to do.

Dick


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## nealtw (May 3, 2012)

Was there a reason they didn't talk about the outside drain?


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## mudmixer (May 3, 2012)

neal -

I have no idea who "they" are.

Very often, the exterior drain tiles on existing structures are very costly or ineffective because of installation problems (patios, sidewalks, attached garages, steps and landscaping). If the basement is unfinished, it is a "piece of cake" to install interior drain tile at the level of the bottom of the footings, put in a sump and provide power and a means to pump out any water when required. An interior system also does a better job of reducing the upward hydrostatic force on the basement floor slab.

Obviously, both interior and exterior systems combined would be very cheap on new construction, but few contractors will include it as a standard of construction quality.

Dick


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## nealtw (May 3, 2012)

strategery said:


> I've talked to 3 of them and they barely said anything about the outside they just told me that I need their inside French drain and sump pump. One of them also said that they won't even do that unless I replace the basement floor.



Dick: "3 of them" are the "they" I was talking about. The problem is with alot of specialists is that they speciallize. If the three of them all specialize in interior drains that is what they will requemend. As you say the decks and driveways and landscape is a consideation but a specialist in outside drain may be able to solve that some of that. 
I do agree much can be said about pressure under the floor, after the floor broke in my dads house we lowered the drain tile to below the footing on the outside, I beleive that is where all drains should be.


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## strategery (May 4, 2012)

Good point, Neal.

I did talk to 3 basement waterproofing companies that all specialize in the interior or "negative" side I think it's called. 2 of them will perform the work and install a sump pump. 1 of them said the floor has to be replaced with it.

Also, I have talked to 3 different foundation replacement guys just to get their opinions. All of them said that the job is worth doing if I'm willing to invest the money. 2 of them are CMU guys but will do extra stuff like adding foamboard insulation on the outside and inside. 1 of them (the most expensive) only works with ICF but he's got a solid reputation. 

The cost of a complete foundation replacement is pretty expensive. They would have to hire a house mover to life the house and hold it up so the existing foundation can be demolished, hauled away, and new foundation can be built. The ICF route costs twice what the CMU would cost but if I were going to proceed with this I would still consider it because of all of the benefits.

Also, 2 of the foundation guys told me that I don't have to replace the whole thing at once. I could simply replace a couple walls and wait to replace the other two and the floor when I'm ready. I'm a little leary however about the quality that I'd get going that route.

But as it is, replacing the foundation is almost near the cost of getting an excavator and trenching and waterproofing the outside of what I have now (which is an inferior foundation, I think).


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## nealtw (May 4, 2012)

I don't get it, to replace the foundation they have to dig around the house and probibly break the floor, so they are doing the work of both inside drain and outside drain and throw in the foundation too. The extra will be when they decouver the footing has to be upgraded too.
How bad is the foundation or what is wrong with it besides leaking?  How much of it is below ground level? Is it concrete or what?
Raising a house can get expensive, I would have no problem just replacing the parts that are bad.


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## strategery (May 4, 2012)

There is no footing with this foundation. Terra cotta block. Walls have bowed in some. An inch to an inch and a half.


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## nealtw (May 4, 2012)

Terra cotta block; is not something I have seen but it does sounds like repairs or replacement.  Adding fill to the landscape or just looking at drainage I think would be silly, you need to look at all of it.


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