Basement Water Intrusion, Foundation Concerns. Please Help!

[MustbeDIYer]

My house is on the side of a hill that slopes downward toward my backyard. In other words, my backyard is at a higher elevation than my front yard. El Nino is here and water is intruding into my basement. There is roughly a ten foot drop in elevation between the back wall of my house and the bottom of a concrete stairwell that leads from the the living area to the basement. I can see water flowing in through cracks in the bottom three steps. The stairwell begins about 6 feet from the back wall and ends in the basement about 12 feet from the back wall. There are two retaining walls that extend from each side of the front of the stairwell parallel to the back wall all the way to the foundation on the sides of the house. There is a crawl space between the retaining walls and the foundation under the back of the house. I just crawled down there and found a small stream of water flowing between the foundation slab and the wood into the crawlspace. This is happening only in one corner. There are also large damp water spots in several areas on the surface of the crawlspace dirt. When pushing the dirt down in these areas they fill up with water.

It seems to me that both surface water as well as groundwater being fed by recent rains which don't seem to end are causing the intrusion. I'm looking for a way to mitigate this intrusion as much as possible in the short term and then a longer term solution. The house has been here for over 100 years. Any ideas? I don't think a simple french drain adjacent to my foundation would work, as I'm pretty sure the water coming from below the foundation is contributing to the intrusion. I was thinking about building a ten foot deep trench around the house and filling it several layers of flexible drainage tubing and pea gravel, essentially a wall of a french drain. I'm concerned that this might lead to foundation instability though. Does anyone have any expertise in this area? I'm looking for a low cost solution and have virtually no experience dealing with issues such as these. This is my first house and I purchased it less than a year ago.

 

[GrandpaDan]

If I'm picturing it right, you want to build an intercept trench, filled with crushed rock and drain tile, to divert the water around the house foundation? You have enough slope to run the drain tubing downhill and away from the house? I don't think you need to go 10 feet deep, if you got rid of most surface runoff, diverting the rain from around the house, including what comes off the roof with gutters and downspouts, you will probably solve the problem.
As long as you don't undermine the foundation footings, you should have no problems with the structure.

 

[dovetail]

To be completely honest this is not a diy project. Grandpadan's suggestion of rerouting the down spouts is probably as much as you want to tackle. Other options that might work include regrading the yard (in most jurisdictions this will require a permit) and incorporating burms and swells to redirect water. This method will require guidance from a landscape architect or engineer. Waterproofing the foundation walls and installing drainage lines at the base of the foundation is another option but this will require an experienced contractor that specializes in foundation waterproofing work. It requires equipment and good operators to dig it out without damaging the foundation, shoring walls to protect workers in the trenches, and in some cases may require bracing to support the foundation. Homes the age of yours generally have stacked footings which are easily compromised. Another option is to open up a 1' trench under the slab, install drainage pipes, and run those to a sump pump that will move the water out. If your problem is ground water working its way up this may be necessary on top of the other work. Again this requires knowledge, bracing, and understanding of older home foundations. Unfortunately as I said earlier none of the real repairs are diy and all will involve an engineer.

 

[GrandpaDan]

When you say the small stream of water is coming in between the "foundation slab and the wood into the crawl space"...do you mean to say that the outside surface water is so high it flows in between the foundation and the wood sill sitting on it?
If that is the case, the grade outside is way too high next to the house...the surface should always pitch away from the house at least a few feet...don't make it easy for surface water to intrude.

What is a "stacked" footing? Dovetail?

 

[dovetail]

A footing that consists of brick or rock flared out at the bottom and decreasing in size as it comes up to form the foundation wall. They can be as large as eight courses (width) at the base of the footing and where they start to form the foundation wall usually go down to 2-3. They can be extremely unstable depending on a variety factors such as soil type, water intrusion, quality of the material used to form them, mortar quality, and so on.

 

[GrandpaDan]

The force of a foundation spreads at a 45 degree angle underneath it. This does not vary much, regardless of soil conditions. Overly saturated soil can act much more fluid, though.
I don't think anything close to a 10' trench is needed...it sounds much more like surface runoff. When the house was originally built, that hill was there, and they didn't ignore it...those old builders paid attention to such things, and by the fact it has done ok for 100 years is testament to that. But I suspect that over the years, the hill has been slowly migrating down and piling up against the back of the house, when originally the back was built so the top of the foundation wall was well above the grade, and water was diverted around the house by berms and swales. They used design to avoid the problems, not work-arounds like sump pumps.
Do you have enough slope on your whole lot that if you intercepted the surface runoff with a trench and drain tile, you could run the discharge around to the downhill side and away from the house?

What you can do yourself or can't do yourself is for you to judge, nobody else knows you well enough to determine that for you.

 

[dovetail]

GrandpaDan,
Soil condition and type actually play a big factor in how a footing must be engineered, constructed, and installed. Anyone who has worked on commercial or government projects will verify that for you. Depending on how many stories the structure is, soil type, and plasticity of the soil building departments and engineers will mandate different methods and materials.In most cases the standard method of excavating until you reach soil that has at least 90% compaction, forming, reinforcing, and placing the concrete is suitable, that isn't always the case and having to have footlings engineered does happen with some frequency even in residential construction. I wouldn't be so confident in what old time builders did and didn't pay attention to. If you study the industry and the history of construction you will find speed and money has always been a priority in the construction of homes. We are actually much better at considering the many different aspects and how they effect different elements of the home and environment today then they were back then.

The sump pump suggestion was for if the op was having ground water intrusion issues from an underground spring. This is a fairly common occurrence and the sump pump is the standard way to deal with it.

If the op is in the states a land disturbing permit will be needed in most jurisdictions for the regrade. The building department will require a licensed engineer to do the plans. Failure to get the appropriate permits can result in the building department fining the op as well as liability for damages caused to other structures and or land. Unless the op is an experienced operator it is doubtful they will have the skills necessary to do the work. Having done projects like this and operated heavy equipment I can tell you there is a lot more to it than just pushing some dirt around. The same can be said for the foundation water proofing. There are some projects which are just out of reach for diy unless the person doing the diy has experience in it or it is an area of expertise. The OP has stated they do not have experience in this area and it is their first home. While I'm fine with encouraging people to take on projects around their house I would consider it irresponsible to encourage someone with no experience to take on a project that can give seasoned pros problems.

 

[GrandpaDan]

Let's define the issue here.
The OP isn't sure where it is coming from, but everything points to surface runoff and drainage. I've asked questions to get detail so I can help him further, because I do not believe this is a big deal, and if it is not a big deal, a DIY guy with any brains and skills can handle it. Throwing the scare into people as a first step is something a contractor does to get business. The OP might be able to fix it with two hours work with a good shovel, if we really understand what is happening. Don't make it outside the reach of a DIY if it does not need to be.
He does not say there is a "spring"...he says there is a stream of water coming in. If it was a "spring" any fool with a good finger could stick it in and tell by how cold it is.

 

[dovetail]

I think, you think you know more than you do. Underground springs can push water up under a slab, water intrusion to the top can occur around the perimeter or through any cracks in the concrete. I'm not a contractor but I am a professional with a lot of experience. I'm trying to be responsible with my answers, not scare anybody. Obviously if you look at some of my answers I try to offer advice to help that will not get anybody hurt or in over their heads. The building industry is getting more complicated everyday, while there may be some diyers out there that can handle complex projects most can not. Those that can will not be on an online forum asking for answers. I diy many projects around my own house so obviously I'm not against diy. Even with my experience I know when it is not reasonable for me to undertake a project whether that's due to it being outside my areas of expertise or simply not cost effective for me to diy. Again regardless of whether the OP intends to diy or not the advice of an engineer who can see the problem should be sought. There are a lot of variables to be considered and without physically seeing whats going on no one can accurately diagnose the problem. At any length we are both getting off topic and I apologize to the OP and yourself for that. I've stated my opinion on the matter and will now bow out.

 

[GrandpaDan]

The industry is hardly any different now than it was decades ago. Housing is far behind commercial construction, and commercial construction is not substantially different either .Details change, but the core is the same. In 1850 George Washington Snow invented the "balloon frame", and other than small changes to reflect changes in available timber, Balloon framing gave way to Western platform framing, rafter to trusses, plaster and lath to drywall, knob and tube to Romex, galvanized water lines to Pex, cast iron bell and hub waste to PVC.
If computers had advanced at the same rate, the one I'm using right now would fill a double wide trailer. If we built cars the same way as houses...don't get me started.

We could have a faceoff on experience, seeing as you say I think I know more than I do. I know what I know. I know what I don't know, too. My opinion is based on 50 years of construction experience, at all levels. My last project was for the VA, and was worth 13 million. I supervised all construction and managed all the contracts, including those of the A/E. In my spare time, I've completely renovated and restored 3 100+ year old homes that I owned. I've run my own businesses several times, worked on homebuilding crews, driven dump truck and ran the backhoe, the total dollar volume of my career would be around 120 million worth of finished construction.

I don't like posting credentials to back up my point of view, because I prefer thing to stand alone...make sense without anything to bolster it. My feeling is that the truth is the truth, no matter who says it.

I'm retired now. I've always been a DIY person, and I encourage anyone to do the same. It's not magic, it's not rocket science and the problems are very often much smaller and easier to deal with than they might appear. Fear of the unknown magnifies the danger. Take the OPs' foundation...on a stick built house, you could take 3 feet of foundation out from under the sill of a single story section, and probably get no measurable settling, because the wall acts as a beam...it's not like a brick wall, where it is mostly compression, and if you lose support at the bottom, the whole stack can drop.

 

[dovetail]

The industry has changed exponentially from where it was 12 years ago much less decades ago. We build homes that can be controlled (electrical, low volt, plumbing, hvac, doors, security systems, and so on) from anywhere in the world from a cell phone. We build structures that can withstand a direct hit from an F4 tornado and suffer only cosmetic damage. We build homes and structures which are 100's of times more efficient than even twenty years ago. We are able to use diodes for lighting (not feasible ten years ago). We have developed engineered structural components that far exceed what was used decades ago.Building codes have become stricter and more comprehensive. The infrastructure has become more complex in design as well as more efficient due to changes in technology. Projects that could not be constructed 20 years ago are being constructed now due to changes in material, processes, equipment, and skill (read specialized trade labor).

The way structures are constructed directly coincides with what environmental factors the structure must contend with and codes reflect this as well. Preservatives have changed, adhesives have changed, fasteners have changed, new tools and hardware are constantly being created to meet the growing demands of the industry. Environmental impact of structures is way more scrutinized today than ever in the history of the industry. Processes have changed; the industry has become faster and the workmanship better (contrary to popular belief), and safety practices have dramatically improved since I started in the business.

The tools and equipment used to complete projects has grown evermore efficient and technical. Modern heavy equipment can be tied to a computer and satellite which will then dig to exact percentage of grade removing human error from the equation. Homes can be built in a factory and installed onsite in mere hours (Modular, and these aren't the glorified trailers sold as modular in the 70's). Those same homes according to FEMA way exceed the performance of traditional stick built homes in hurricane settings.

I've been in this industry a long time as well, I've grown with the industry and worked in multiple facets of construction. I have in the past run my own company as well as worked for and run projects for large national companies and small companies. I've been in charge of many large projects as well as thousands of small projects and in my time of doing strictly infrastructure work alone may have eclipsed your total volume worth of finished construction. I've built homes, remodeled homes, worked on historic restoration projects, hospitals, commercial buildings, government projects, state projects and so on. As far as equipment I've operated everything from mini excavators and skid steers to loaders, back hoes, full size excavators, rollers, dozers, etc.

I'm not retired and still very much in the mix of the industry. I have already stated I have no issue with DIY and if I did I wouldn't bother offering any advice to people on the subject. I have serious issues with people trying to tackle projects they do not have the skills and knowledge required to complete safely and competently. There are multiple reasons why some projects require bringing in professionals. If you truly have the background you claim to have you understand that. Public safety and property damage due to negligent actions is a big concern in the industry as reflected by the constant tightening of rules and regulations instituted by federal, state, and local governments, insurance companies, and contractors themselves. You would be surprised how many potentially devastating mistakes are made by well intending people trying to perform work they are not qualified to do. You don't have to look any farther than your deck for an example of this. The fact that 244'000 people a year are injured in decks collapses should be enough proof of that. Do you know what the most often diy'd structural project is? Decks. That's not to say all diyer's can't build decks as I have seen some beautiful well built diy decks. Not everyone has the skill, knowledge, and technical proficiency to build them or tackle every project thay would like to. Same as not everybody has the skill, knowledge, and technical proficiency to perform surgery. Telling someone they can tackle and DIY any project is irresponsible. That is not the case by any stretch of the imagination. Encouraging people to build their skills over time, research how to successfully complete them, and work up to larger complicated projects as their skill and knowledge accumulates is responsible.

 

[GrandpaDan]

The industry has changed exponentially from where it was 12 years ago much less decades ago. We build homes that can be controlled (electrical, low volt, plumbing, hvac, doors, security systems, and so on) from anywhere in the world from a cell phone. We build structures that can withstand a direct hit from an F4 tornado and suffer only cosmetic damage. We build homes and structures which are 100's of times more efficient than even twenty years ago. We are able to use diodes for lighting (not feasible ten years ago). We have developed engineered structural components that far exceed what was used decades ago.Building codes have become stricter and more comprehensive. The infrastructure has become more complex in design as well as more efficient due to changes in technology. Projects that could not be constructed 20 years ago are being constructed now due to changes in material, processes, equipment, and skill (read specialized trade labor).

The way structures are constructed directly coincides with what environmental factors the structure must contend with and codes reflect this as well. Preservatives have changed, adhesives have changed, fasteners have changed, new tools and hardware are constantly being created to meet the growing demands of the industry. Environmental impact of structures is way more scrutinized today than ever in the history of the industry. Processes have changed; the industry has become faster and the workmanship better (contrary to popular belief), and safety practices have dramatically improved since I started in the business.

The tools and equipment used to complete projects has grown evermore efficient and technical. Modern heavy equipment can be tied to a computer and satellite which will then dig to exact percentage of grade removing human error from the equation. Homes can be built in a factory and installed onsite in mere hours (Modular, and these aren't the glorified trailers sold as modular in the 70's). Those same homes according to FEMA way exceed the performance of traditional stick built homes in hurricane settings.

I've been in this industry a long time as well, I've grown with the industry and worked in multiple facets of construction. I have in the past run my own company as well as worked for and run projects for large national companies and small companies. I've been in charge of many large projects as well as thousands of small projects and in my time of doing strictly infrastructure work alone may have eclipsed your total volume worth of finished construction. I've built homes, remodeled homes, worked on historic restoration projects, hospitals, commercial buildings, government projects, state projects and so on. As far as equipment I've operated everything from mini excavators and skid steers to loaders, back hoes, full size excavators, rollers, dozers, etc.

I'm not retired and still very much in the mix of the industry. I have already stated I have no issue with DIY and if I did I wouldn't bother offering any advice to people on the subject. I have serious issues with people trying to tackle projects they do not have the skills and knowledge required to complete safely and competently. There are multiple reasons why some projects require bringing in professionals. If you truly have the background you claim to have you understand that. Public safety and property damage due to negligent actions is a big concern in the industry as reflected by the constant tightening of rules and regulations instituted by federal, state, and local governments, insurance companies, and contractors themselves. You would be surprised how many potentially devastating mistakes are made by well intending people trying to perform work they are not qualified to do. You don't have to look any farther than your deck for an example of this. The fact that 244'000 people a year are injured in decks collapses should be enough proof of that. Do you know what the most often diy'd structural project is? Decks. That's not to say all diyer's can't build decks as I have seen some beautiful well built diy decks. Not everyone has the skill, knowledge, and technical proficiency to build them or tackle every project thay would like to. Same as not everybody has the skill, knowledge, and technical proficiency to perform surgery. Telling someone they can tackle and DIY any project is irresponsible. That is not the case by any stretch of the imagination. Encouraging people to build their skills over time, research how to successfully complete them, and work up to larger complicated projects as their skill and knowledge accumulates is responsible.

 

[GrandpaDan]

No, they have changed incrementally, mostly on the peripherals.
Most houses are a prototype, with a production run of 1.

Imagine building cars with the same process.

 

[dovetail]

"The force of a foundation spreads at a 45 degree angle underneath it. This does not vary much, regardless of soil conditions. Overly saturated soil can act much more fluid, though."

This is theoretical in nature, in actuality the force spreads in a bulb like manner. Soil type and condition plays a big part in how load is distributed as well as the type and width of footing used. Excavation techniques can also effect the amount of settling and compromise foundation walls. The soil disturbed by the teeth on a bucket can account for a 1/2" of settling within a couple of weeks if proper tamping procedures are not used. May not sound like much, but this can cause substantial damage. Water movement through the soil can erode both the footing as well as create voids under footers which reduce bearing strength.

 

[GrandpaDan]

Use as much precision as you need for the work, but no more. Take out your straightedge, and lay it from the base to the load to the outside of the bubble, and a 45 degree angle is a pretty good match.

What bothers me is that the guy with the runoff problem almost certainly could have fixed his problem with attention to grade and drainage, without needing anything approaching what he originally suggested. Instead of looking closer at the source, and finding out what the real problem is, he probably got scared of dire warnings about things he didn't even need to consider yet, because he hadn't fully looked at the problem.