Thanks for stopping by this week! If you recall last week, we talked at great length about crawlspaces, and the value of a properly conditioned space. Today, we can build on those principals concerning some of the most desirable space in the house, the basement! Further, we'll look at how a properly implemented investment, can not only ad security and comfort to your home and health, but pay off big in the event of a home sale.
So, basements are literally the beginning of your home, so we'll begin with its beginning- digging a hole. In that hole, will go a "footer" of concrete, similar to a thick, narrow sidewalk that supports the walls and ultimately the roof of the house. Most basements, have another step, the floor is poured after the footer and walls have been erected. This is easy construction, but there is one problem. Old and new concrete will never bond to each other.
So from the start, there is a fundamental flaw in the design of the basement, an area called the "cove." Basically, the cove is the space where the footer, wall, and floor meet in the basement. Now don't read too much into this, there is a lot of care and technology that go into making this joint as solid as possible, and it is well guarded from moisture.
You see on the outside of the footer, is placed a drainage tile that is encased in gravel, sometimes up to 2 feet thick. This presents a "path of least resistance" for water to escape to before getting to that cove joint. Usually the contractor will coat the outside of the wall with a tar-like material, and more rarely place rubberized sheeting to act as a moisture barrier. The latter is a great option, and usually isn't done unless specified due to cost. If all else fails, there's usually a sump pump built in to keep any other moisture at bay.
From this footer, the walls will be built or poured and usually measure between 8 and 10 inches thick. Most basements have a height between 7 and 8 feet, which is important to know, because there should be about a foot between the grade (ground for those of us without a hard hat on) and the start of whatever siding is on the side of the house- with few exceptions. This gap is left for ventilation and easy access to utilities.
Above the concrete block or just concrete wall is placed treated dimensional lumber (2x8, 2x10 usually) called the sill plate. On this plate, everything above is bolted, such as your floor joists, rim boards, and sub-flooring usually tongue and grooved OSB, or oriented strand board. And then the rest of the house.
With the construction of the basement foundation, barring any major concrete mishaps or acts of God, it should last as long as the house!
I have met homeowners that had the house built, the contractor declared bankruptcy before finishing the development to the end of the block, and then the whole neighborhood found out that none of the footers were established on properly prepared soil. Every house on their side of the street was 3 years old and had about $60,000 in foundation repair needed. Always do your due diligence from the foundation up!
Basement problems can be boiled down to settling and water. Settling will happen, and should be corrected early, when it is easier and cheaper. Settling happens slowly, so it does give you time to plan ahead. Water on the other hand, is liquid wrath that falls from the sky and seeps from below to assault your foundation while you sleep! Sure, that's dramatic, but the point is that the house is built in a pond.
Most homeowners never notice a problem with their basement, until they really DO notice—similar to when the cable goes out. It can also be very difficult to see issues early if the basement is finished. There can be subtle hints, some wet carpet in the middle of the floor, sagging floors on the first level, even increased allergies when you are playing foosball downstairs. Your best bet is to scrutinize the basement's condition once a year, or after big rains. Be as invasive as you want, but remember that basement problems never fix themselves. Prevention is cheap, correction is expensive.
This past summer we had 8" of rain in just a day- more water than we have ever had in recent memory. Suddenly, those little problems that have been hiding for a lot of folks started stacking up, and many had leaks and significant water. One of the main problems was overrun sump pumps. Sure with a rain like that you would expect that issue. How did that much water get into the basement in the first place though?
Remember that drainage tile by the footer- the one encased in gravel and then dirt? It's clogged with about 20 years of sediment and soil. Now from time to time you can pay some bucks to have the drain "flushed," but keep in mind that forcing water into the drain only forces all the clogging dirt to on spot. That can actually be worse. When this drain doesn't work, you will build "hydrostatic pressure."
Water always flows downhill, always follows the path of least resistance, and always levels itself out. This is the principle in hydraulic equipment like earth movers—the point is that when water levels itself, it applies pressure to things in the way, like your foundation.
Step one: Serve water a warrant!
There are a lot of ideas and ways to waterproof a basement. For the sake of time, I will share the best of these methods and let you make your own conclusions. It all comes down to where you DO want the water and where you DON'T want the water.
For starters, there are many coatings and paints that are promoted as "waterproofing" materials for the basement. Here's the thing, the material you are painting still has water in it. Think of it like this; you have a 1/16th thick coating of paint holding out a gallon of water (about 8 pounds per square inch) with an 8 inch running start through the wall. It just won't last, leave the paint for the shutters and fences!
The other idea is to put that coating or sheet material on the outside of the wall, and sure that's better way, but it comes at a cost. Excavation is costly in time and money. First, anything like prized rose bushes and air conditioners have to be moved for the dig—and then they cannot go back for a year! The soil has to settle again. The second is that once the wall is sealed and covered over, try finding someone that will warrant their work. A year tops!
Another approach is to work from the inside out, replacing the exterior drain with an interior drain. Basement Systems, based in Connecticut has a great solution called WaterGuard. It is an engineered draining system that is designed specifically to drain water from the wall, and cove of the basement to the crock or drain. Because it installed in the concrete itself, it cannot clog with dirt and mud, and it will relieve hydrostatic pressure completely if installed on all four walls. Not bad! Check out this video with Ron Hazelton on the installation.
Once you get the water piped to a drain or sump pit, you need a good pump!
In the world of sump pumps, the name to find is Zoeller. You are looking for an all cast-iron design, but bear in mind, that all pumps have a limited lifetime—due to the nature of their work. Even with regular cleanings, a top end model will last about 6-7 years. You want something that can drain about 2000 gallons of water an hour, and get this, it has to clear the 8 feet up the wall too.
When buying a pump, the person selling it to you should say "my pump will clear XXXX gallons of water, at an 8-foot head." The head they are referring to is the wall height. There are a number of good pumps on the market, and many have excellent backup systems in case the power fails. The best on the market now is the TripleSafe, again from the innovators at Basement Systems.
WaterGuard will keep water off the floor and greatly reduce the hydrostatic pressure, but for cracks in the wall you'll need to either inject it with epoxy or a polyurethane resin, or put in some other kind of secondary drainage system. That secondary can be tied into the WaterGuard system too, and from there you shouldn't need to worry about water unless animals come to your front door in pairs!
This is also a good time to look for bowing walls or structural issues.
Many times cracks are structural issues and water is only a factor in the settling of your foundation. The worst part about settling is that your once solid wall can become many large moving pieces. Now it's alright, but you will definitely need a professionals' help. Here is a primer on keeping your walls in good condition
There are many different ways to correct walls and foundations, but that is for another day. Just know that prevention is cheap, correction is expensive. Possible fixes would include: steel I-beams, carbon fiber straps, earth anchors, and helical piers.
With the WaterGuard installed, and a good sump pump installed, you will never have to worry about water again! That means you can finish that basement and increase the value of your home even more! Most investors look for about 70% return on a fully finished basement, but the real value is a dry basement! Basement Systems published this article a while back, but the information still holds true.
Next week, we'll talk more about the structural issues associated with basements, and what can be done about them. Merry Christmas and Happy Holidays to everyone, take care!