Recently I had some friends that were starting to shop for their first home. They are very smart folks, and started making a few criteria for their search-soliciting help on Facebook. One of their questions was what style of foundation would be the most beneficial. As I work in the home improvement industry, I wanted to give them the best answer I could. This is a continuation of that conversation, on what needs to be done for the best lasting investment.
Slab-on-grade foundations are a mainstay for homes built in warmer climates and tract/ investment home properties. There are many styles of "slab" foundations, but here in NW Ohio, they should be built with a "footer" of concrete under the frost line in the soil, and then a formed slab of concrete poured over that and anchored. This process is easy to do, and is possibly the best strength-to-cost ratio you can have. In our area many of the brick homes were built this way to save on building costs.
There are some drawbacks for slabs however, the largest being efficiency. Most homeowners find the winters in our area a little cooler with a slab, and many go to great lengths to make the floors warmer, either with extra rugs, or elaborate flooring options like hydraulic radiant heat. Plus, if the home has electric baseboard heating- just think about that heating unit being by a window that never really closes. There is money out the window.
Another drawback is the hard floor itself; while it supports the brick walls very well, it can be hard on your joints and back over the long haul. Last, if the slab was customized and has copper plumbing in the concrete itself, there can be a special set of problems! Concrete and copper have some adverse chemical reactions over time, and can crop up in the form of lost water pressure, or even spot leaks in carpeting or dampness on the floors.
The worst part about a slab is this; it cannot be improved, only repaired. That really hinders any investment opportunity.
Crawlspaces offer a happy medium for many homeowners who may want more energy efficiency, more adaptability, or even more storage out of their homes. The foundation starts in much the same way as a slab, with a footer. The footer is then built onto with a low rising wall of various materials such as block, flagstone, or in rare cases structural terra cotta. These shallow walls are usually vented with 8" x 16" sliding vents of metal or plastic. The main reason to use a crawlspace instead of a full basement is usually cost efficiency, and sometimes to level out a grade if there are a lot of hills on the plot of land where a slab is not feasible.
Advantages to the crawlspace have to have a few things to be a grand slam however! First, in order to have an energy efficient home you need to start with air flow. All homes "breathe" or circulate air from the foundation up, this phenomenon is called the "stack effect". It basically means that air flows up and out as it is warmed in a home creating a vacuum from the lower levels to the attic. So if this air is already moist and cold, the furnace will need to work twice as hard to heat the same air. Not very efficient, AND, more expensive!
The water heater doesn't get off the hook either! If there are pipes in the crawlspace that are uninsulated and exposed to the drafts typical in the winter, the shower isn't going to be as warm as you remember it being in the summer either. So step 1 is to eliminate the outside air.
Now, what about the floor of a crawlspace? Well, if you have one that's a start! Over the years I've seen crawlspaces with everything from dirt and gravel to other things that pass for "organic materials." Sometimes contractors will place a sheet of plastic down to act as a moisture barrier, and that's a good start. You see, the earth itself contains moisture, and can still create a moist environment- vented or not. Right next to those wooden 2 x 8's that are supporting your floors…
You guessed it, over time joists and flooring can mold and rot, giving your home a little more spring in its step. Of course you wouldn't want to venture down there very often, certainly not store anything of value. The other bummer is that anything that is metal can rust.
So, now we have to keep the air out AND keep the moisture out too? Smart money says yes!
The University of Washington Extension Energy Program concluded that entirely sealing of a crawl space is the best way to go to combat a host of issues, namely mold and pests affecting asthmatics and allergy sufferers. They even created a fact sheet for the H.E.L.P. for Kids initiative, sponsored by the Environmental Protection Agency. Check it out! http://www.energy.wsu.edu/Documents/crawlspace.pdf
According to the Energy Star Program, next to attic improvements, the basement and crawlspace are the best opportunity to increase the energy efficiency of your home, even out-performing window and door upgrades! Some estimates place the savings up to 20% annually, depending on what is done. Here is the side-by-side comparison:
One effective way of accomplishing these items all at once without a major intrusive job is encapsulation. This process varies by contractor, but the basic idea is the same. The vents are closed and blocked with foam of some kind for insulation. The rim joist (the space between the joist on the perimeter of the home) can also fluctuate in temperature with weather, so foam can be applied here too as a nice touch. Then the entire crawlspace is layered in a moisture blocking substance usually looking like a swimming pool liner. Sometimes it's merely plastic sheeting that is several mills thick. The walls, piers, and any other structure touching the ground are layered over with the material and then sealed off to prevent moisture, mold, critters, and bugs from entering the space entirely. Now your crawlspace is a cleanspace!
The last measure of course, now that we have this perfect "empty swimming pool" in our foundation structure is what happens if there is additional moisture in the future. The best laid plans can be set on edge quickly with a good waterspout, or sudden plumbing accident. Well, if you have a good contractor, they will insist that you look at a solid sump pump in conjunction with the encapsulation. Really, you should think of this as standard equipment any way, every foundation should have a way to manage moisture. Depending on your needs, a dehumidifier might be justified. I can think of a musician that had a sizable guitar collection, and ended up storing about 15 instruments in his new crawlspace. You can do that with a properly conditioned crawlspace!
Neat, sounds expensive…
It sure can be, but this is one improvement where you get what you pay for and more! In addition to the benefits of a clean crawlspace for yourself, the resale value can be significant. According to this article in Realty Times, some appraisers can value a properly conditioned crawlspace up to $20.00 a square foot. In that article they also mention some of the cutting edge materials you may want be familiar with.
More than that, the space is desirable to many homebuyers with a budget. These foundations are very versatile, and can be profitable!
In looking for the contractors, especially in this space, you should look for a couple of key things. Now, you are all smart people, so you know about the reputation of the company, BBB rating, and all that jazz - but who can warrant their work?
Most companies will offer limited workmanship warranties for a year, max! What? There is a litany of reasons why, and of course no one can predict, much less guarantee their work against an act of God. But still, seriously? One better, is a warranty that must be upheld with a "maintenance fee!"
Your best bet is to find a contractor that specializes in the work you're doing - after all you wouldn't have an electrician help you out on that clogged drain!
And really, do your homework on what those contractors are using in your project! Are the materials made for the purpose, or did they just buy the stuff at Box Depot on their way to your house? Good contractors welcome your questions, and want you to have full knowledge of what they are doing. Further, they'll be there if something unexpected comes up.
Today, we talked about slab-on-grade foundations, and crawlspaces from a purchasing value perspective. And we explored a little about how a crawlspace can be made into a great asset for a home if you do the right things. Next week, we will tackle the topic of basement ownership 101, waterproofing!