I love working with clients to buy and sell homes. Only food is more important as shelter. It’s a privilege to be engaged in such a fundamental need. During the Vietnam War I lived at a fire base for months in a one of a row of “hooches” made of sand bags and old tank ammunition boxes full of dirt. I thought it was wonderful, all things considered, but it helps illustrate the range of possibilities in housing.
One of the really fascinating things about shelter is what a complex system a house and its components can be, all aimed at the better functioning and longer life of the home, whether large or small, whether less expensive or more expensive. Your home is built in the context of a climate and a geology, and indeed in the context of the local economy at the time it’s built, not to mention in the context of market requirements.
Take, for instance, the foundation. By definition, it is the basis of the whole structure of a home. The foundation may be a basement, a slab, a floating slab, or a crawl space. Up here in Massachusetts, most foundations are basements. This isn't just a matter of the local market. Because of the climate and the geology of our area, the ground freezes, melts, freezes again. Sometimes it's wet, sometimes dry. One of the results of all this is that the ground moves and heaves from season to season and from year to year. It the foundation doesn't go pretty deep – below the frost line (in our area an average of four feet) -- the house will heave along with the ground, causing excessive settlement, cracks and leaks in the walls, ceilings and in the foundation itself. So, basements.
A crawl space might do, but that means the pipes, conduits and wiring running through the crawl space will be exposed to damaging elements and temperatures. So in our area a crawl space needs to be insulated and, basically, enclosed.
The way to build a house that doesn't heave and settle in our area is to build it on solid rock. That's not that hard to find in our area, but it's rarely suitable to serve as a foundation for a home. I've only seen less than a handful of homes in the past twenty years that don't have a basement. One was on a slab on top of solid granite. The other had a fairly deep crawl space that was completely enclosed and felt pretty much like a really shallow basement.
Beyond the question of what kind of foundation is the question of what the foundation is made of. These days, it's normally poured concrete or maybe filled concrete blocks. But we have a lot of older homes as well. Many of the foundations are field stone, made of large rocks that may well have been dug out of the excavation for the foundation. These rocks are mortared together, may extend underground out from the structure itself, lending extra support. They might even be given a waterproofing coat to help seal off the moisture. Over time, as the mortar deteriorates, more humidity and even moisture may find its way in. This makes it more difficult and more expensive to finish off the basement to make additional living space below grade. I see a lot of fieldstone foundations in our area, although most of those are at least a century old. So they're common, and they require attention and maintenance.
Another older material for foundations is brick. I will sometimes see a fieldstone foundation with brick above the fieldstone. Brick has the same mortar issues as fieldstone and, additionally, is not as strong as fieldstone itself. Most of the homes I see with brick in the foundations go back to the 19th century, although it was used in some homes around the country later than that.
Over the past century, our foundations have largely been poured concrete or filled concrete blocks. They're strong and durable. They open the door to finishing the basement space as living area – although below grade space cannot be counted in the official Gross Living Area.
No matter the material, the gutters, drain pipes, underground drainage system, and grading of the land around the home play a vital role in the effectiveness, usability, and durability of the foundation.
When you're reviewing a home, whether to sell, buy, or simply maintain, you need to take a really good look at the foundation. Most of the homes in this area (and in the United States) are wood framed. A key part of those homes are the systems for moving water away from the structure to keep the wood dry. It's a simple goal with complex, interacting solutions. A good inspector is a must, but not cheap. Most of them, but not all of them, start in the basement and work their way up. Some start at the top and work their way down, probably on the theory that any foundation problems will be visible higher up so when the inspectors get to the basement they'll already be on the lookout for the problems whose symptoms they've already observed.
A house is a wonderful system designed to make your shelter effective, enduring, and pleasant. To make it a home. My sandbag and ammo box home in Vietnam was pretty simple, but even it had to survive a six-month monsoon.
If you want to know more about homes in our area, register on my website (upper right corner) and look over the homes for sale there. It might be a learning experience. If you have any questions, contact me. I'll be glad to try to help.
The foundation drawings are from Houses:The Illustrated Guide to Construction, Design & Systems by Henry S. Harrison, Real Estate Educational Company, 2nd Edition 1992, © Realtors National Marketing Institution