By Mike McClintock
Special to the Chicago Tribune
September 19, 2008
Throw enough money at a bare-bones basement and it can become a palace.
You can cut through concrete foundations and install walk-out window wells flooded with light. You can cut into concrete floors and plumb a full bath with what's aptly called an up-flush toilet. (Waste has to be pumped up to reach the sewer line.)
You could spend $125 a square foot for more room on the first floor. But with most household budgets kind of tight these days, let's take the straightforward, economical approach with guidelines for key steps, and too often missteps, of a full basement makeover.
Codes. The highest hurdle is often a fire code calling for a second means of egress, code parlance for another way out aside from the first-floor stairs. This fundamental provision isn't based on the wall opening you need to escape through, but on the opening needed by a fireman in full gear to get in and save you. Walk-out basements qualify. But a buried basement typically needs an escape window, or larger escape well. Check local codes, and you're likely to find that the sill of any escape unit can be no more than 44 inches off the floor. That's lower than most basement vent windows and requires cutting into the foundation. Then, several well designs qualify. For instance, deep corrugated wells can be fitted with code-approved ladders, while the Scapewel Window Well, (about $500 to $700 depending on size) made by The Bilco Co. (bilco.com) creates a walk-out well with terraced steps.
Waterproofing. Start with a dry space and your halfway home. If not, be prepared to weed through an array of proposals from waterproofing contractors—a lot of them bogus. Done right, basement waterproofing is an exterior operation; a barrier outside the foundation that sheds groundwater down to drains at the footing. Supposed solutions like pumping "special" compounds along the exterior wall aren't likely to work. There are also interior systems. But they're based on the shaky premise of letting the foundation leak, and then trying to drain the water.
If there's just one crack, scrape it out and fill the void with hydraulic cement. It also helps to grade dirt away from the foundation, and to extend downspouts so roof water can't drain back against the building. But durable waterproofing of porous basements usually includes excavation and layered applications outside the house.
Conditioning. To become finished living space, a bare basement needs the same quality of heating, cooling and ventilation that you have upstairs. That's not hard to accomplish in walk-out basements with full-size windows and at least one wall completely above ground. It's more complicated when the basement is buried except for a few vent windows near the ceiling. In a small basement, you may be able to tap existing heating and cooling plants to handle the extra load.
In a large basement, it's likely that equipment will have to be upgraded. In any case, you'll need an experienced contractor to reconfigure supply and return ducts so the new space isn't conditioned at the expense of the old. One of the best solutions is a zoned system with separate thermostats and duct controls for different areas of the house. This lets you program full-level conditioning when people use the new basement, and save energy when they're upstairs.
Extending the thermal envelope. Decorating aside, the final hurdle is to wrap the basement floors, walls and ceiling to make a thermal envelope—a boundary of insulation (plus a vapor barrier on walls) that meets modern energy codes. On walls, the old-fashioned standard of nailing up furring strips has some drawbacks. First, ¾-inch furring is often the worst lumber in the yard—so twisted that it's difficult to straighten and nail without splitting. And it doesn't supply much room for insulation, much less wires and pipes. Applying it also riddles the foundation with nail holes—not the greatest idea in a space you want to keep dry. Building 2-by-4 stud walls eats up a few extra inches of floor space, but solves all those problems.
On floors, anything is possible in a dry space, including hardwood laminates laid as a floating floor. But the economical no-brainer is carpet over padding. It cushions and insulates the concrete in one step.
On ceilings, the economical best bet is acoustic tile laid in a grid of supports. This suspended ceiling allows room for sound-deadening insulation, covers the tangle of pipes, ducts and wires, but still provides complete access to your mechanical systems.