Top 5 DIY code violations according to building inspectors

Usually, they're really nice guys. So why does your stomach knot when the building inspector arrives to check your remodel? Because it is like a visit to the dentist -- you just don't know what unpleasantness he might discover.

Inspectors don't mean to cause anguish; they don't mean to extend your project past your wife's drop-dead deadline. They just want your house safe and up to code. So how can you protect yourself against irritating and time-sucking callbacks?

Top 5 common DIW (Did it Wrong) projects

Alan Husby, Code Inspection Specialist with the Planning and Development Services department in Snohomish County, north of Seattle, Wash., listed five common errors their building inspectors find in do-it-yourself projects.

1. Is there a draft in there? If you are lighting a fire in the fireplace, you want the flame to "draw," sucking up the chimney instead of clouding your room with black smoke. But that drawing is bad, very bad, if it happens inside a wall. Fire can swoop up the studs and suck into any space, spreading like, well, wildfire.

Any cavity must be sealed to prevent the easy spread of fire. Hence, openings, such as holes through studs and plates for wiring or plumbing, must be sealed, most commonly with spray-in foam or tufts of insulation. All vertical gaps must be filled, and horizontally, you must fill every 10 feet.

Stairwell framing and soffits over cabinets are common problem areas.

And, Husby said, "We often see draft problems when people finish off basements. They fur-out (meaning attach furring strips, before installing sheetrock) from the concrete to create their walls, but don't take the precautions to block the rapid flow of air." It is especially problematic because the studs do not snug-up against the concrete basement wall, leaving air gaps.

The result, in case of fire, is rapid conflagration.

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2. Size matters. A surprising number of people use the wrong size piping for their exhaust fans in the bathroom and laundry room, Husby said. The vent pipe needs to be 4-inch diameter, and it must be vented outside, not into the attic.

"Some cheaper fans have 3-inch outlets," he said. "Fortunately, Home Depot and Lowe's usually have adapters to four inches."

3. Rise matters. Stairs can get you every time. The rise of each step should be the same. If one step is 7 inches high, then all the steps should be 7 inches high. And that isn't necessarily easy to achieve.

A contractor once snorted to a homeowner: "You can always tell a DIY'er by how bad the stairs are!" And he proceeded to miscut his first stringer (the notched board that runs from top to bottom that holds the steps).

It's especially easy to miscut the bottom step because there is no tread below it. If you are using 1½-inch treads, and you cut the bottom riser the same as all the others, your first step will be 1½ inches too high.

4. Get a grip. On the subject of stairs, Husby pointed out that handrails cause as much problem as the steps.

First, they must be graspable. Especially on decks, a homeowner might use a 2-by-6 on the flat for his rail. "That's not grippable," Husby said.

And second, if the rail is against a wall, the ends must curve back to the wall.

"It's easy for a pajama or robe sleeve to catch on the end of an open rail, especially if a person is fleeing the house in the dark because of a fire," Husby said. A hooked sleeve at the top of the stairs can easily result in a frightened homeowner splatted at the bottom of the stairs a second later.

5. A huff over fluff. Lastly, Husby said, DIYers may use the wrong insulation. It is common nowadays for municipalities to require exterior walls be built with 2-by-6 studs and require a minimum of R-21 insulation.

"Home Depot sells R-11 and R-19, and people will use that," Husby said.

And, needless to say, they get upset when an building inspector tells them they have to spend more money to have their error rectified.

You don't want your project to be the butt of a building inspector's happy hour chatter. If you are unsure of requirements, don't guess. Find a certified local contractor, or call your planning department to learn the right way to do it.