Home Renovation: The Cellar and the Attic

When undertaking a renovation project, an examination of the out-of-sight, out-of-mind spaces may be useful. If you're thinking about converting an unfinished basement or attic area, this part of the inspection tour is especially important. In general, the least expensive way to add living space is by finishing unused areas—but to do so, those areas must be dry, adequately ventilated, and spacious enough to be usable. Even if you have no intention of converting any of your cellar or attic to living space, this step in the inspection process can still be valuable for the insights it can offer into the structure and working systems of your home.

When inspecting the cellar or attic, wear old clothes. A long-sleeved shirt and trousers are best, along with sneakers or work shoes. Basements and attics tend to be dirty and damp, and have awkward spaces that may require getting down on all fours. A couple of simple tools will be useful, too: a tape measure, a hammer, jackknife, maybe a screwdriver, definitely a flashlight. Grab your clipboard and you're ready.

The Foundation. In areas where the ground freezes in winter, the foundation must reach below the frost line. That means the base of the house is buried below grade to a depth so that the freezing and thawing cycle won't cause it to move. The cellar may be tall enough to stand up in (a full cellar); it may be a half-cellar called a crawl space; there may be no cellar at all if the place was built on a simple slab of concrete. In all cases, the principle remains the same.

When inspecting your cellar (if there is one), you're looking for bad news first. Investigate the perimeter of the foundation. There are three categories of trouble common to basements: uneven settlement; dampness and decay, and insect infestation. You're seeking signs of all three.

Uneven settlement means that certain portions of the foundation have settled more than others or that the action of the frozen ground has heaved some sections upward. Cracks in the wall are the classic sign of uneven settlement. When the walls are made of block, settlement cracking may resemble a staircase, climbing from one block to the next. Don't panic if you find hairline cracking, but cracks of more than an eighth of an inch should be noted prominently on your list of issues to discuss later with your designer/contractor team.

What is the floor? If it's just dirt, then water problems are likely, as the dampness can rise up every time there's a heavy rain. Except in very arid climates, however, some basement dampness is normal. However, puddles or serious water stains on the wall can indicate the presence of too much water.

Keep an eye out for any signs of insect damage or structural decay in the wooden members, which occurs when wood is alternately dry and wet. You can test for decay using your screwdriver to probe for softness. In some unobtrusive location, jab the tool into the wood—the force required is more than a tap but less than a punch. If the driver penetrates the wood easily and deeply, serious rot is present. Make a note of it.

Insect damage is most likely in damp, dark environments. If in probing any wooden structural members you find channels in the wood ("galleries"), you probably have a termite or carpenter ant infestation. Note whether there are tiny pellets or gray residue (that's insect excrement). Wood dust on top of foundation walls or on the floor far from any recent saw work can also indicate the presence of carpenter ants or powder-post beetles. If you see lots of tiny, round holes in wooden members, those are exit holes for beetles. Cobwebs with a dusting of what looks like sawdust is another sign. If the wood dust is a bright yellowish brown, it's recent; if it's gray, it's been there a good while. Again, if you find insect signs, add that to your list of items requiring further investigation.