BASEMENT STRUCTURES • Columns

carry the weight of the structure from the girders (or beams) to the ground. Columns transmit the weight to footings below. Often, you’ll find columns or posts put in to support an unusually heavy load such as a piano.

The home inspector identifies the materials used in column construction — steel, wood, or masonry. Columns should be inspected for their condition and ability to support the structure above. In steel columns, look for rust throughout

the length of the column. Rusting at the bottom shows water present at the floor level. Rusting higher up may indicate water from above running down the column or an unusually high moisture content in the air or condensation. In wood posts, look for and report evidence of wood rot

and possible insect damage. Masonry columnsshould be

inspected for the condition of the mortar.

The inspector should determine if the column or post is doing a proper job of supporting the structure above. First, look for footing problems (or the absence of footings altogether). Columns and posts should sit on their own footingsand be secured to the beamoverhead. They

should be plumb. A column or post that is out of plumb by over 1/3 its thickness may no longer have its structural integrity.

You may see a shimof metal or hardwood inserted

between the beam and column. The shim should be large enough to cover the interface between the beam and column. If it’s too small, the beam or top of the column may be crushed. Report on damaged or crushed shims. Refer back to Photo #30 for a look at the two columns

shown. The original steel column is rusted out at the bottom, and this should be reported. The column on the right looks like it’s been introduced to provide the support lost by the first. The bottom on any new column should be inspected carefully. Is the column simply sitting on the

BASEMENT STRUCTURES • Columns

• Sills and headers • Girders and joists

floor? Does it have a footing of its own? In this case, the new column is free standing. This was reported.

Take another look at Photo #35. This column is in good

condition, but the stress cracks and depression in the floor indicate that the footing below the column has settled. With a column like this, inspect the top of the column and see what’s happening to its ability to support the girders above.

• Sills and headers: The sill, sometimes called the sill

plate, or mud sill, is the portion of the framework that sits directly on the foundation and provides a pad for the bottom of the framing system. Sills today are 2 x 4’ s or 2 x 6’s laid flat on the foundation and anchored in place with bolts. The sill in older construction may be an 8 x 8 wood beam. Wood sills support wood framing members, but not masonry, which sits directly on the foundation. The

header, or rim joist, is nailed to the sill.

The home inspector should inspect the sill and header for rot. This can be caused by a defect in the siding, from soil too high around the exterior of the house, or water wicking up through the foundation. Suspicious wood should be probed with a screwdriver. Sometimes in cold climates, you’ll find a pad under the sill or mortar packed against the sill. Check the mortar for condition. The home inspector may find insulation around the top of the basement wall, in which case the sill and headers may not be visible.

A sill over a window opening may sag or break from stress without a lintel or header having been installed underneath. This should be pointed out to the customer.

For Beginning Inspectors

Try to view as many basements as you can. There’s nothing so helpful to the learning process as seeing these things for yourself. Pay attention to the girders and joists in particular. Make note of the different building methods you find.

Definitions

The sill, or sill plate, is a 2 x 4 or 2 x 6 laid flat on and anchored to the foundation, providing a pad for the framing system.

The header, or rim joist, is one of the framing members and is the perimeter joist nailed to the sill.

sill

Header or Rim Joist Sill

Foundation

Girder, Beam Joist

• Girders: Girders (or beams) are horizontal load-bearing

members of a floor system that carry the weight of the floor and wall loads to the foundation and columns. Girders usually run parallel to the long side of the house, but there may be others, shorter ones running elsewhere. Types of girders are large wood timbers, steel I-beams, lengths of built-up lumber, or glue-lams. A new development is the pre-fabricated girder-like truss.

Girders rest in pockets of the foundation wall, shown in the diagram on page 55, on the sill, or on pilasters attached to the foundation. There should be 3” to 4” of girder resting on end supports and 1/2” of clear space around the wooden beam where it rests at the foundation. Wooden beams should also have a waterproof material such as metal or polyethylene film between the beams and the foundation.

• Built-up beams(a 3-piece 2 x 8 or a 3-piece 2 x 10)

should have their butted ends staggered along the length and located over support columns and posts. The joint should be within 6” of the quarter point of the span of the beam. That is, if the beam is 12’, the joint should occur 3’ from either end, give or take 6” on either side.

There are no simple rules to follow to tell if wood girders are properly spanned,center-to-center on their supports.

It depends on the type and grade of the lumber . A 3-piece 2 x 10 beam should be able to span up to 10’ in most 2- story homes; a 3-piece 2 x 8 can span up to 8’ in a 1-story home.

There are, however, specific rules about what notches and holes can be cut into beams.

Rule #1: Mid-notches — where a notch is cut into a

beam along its length — should be no deeper than 1/6 the depth of the beam. A mid-notch is allowable only

INSPECTING BEAMS