Are you considering purchasing an older home? Maybe you have plans of restoring it to its former glory. There are some things to be aware of when deciding to move forward with the purchase of an older home. When Bennett Property Inspection inspects an older home, for example a home built in the 1950’s we are doing this inspection in the context of the time period in which it was built, but balancing it against contemporary, acceptable building practices, and the general quality of the home.

Experience counts for a lot in evaluating older structures when you’re less familiar with the building practices and codes used for building the home. If your inspector has looked at many older homes, then they will have a much better your understanding of what was considered acceptable at the time the home was built.

The laws of physics haven’t changed with time, however, so many things that make a building safe or unsafe haven’t changed either. Older buildings, especially those that have been poorly maintained, present good opportunities to study the failures and successes of the various home materials and systems.

The elements that cause the deterioration of different home components have had longer to work on older homes. We use keen eyes and pay special attention at parts of the home that are exposed to the elements, such as the foundation, wall coverings and roof.

Foundation
The foundation is probably the main priority, since it’s the component that bears the load of the entire home. Foundation failure or repairs can be especially expensive, and parts of it may be hidden.  

Wall Coverings
The wall coverings often provide clues to any foundation movement. Soil or foundation movement typically shows up as diagonal cracks emanating from the corners of doors and windows. You may also see stepped cracking in masonry walls, especially near exterior corners or below windows.

Roof
The roofs of older homes in our area are typically shingles or tile. Often, the roof of an older home will need replacement soon, the owner or potential buyer may be facing not just removal of existing layers, but installation of solid roof sheathing over the original dimensional sheathing that was typically installed with older roofs in our area.

Structure
Older homes may have undergone work by someone not familiar with acceptable building practices. Although it’s often difficult to see floor and wall framing, we look for problems such as the structure being out of plumb, out of level, or not flat.
The work done may also have employed methods quite different from modern methods, so just because it looks different there maybe nothing wrong with it. It might just be a reflection of the era it was built in. We will look for theses types of issues and if they pose a concern.

Exterior
When lead was used as an ingredient in the manufacture of paint, the exterior paint coating would eventually oxidize, and a lead powder would form on the surface, ultimately washing into the soil around the home's exterior by the rain. Over time, lead can accumulate in the soil to a level at which it represents a health risk to children and pets. A lead test of the soil of the home's perimeter can be performed if its a concern of the potential buyer.

Windows
It’s often difficult to tell whether a window is original, and it’s a question that’s often asked. At Bennett Property Inspection, its our job to describe the window's condition. We look for failure of the finish coating and decay on wood-frame windows, especially in the corners of the sill. You’ll be checking for hardware condition, and proper operation of the hardware and window itself. Single panes are not a defect.

Electrical Systems
In inspecting an older home, we may find that the electrical system is original, that it’s new, or that it has had work done on it over the years. It’s not unusual to find electrical components from multiple eras in one home. They may all be energized, or they may be partially energized.

When we are confronted with these older systems, we recommend a specialist inspection by a qualified electrical contractor. The liability connected with electrical systems is high, since these can burn down the home or cause serious or fatal injury.

Plumbing Systems
There are still a few homes around with galvanized supply pipes, so we will check for functional flow at fixtures. Also, we will alert you to any unsafe conditions, such as missing or obsolete traps. In the past, lead distribution pipes have been a problem, but very few currently exist any longer.

Heating Systems
Serious problems can develop from poorly understood venting of furnaces and water heaters. Condensation is one problem. Water is a solvent and will deteriorate many materials. 

Where heating equipment has been vented through older brick chimneys, we will look for damage to the brick at the exterior, at the interior, and to the lining. We will also be checking for proper cleanouts, and if the chimney has a lining.

Toxic Materials
Sometimes we encounter toxic materials when inspecting older homes. Asbestos-like material on heating system exhaust ducts is something we most certainly look for and alert the client to. Asbestos was also used in vinyl products, such as flooring, and in the process of manufacturing roofing tiles. The amount of asbestos in thermal insulation has been exaggerated, but most thermal insulation releases particulates into the air when it’s disturbed, so you should wear a respirator in attics and crawlspaces where you may encounter exposure.

For questions concerning property inspections, or to schedule your property inspection, contact Bennett Property Inspection today at (813) 260-9920.

Knob-and-tube (K&T) wiring was an early standardized method of electrical wiring in buildings, in common use in North America from about 1880 to the 1940s. The system is considered obsolete and can be a safety hazard, although some of the fear associated with it is undeserved.
InterNACHI inspectors should always disclaim knob-and-tube wiring during their inspections.

Facts About Knob-and-Tube Wiring:

• It is not inherently dangerous. The dangers from this system arise from its age, improper modifications, and situations where building insulation envelops the wires.
• It has no ground wire and thus cannot service any three-pronged appliances.
• While it is considered obsolete, there is no code that requires its complete removal.
• It is treated differently in different jurisdictions. In some areas, it must be removed at all accessible locations, while others merely require that it not be installed in new construction.
• It is not permitted in any new construction.

How Knob-and-Tube Wiring Works:           

K&T wiring consists of insulated copper conductors passing through lumber framing drill-holes via protective porcelain insulating tubes. They are supported along their length by nailed-down porcelain knobs. Where wires enter a wiring device, such as a lamp or switch, or were pulled into a wall, they are protected by flexible cloth or rubber insulation called "loom."

Advantages of Knob-and-Tube Wiring:

• K&T wiring has a higher ampacity than wiring systems of the same gauge. The reason for this is that the hot and neutral wires are separated from one another, usually by 4 to 6 inches, which allows the wires to readily dissipate heat into free air.
• K&T wires are less likely than Romex cables to be punctured by nails because K&T wires are held away from the framing.
• The porcelain components have an almost unlimited lifespan.
• The original installation of knob-and-tube wiring is often superior to that of modern Romex wiring. K&T wiring installation requires more skill to install than Romex and, for this reason, unskilled people rarely ever installed it.

Problems Associated with K&T Wiring:

• Unsafe modifications are far more common with K&T wiring than they are with Romex and other modern wiring systems. Part of the reason for this is that K&T is so old that more opportunity has existed for improper modifications.
• The insulation that envelopes the wiring is a fire hazard.
• It tends to stretch and sag over time.
• It lacks a grounding conductor. Grounding conductors reduce the chance of electrical fire and damage to sensitive equipment.
• In older systems, wiring is insulated with varnish and fiber materials that are susceptible to deterioration.

Compared with modern wiring insulation, K&T wiring is less resistant to damage.  K&T wiring insulated with cambric and asbestos is not rated for moisture exposure. Older systems contained insulation with additives that may oxidize copper wire. Bending the wires may cause insulation to crack and peel away. 

K&T wiring is often spliced with modern wiring incorrectly by amateurs. This is perhaps due to the ease by which K&T wiring is accessed.

Building Insulation:

K&T wiring is designed to dissipate heat into free air, and insulation will disturb this process. Insulation around K&T wires will cause heat to build up, and this creates a fire hazard. The 2008 National Electrical Code (NEC) requires that this wiring system not be covered by insulation. Specifically, it states that this wiring system should not be in…

hollow spaces of walls, ceilings and attics where such spaces are insulated by loose, rolled or foamed-in-place insulating material that envelops the conductors.

Local jurisdictions may or may not adopt the NEC’s requirement. The California Electrical Code, for instance, allows insulation to be in contact with knob-and-tube wiring, provided that certain conditions are met, such as, but not limited to, the following:

• A licensed electrical contractor must certify that the system is safe.
• The certification must be filed with the local building department.
• Accessible areas where insulation covers the wiring must be posted with a warning sign. In some areas, this sign must be in Spanish and English.
• The insulation must be non-combustible and non-conductive.
• Normal requirements for insulation must be met.

Modifications:

When K&T wiring was first introduced, common household electrical appliances were limited to little more than toasters, tea kettles, coffee percolators and
clothes irons. The electrical requirements of mid- to late-20thcentury homes
could not have been foreseen during the late 18th century, a time during which electricity, to many, was seen as a passing fad. Existing K&T systems are notorious for modifications made in an attempt to match the increasing amperage loads required by televisions, refrigerators, and a plethora of other electric appliances. Many of these attempts were made by insufficiently trained handymen, rather than experienced electricians, whose work made the wiring system vulnerable to overloading.

• Many homeowners adapted to the inadequate amperage of K&T wiring by installing fuses with resistances that were too high for the wiring. The result of this modification is that the fuses would not blow as often and the wiring would suffer heat damage due to excessive amperage loads.
• It is not uncommon for inspectors to find connections wrapped with masking tape or Scotch tape instead of electrical tape.

K&T Wiring and Insurance:

Many insurance companies refuse to insure houses that have knob-and-tube wiring due to the risk of fire. Exceptions are sometimes made for houses where an electrical contractor has deemed the system to be safe.

Advice for those with K&T wiring:

• Have the system evaluated by a qualified electrician. Only an expert can confirm that the system was installed and modified correctly.
• Do not run an excessive amount of appliances in the home, as this can cause a fire.
• Where the wiring is brittle or cracked, it should be replaced. Proper maintenance is crucial.
• K&T wiring should not be used in kitchens, bathrooms, laundry rooms or outdoors. Wiring must be grounded in order to be used safely in these locations.
• Rewiring a house can take weeks and cost thousands of dollars, but unsafe wiring can cause fires, complicate estate transactions, and make insurers skittish.
• Homeowners should carefully consider their options before deciding whether to rewire their house.
• The homeowner or an electrician should carefully remove any insulation that is found surrounding K&T wires.
• Prospective home buyers should get an estimate of the cost of replacing K&T wiring. They can use this amount to negotiate a cheaper price for the house.

In summary, knob-and-tube wiring is likely to be a safety hazard due to improper modifications and the addition of building insulation. Inspectors need to be wary of this old system and be prepared to inform their clients about its potential dangers. 
 
For questions concerning property inspections, or to schedule your property inspection, contact Bennett Property Inspection today at (813) 260-9920.