Repair and Restoration

© 2008, Kenton Shepard

Although making recommendations concerning repair or restoration of logs problems lies beyond the scope of the General/Log Home Inspection, clients will ask about the severity of problems listed in the report and about methods for repair or correction. Inspectors should have at least a basic knowledge of methods available for repair or restoration.

DECAY

In log homes, as with conventional homes, aging causes deterioration. One of the unique aspects of log homes is that in most cases, the wood structure is directly exposed to the elements instead of being hidden behind a protective cladding as it is in conventional homes.

Because such a large percentage of a log home is composed of, much deterioration takes the form of wood decay.

REPAIRING LOGS

There is no part of a log home structure which cannot be replaced if necessary, although log replacement is expensive and should be a last resort. Badly-decayed logs can have only a section replaced, or methods exist for strengthening weakened areas.

MECHANICAL REINFORCEMENT

Mechanical means for adding support or reinforcement in steel or wood may be added when tensile strength is required, and may be either visible or hidden.  A section of log may be replaced- as is common with decayed log extensions- which for example,  might be the first 6 feet. A section may also be cut out of the side of a log and replaced with wood from another log.

RESIN REINFORCEMENT

A number of 2-part resin-based products are available for repair of damaged or decayed wood in logs.

Modern epoxies can be injected into holes drilled into decayed wood. The liquid epoxy is absorbed into and saturates decayed wood fibers, hardening into a water-resistant mass which includes both the epoxy and original wood fibers.

Epoxies can be used to help restore compressive strength.

BORATES

Borate is a water soluble chemical, non-toxic to humans, which will halt fungal growth. It’s available as a powder which can be applied to  log checks, or as dowel-like rods which can be inserted into holes drilled into logs. A common application is post bases which are exposed to water periodically. As wood surrounding a borate rod absorbs water, the rod will begin to dissolve and borate will diffuse through the wood, preventing decay from taking place. When wood dries, the rod stops disoving.

NON-CONTEMPORARY REPAIRS

When log replacement is necessary, either whole or partial, it’s always preferable to have replacement logs match the existing structure as much as possible. It’s not uncommon to see historic cabins with a timber foundation or with no foundation which have had modern, green, rectangular, pressure-treated timbers used to replace decayed lower logs. This condition might be described as a “non-contemporary repair”.

Non-contemporary repairs should be mentioned in the report, but inspectors should refrain from describing them in a negative manner or recommending correction. These repairs are often stabilization efforts which can usually be improved at a later date. It’s important to halt structural deterioration in historic properties.

STABILIZATION VS CORRECTION

There will be situations in which inspectors may want to recommend stabilization instead of correction. An example might be a situation in which long-term foundation movement has taken place which has caused the floor to sag slightly and/or wall logs to bow slightly. The problem may not be extreme enough to justify the expense of straightening the foundation, floor or wall logs.

In this situation an inspector might recommend stabilization rather than correction. Stabilization would include determining the cause of foundation movement and correction of that condition and any other necessary actions to prevent continued foundation and wall deterioration.

Heading photo courtesy of  Kenton Shepard

Sources for More Information

Preservation and Maintenance of Log Structures- University of Minnesota Extension Service

Preservation Brief # 26 U.S. Naitonal Park Service