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Home Buyers/Owners Guide to Log Homes InspectAPedia®  -     Guide to Diagnosing & Repairing Leaks & Other Problems on Modern Kit Log Homes Guide to Identifying, Diagnosing & Repairing Older & Antique Log Homes Log caulk, spline, gasket, and coating product guide for log houses Log checking, cracking, shrinkage, & Leaks in log houses and log siding Window & Door Installation Details for Log Homes can prevent later leaks & Damage R-Values of log home walls

This series of articles provides information on the inspection and diagnosis of damage to new and older log homes and includes description of log house and log siding insulation values and alternatives, and also a description of the characteristics of slab-sided log homes as well as all other types of log home construction. We include illustrations of log structures from several very different areas and climates in both the United States and Norway. Our page top photo shows a modern kit log home constructed in New York State.

For modern kit and factory-sourced log structures we include details of common construction and building defects that cause water and air leaks and ultimately rot damage and we point to key problem areas that need to be inspected carefully when buying or maintaining a log home. Also see Log Home Construction for a brief description of this building construction method and see Log Home Design, a U.S. Department of Energy guide to log homes and energy savings.

© Copyright 2009 - 1991 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

Guide to Log Home Inspection, Diagnosis, Repair for Owners or Buyers of Log Houses

Precision in manufacturing and assembly, combined with new sealants, gasket materials, and special wiring and other fixtures have reduced many of the complications present in traditional rough-hewn log homes. However even using the most carefully-engineered kit-type long construction methods, care and detailing during construction are important for durability and comfort in these structures.

Log homes sold as kits may have been constructed with varying levels of expert supervision. Examination by an inspector who is experienced in log construction can find some (not all) indications of the care that was taken during construction.

A Brief Catalog of Types of Log Homes and Log House Construction Methods for Modern & Antique Log Homes

As we introduced in our discussion of log house framing methods at Framing Methods as Indicators of Building Age log building construction is a very old construction method that remains in popular use today in the form of both traditional rough log house construction and in the use of manufactured log and kit log homes. Recent substitutes for solid rough logs and manufactured logs even include "logless" log homes made of concrete logs and fiberglass logs. As InspectAPedia focuses on the diagnosis and repair of buildings we refrain from aesthetic remarks about these alternative materials, though there are certainly practical considerations of cost, weight, durability, ecology, and availability of alternative log house and meta-log houses.

The author's opinions in this series of articles on the inspection, diagnosis, and repair of log homes, both antique and new, comes from having constructed, demolished, and repaired both antique log homes and new kit homes as well as from having inspected and diagnosed log home leaks, window installation, and structural concerns for owners and builders. We love log homes, but because these articles are designed to find and reduce problems in log buildings, our focus is on issues, not on the beauty, aesthetics, and comfort that can be found in log construction.

• Traditional solid log homes built of individually-cut (each unique) logs, originally set on or close to ground level or placed on stone foundations, later on concrete block foundations. Log homes (1640 - est U.S.) using solid logs were usually felled and prepared at or close to the building site, set on ground level, on flat stones on ground, or on a stone foundation, corners joined using various notch and overlap methods. Log homes were first constructed in North America by Swedes who had immigrated to Pennsylvania in the 1640's. Photographs and construction details of traditional solid log homes in the U.S. and in Europe are at Antique & Old Log Cabins.
• Manufactured solid log homes, built of machined logs or milled logs that are consistent in shape, diameter, straightness, and that typically incorporate a spline and gasket design between logs. After 1970 most log homes constructed in the U.S. used factory-cut and milled logs and log kit homes. Kit home logs, unlike their more rough ancestors, are milled to consistent diameters and use various spline and gasket methods to seal joints between horizontal and vertical members. Our photo at the top of LOG HOME GUIDE is an example of a milled-log home that we inspected in New York.
• Manufactured slab-log siding homes, built as traditionally stick-built 2x stud walls (insulated), having on their exterior half log or thinner rounded siding either cut from rough logs (rare in modern construction) or cut and planed from heavy lumber. Slab-sided log look-alike homes combine the appearance of a log home with conventional wood framed structures, making the installation of wiring, piping, and insulation a bit easier. See Slab Log Cabin Siding for an example of a slab-sided log cabin we put up on Lake Superior.
• Alternative-product log homes, constructed using logs cast in solid concrete (100 pounds per linear foot), hollow insulated fiberglass logs (one pound per foot), wood veneer on hardboard backer over foam core logs, or log-lookalike siding using pre-formed log-shaped styrofoam panels nailed to a building exterior and sprayed with concrete into which log-forming molds are pressed. For a recent news report of these new alternative "logless log homes" see the New York Times article we cite below.

Each of these design approaches has its fans and its detractors, and each approach has its own unique aesthetic, practical, cost, and maintenance qualities. We are collecting material for a table comparing the cost, weight, materials, durability, insulation R-values, and other considerations for each of these materials. Contact Us with any suggestions.

Below we begin a series of log home diagnosis and repair articles.

Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

LOG HOME GUIDE
    Types of Log Houses - Log Choices
    Antique & Old Log Cabins
    Cracks, Checking or Splitting Beams & Log Homes
    Condensation &Moisture in Log Homes
    Energy Efficiency of Log Homes
    LOG HOME WALL INSULATION VALUES
    Leak Diagnosis & Cure for Log Houses
    Log Wall Height Changes
    R-Values of Log Homes
    Sealants, Caulks, & Coatings for Log Homes
    Shrinkage In Log Home Walls
    Slab Log Cabin Siding
    Spline & Gasket Designs for Log Buildings
    Spline Gaps & Gasket Omissions
    Vertical Log Walls on Cabins & Homes

Quick Guide to Log Sealants, Log Chinking Products & Log Home Log Wall Coatings

For details about log home chinking, coating, and sealant products, please see Sealants, Caulks, & Coatings for Log Homes.

A traditional log home constructed of individually-cut rough (and varying-in size and shape) logs is shown in our photo at left. Concrete chinking was used, here painted white, to fill in the irregularities between the mating horizontal logs to stop drafts and water from entering the structure. Some of the really unfortunate disasters we've seen on log home exteriors were caused by use of a log coating or sealant which was not recommended by the log manufacturer. Use of the wrong sealant can lead to peeling and ugly surfaces that can be very costly to correct.

Here are some Log Home special sealants and caulking or chinking products. But before applying anything to the logs on your home, inside or out, find out what products your log manufacturer recommends.

• Geocel Caulk or other GE^TM caulking products specifically designed for log buildings
• Compriband^TM, an impenetrable sealant made by Secoa Corporation, Warminster PA
• Log Home Foam^TM, Norton Sealant Operations, Granville, NY
• Perma-Chink™, a flexible log chinking material that looks just like concrete, remains flexible, from PermaChink Systems, Knoxville TN 800-548-1231 (Photo at left was taken by the author of a sample provided courtesy of Perma-Chink) permachink.com. Our sample has remained flexible and un-damaged since PermaChink sent it to us more than 20 years ago.
• Lifeline^TM Natural Wood Finish (acrylic polymer) from Perma-Chink Corp.
• PR-5636^TM, poltyurethane sealant, Products Rersearch & Chemical Corp., Glendale CA
• Traditional mortar log chinking (we do not recommend this approach as it falls out, leaks, requires frequent repair)
• Preservative stains, pigmented, penetrating type: we've used these with success on slab log siding on log homes; a good practice for maximum durability and insect resistance of slab log siding is to seal all surfaces of the log siding before it is installed.

Producers of products for the construction, maintenance, repair or protection of log homes are welcome to submit product data for inclusion; there is no fee; our website has no financial relationship with any of the products or materials discussed here. Contact Us with any suggestions.

Heating, Cooling, and Insulation Values & Characteristics of Log Homes

R-Values for wooden log walls given by the U.S. DOE are in error except for square log walls. D-logs and round logs that are given a nominal log thickness, say 6" logs are calculated by DOE as having an R-value of just over 8. This is incorrect for non-square logs because the cross section of the log is 6" only at the log's widest point.

A correct assessment of the R-value of a wooden log wall needs to be calculated based on the average wall thickness, considering the variation in thicknesses over the curvature of the logs. Therefore the DOE's value is on the "high" end of the R-value of a log wall.

Slab-sided log homes that use conventional stud framing for walls will have about the same R-value as other wood-framed buildings of similar construction, plus the added value of the average thickness of the slab siding.

Air leaks in log homes (or in any home) will have a significant, possibly dominant effect on the home's heating and cooling costs. See Minimizing Air Leakage in Log Homes.

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Technical Reviewers & References

• InspectAPedia.com^® - Daniel Friedman
• InspectAPedia Bookstore lists recommended books, organized by topic & available for purchase. Most of our articles also include a list of recommended books for the specific article topic as well as other references, and information sources.
• Critique, contributions wanted: Contact Us to suggest corrections or additions to articles at this website, and if you wish, to receive online listing and credit as a contributor. Particular thanks are due to the many experts and also consumers who read and critique technical articles at InspectAPedia.com.
• Additional technical contributors & reference sources for this article are listed below.

Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

LOG HOME ENERGY EFFICIENCY
LOG HOME GUIDE
  Antique & Old Log Cabins
  Cracks, Checking or Splitting Beams & Log Homes
  Condensation &Moisture in Log Homes
  Energy Efficiency of Log Homes
  Leak Diagnosis & Cure for Log Houses
  Log Wall Height Changes
  R-Values of Log Homes
  Sealants, Caulks, & Coatings for Log Homes
  Shrinkage In Log Home Walls
  Slab Log Cabin Siding
  Spline & Gasket Designs for Log Buildings
  Spline Gaps & Gasket Omissions
  Types of Log Houses - Log Choices
  Vertical Log Walls on Cabins & Homes
  Wall Insulation Values in Log Homes
LOG HOME WALL INSULATION VALUES

• Thanks to Arlene Puentes for the photograph of a checked log in a log home exterior. Arlene Puentes, a licensed home inspector, educator, and building failures researcher in Kingston, NY. Photographs © Arlene Puentes 2006 All Rights Reserved. Text © Daniel Friedman Arlene Puentes 2008 All Rights Reserved.
• "The Logless Log Home," Jim Robbins, New York Times, 02/25/2010 Home section, p. D1 & D6.
• "Shop Talk," Martin Mintz, AIA, Builder Magazine, April 1986, detailed solutions for log shrinkage movement by using a "T" jamb at windows and doors. A January 1986 Builder Magazine article shows window installation details in 8" thick log walls.
• "Caulking, Chinking, Insulators, Sealants - which System works Best," Log Home and Alternative Housing Builder, Nov-Dec 1983.
• Lincoln Log Homes Marketing, Inc., 6000 Lumber Lane, Kannapolis NC 28081 704-932-6151
• Insulating Characteristics of log homes were neatly summarized by Roger Rawlings in "Log Homes in a New Light," Rodale's New Shelter, April 1983, p. 28
• Merrimac Log Homes, Henniker, NH, sells log home products, milled log home kits, log siding, and log home plans and log home construction accessories. 866-637-7462 or logs@mlhnh.com - merrimacloghomes.com
• PermaChink Systems, Knoxville TN 800-548-1231 provides a range of log chinking products, coatings, and sealants for log and other wood buildings.
• "Log Home Design", U.S. Department of Energy guide to log homes and energy savings (at www.energysavers.gov/your_home/designing_remodeling/index.cfm/mytopic=10350 ) includes these interesting sub-sections:
  • "The R-Value of Wood" for log constructed homes
  • "Minimizing Air Leakage in Log Homes"
  • "Controlling Moisture in Log Homes" and the more general (but brief) DOE article series on moisture control:
    • "Moisture Control", U.S. DOE
    • "Moisture Control in Basements", U.S. DOE
    • "Crawl Space Moisture Control", U.S. DOE
    • "Slab-on-Grade Foundation Moisture and Air Leakage Control", U.S. DOE
    • "Moisture Control in Walls", U.S. DOE
  • "Ventilation", U.S. DOE, describes the purpose of building ventilation and three basic ventilation strategies:
    • Natural house ventilation methods
    • Whole House Ventilation Methods, including exhaust ventilation methods, supply ventilation of buildings, balanced building ventilation, and energy recovery (heat exchanger) ventilation systems
    • Spot Ventilation in Buildings
  • "Weather-Resistive Barriers", how to select and install housewrap and other types of weather resistive barriers, U.S. DOE
  • "Vapor Barriers or Vapor Diffusion Retarders", U.S. DOE: how vapor barriers work, types of vapor diffusion barriers, installing vapor barriers
• "Whole-House Systems Approach [to saving on energy costs]", U.S. DOE, describes designing and constructing an energy-efficient home by considering all of the house systems. Original DOE source: www.energysavers.gov/your_home/designing_remodeling/index.cfm/mytopic=10370
  • "Appliances and home electronics", U.S. DOE on energy savings suggestions
  • "Insulation and Air Sealing", U.S. DOE describes how to reduce a home's heating and cooling costs by proper insulation and air leak sealing. Moisture control and ventilation are also discussed.
  • "Lighting and Daylighting", U.S. DOE, is a very brief DOE article suggesting how to reduce the cost of lighting in a building
  • "Space Heating and Cooling", U.S. DOE, attacks the biggest energy user in buildings, typically about 56% of energy use in a typical home in the United States.
  • "Water Heating", U.S. DOE, addresses reducing the cost of heating domestic hot water used for washing and bathing - that accounts for 14-25% of home energy usage in the U.S. and includes
    • "Selecting a Water Heater", U.S. DOE
    • "Energy Efficient Water Heating", U.S. DOE includes suggestions to lower hot water heating costs including reducing hot water usage, lowering hot water temperature, insulating the water tank (nonsense), insulating hot water pipes, installing heat traps on the water heater tank, water heater timers, and drain-water heat recovery systems (possibly not cost effective)
    • "Swimming Pool Heating" cost savings suggestions from the U.S. DOE includes suggestions on using a high efficiency (gas-fired swimming pool heater or heat pump swimmign pool heater) or solar swimming pool heater, using swimming pool covers, managing swimming pool water temperatures, and installing a more energy efficient swimming pool pump, or using it less.

Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair

• Our recommended books about building design, inspection, and repair, and about indoor environment testing, diagnosis, and cleanup are at the InspectAPedia Bookstore.
• Krigger, J.; Dorsi, C. (2004). Residential Energy: Cost Savings and Comfort for Existing Buildings. Helena, MT: Saturn Resource Management.
• ...

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