Monday, April 26, 2010
First, do you have a survey of the property? Will you need to create a site plan for approval? I’ve got a plot of property boundaries for my street but no individual survey boundaries marked on my property. A survey is my next investment. You may eventually need a surveyor to document the actual location of the house on the property for zoning and lender approval. Find out up front.
Do you have a plot plan of the property? Trace copies of it to lay out potential house locations.
What are your zoning constraints? What are the setback rules, i.e., how many feet from your property lines must you allow from your property lines for construction. Are there any other constraints? Research them up front.
Do you require a septic system? If so, you will need a perc test done before buying the property. This test will determine if the soil will support a septic system. The tester is licensed and digs pits with a backhoe, fills them with water and measures how long it takes the water to drain. Make sure that the test is performed where the system will likely be located. Multiple potential locations are recommended. Local regulation may have guidelines on placement of the system. Check them out.
Where are water drainage pathways on your property? Look for a location where water will drain away from the house. To circumvent this recommendation, plan on building retaining walls, draining tiles or other construction techniques to redirect/block water from the home.
Which direction should your home face? I’m going to orient my house to maximize the mountain views from the rear porch and large windows I will have in the rear. If energy conservation is more important, maximize solar heating and exposure to the South by orienting the elongated direction of the house to run east/west. Passive solar heating can reduce energy costs by 30 percent.
How about a driveway and parking? The further (and longer) from the road, the more expensive.
Have you factored in utility costs? How will the location effect how much will they cost to install?
Sunday, April 25, 2010
Cleaning - Clean the logs once a year. A hose rinsing with the assistance of a soft brush will suffice.
Re-stain – Water based stains should last about three to five years while oil based should last five to seven years. If the water doesn’t bead up the logs when cleaning, it’s time to re-stain. Make sure that you can recoat the existing finish. Apply and remove masking tape to the finish. If little finish is stuck to the tape, it should provide a good base. Otherwise, remove the finish with a chemical remover.
Cracks - Logs may crack and check as they achieve their moisture equilibrium level. Any cracks over a quarter of an inch should be sealed to prevent insect and water infiltration. Large checks should first be filled with foam strips (backer rod.) The cracks should then be sealed with caulk made specifically for logs. The caulk will handle the stretching and compressing of the log without cracking or pulling away. Caulk is also available in colors to match the stain.
Decay Fungi - Fungus can do serious damage to logs. Excess moisture is a common cause of the problem. Besides moisture control, wood should be treated to inhibit fungus. Boric acid, or borate, is an excellent fungicide that controls fungus. Borate also prevents insect damage. To promote penetration of borate into wood, it should be applied before water repellant treatment or after the finish has been removed from the logs.
Insects - The main wood boring insects that attack log homes are long horned beetles, flat headed wood borers, powderpost beetles and carpenter bees. As mentioned above, borate is the recommended treatment for treating or preventing insect infiltration.
Moisture Control – Prevent excessive moisture from logs. Cut back plants or trees that are close to or touching log walls. Good airflow helps prevent mold and mildew. Make sure gutters and downspouts are clear and properly directing water away from the foundation.
Friday, April 23, 2010
Most log manufacturers provide air-dried logs. The cants are stored outside, off the ground and preferably under a roof. The rate of drying is subject to local weather conditions such as humidity and the volume of air movement. It is a cheap but a relatively long process. The moisture content will eventually reach equilibrium at 15-20%. The process takes months to over a year.
Kiln drying is an accelerated but more expensive process. The cants are stacked in a sealed building and the temperature is slowly raised to 170 degrees F. Fans are used to move the air and dehumidifiers remove the moisture from the air. Due to the high temperature, the process kills fungus, mold and insects. It also causes any pitch (wood tar) to crystallize. The rate of drying is controlled by varying heat and humidity to minimize drying defects. Keep in mind that wood dried to a very low level will rehydrate once installed to the equilibrium level. A 19% moisture level is common.
Logs shrink as they lose their water content. Water in wood moves from areas of high moisture content to areas of lower content. The drying occurs on the outside first and then the inside. Splits and cracks result from the outer portion of the log drying while the inner portion remains saturated. Shrinkage of the outer portion is restricted by the wet interior and splitting can result.
There are two primary methods for measuring the dryness of the finished product. A moisture meter measures the resistance of the wood to an electric current. Current is impeded by moisture. This method only measures the outer portion of the wood. The second method determines the overall moisture content by weighing the sample wood before and after drying. The formula for the % moisture content is:
(weight before – weight after) / weight after
Tuesday, April 13, 2010
The National Bureau of Standards conducted a study to determine the relationship of a structure’s thermal mass to its energy consumption. The structures compared were a 7” solid wood log (nominal R-10) and an insulated wood frame with 3 ½” fiberglass insulation (nominal R-12). The results were:
Spring heating period - log structure used 46% less heating energy
Summer cooling period – log structure used 24% less cooling energy
Winter heating period – both structures used same amount of heating energy
The conclusion was that the ‘thermal mass’ of logs is an energy conserving feature.
Despite a lower R value, logs are more energy efficient than the wood frame/insulation structure. So what exactly is the R value? It is a measure of a material’s ability to impede heat flow. What is thermal mass? It is the capacity of a material to store thermal energy for extended periods, i.e., ‘heat capacity’ rather than heat impedance. Material with high thermal mass can absorb daytime heat and release it during the night. It serves to ‘flatten out’ the daily temperature fluctuations.
What type of wood species is best for your log home? There is no quick answer to that question. The simplest answer is whatever species the log home producer you choose offers. Their selection of species is primarily based on location. Besides the species, how the logs are milled, dried and treated effect the quality and durability of the log. The following is an introduction to log basics.
First, I will provide a little terminology primer. You’ve undoubtedly heard the terms hardwood and softwood. Believe it or not, rather than hardness, the distinction has to do with reproduction. Balsa wood is a hardwood. Need I say more? The classification relates to the trees seeds. If they are covered, the tree is a hardwood.
The outside of a log obviously determines its look but it is the inside that determines its durability. A tree is formed first with sapwood. Sapwood conducts sap/water from the tree’s roots to its leaves. Eventually, the inside rings die and become heartwood. The sapwood section continues as the youngest and outermost living wood. Heartwood is resistant to checking, splitting, twisting and decay. It can remain sound for hundreds of years.
The most common log home wood species are:
Eastern white pine great durability - creamy white to light brown - Appalachian and Great
Northern white cedar high % of heartwood - light to medium or straw brown -
Western Red Cedar high impermeability to liquids – light milky straw -
Bald Cypress Resistant to rot - medium yellow brown to amber dark brown – Southern states
Douglas Fir strong, used for key structural locations - orange brown to reddish brown – Pacific coast, Rocky mountain states
White Oak light to dark brown – Southern Appalachian and central states
Eastern Spruce creamy white - New
Yellow Poplar green or greenish brown - Southern states
The key to log stability is moisture content. Logs can be cut from dead trees or live (green trees) which must be dried. The drying process can be slow and natural or accelerated and use heat. The slow open air process will eventually (6 months to over a year) adjust the logs moisture content to that of the prevailing atmosphere. Kiln-drying exposes the logs to oven like heat for a period of two to three weeks. Kiln drying is clearly more expensive but produces logs that will settle very little once in place. The open air dried logs are more susceptible to shrinkage and builders must account for it when constructing doorways and windows. I’m leaning toward the kiln dried logs. It’s more expensive but I want my home tight and settled from day one.
The Log Home Council developed a grading system for logs. Grading relates to the structural integrity of the log rather than its aesthetics. There are 15 criteria that determine a log’s grading. Among these are:
Knots - The larger the knot, the weaker the wood
Slope of grain - Grain running parallel to the length of the log is strongest
Species - Some species meet criteria better than others. For example, yellow poplar loses its moisture content quickly and may check severely.
Moisture content – green are freshly cut trees, dry are seasoned and then kiln dried logs. Logs should have moisture content of less than 19%. Moisture content must be known to determine proper construction of doors and windows.
The bottom line is that you don’t want to build with ungraded logs. Graded logs can be a little more expensive but don’t forget a rule that generally proves out, ‘you get what you pay for.’
A few other log related terms.
Check – crack that develops in log as it dries
Grain – The quality of a log’s annual growth rings.
Knot - A portion of a limb that is in a log. They can reduce the logs strength.
Shrinkage – The decreasing size of logs as they dry
Settlement – Movement of walls over time as logs lose moisture
Rural land is a popular choice for a log cabin location. My top factors were the view (had to be a mountain), the terrain for building and then the price. There are a number of other factors that should be considered when choosing your property location.
Medical Care Retirees in particular need to be concerned about quantity, quality and distance to Medical facilities.
Utilities Does the property have access to public water, sewer and electrical utilities? My property has water and electrical access. There will be a charge for me to connect to the water line. I will need to put in a septic system. With a septic system, a ‘perc’ test is needed to determine if the ground drainage is at an acceptable level. I had the land developer pay for this test and guarantee acceptable results as part of my purchase agreement. Make sure you create a list of all utility related expenses you will incur and research what how much they are.
Other Access Concerns Where is the location of nearest water hydrant and fire department? How far is shopping? How far are recreation facilities? How far is regional airport? Are roads well maintained? Any problem with construction equipment and log delivery trucks getting to property?
Building Terrain My property is on a ridge and the slope of the building area is about thirty degrees. I will need a basement to accommodate the slope. That’s fine for me because the basement will provide the grandchildren’s entertainment and sleeping areas. There were a number of other properties available with better views but with steeper grades. A builder told me that retaining walls would have to be constructed on those properties…more money. Don’t forget what’s underneath the top soil. My brother bought some lakefront property but it wasn’t until the construction began that the rock ledge was uncovered…more money. And don’t ignore the possibility of flooding. Do your research!
Zoning and Development Research zoning rules for the area. How will future growth affect your enjoyment of the area? Will there be industrial development allowed nearby? What will be population density? What are rules affecting your building plans for the property? Does your land development have their own set of rules? I am pleased to say that mine does. The association has to approve all land improvements. No trailer habitation is allowed. There will be no miniature chicken farms. Do your research!
How much property tax will be assessed on your improved property at today’s rates? Will local infrastructure costs increase as area is developed? Higher taxes will surely follow. Fixed income residents need to be prepared.
Where do you buy land for your dream home? Like Robin and myself, many log cabin fans are looking for a rural mountain experience. We moved to an apartment just outside
The area surrounding our property is still quite rural. The three top industries are logging, cattle and chickens. Our property is located in the metropolis of Ranger, a ‘
Ranger is only an hour drive north from
In any case, now is the time to buy. Don’t wait until the economy recovers. If you’re a nature lover like me, I recommend the southern