Pressure Impregnation

• This technique treats wood with a preservative quickly and completely. It is typically done prior to construction, but can be used on home exteriors after construction is completed. For outside preservation, creosote or pentachlorophenal may be used, but either can leave an oily residue on the logs. Copper preservatives are also available. A professional is required for this treatment.
  
  

Diffusion or Double Diffusion Process

• Completed prior to construction, simple diffusion is the process of soaking logs in a preservative solution for up to two weeks before drying. Double diffusion involves soaking the log first in one solution, then a second. The process causes a chemical reaction between the two compounds that prevents moisture from escaping the wood. Different strengths of treatment can be produced, allowing for woods with different levels of protection.
  
  

Preservative-Type Finishes

• Wood turns gray over time due to the introduction and growth of fungus. Water-based preservative finishes contain a fungicide to kill the existing problem and prohibit future growth. The color of the wood then ages to a tan or light brown. An insecticide in the formula can also prohibit wood-boring bugs from infesting the cabin exterior. These solutions can be brushed on to the exterior logs at any point, but power-washing the cabin first would be recommended to remove loose dirt and fungus.
  
  

Wood Stains

• Log cabins are typically left in a "natural" color, which can be obtained and protected through use of either a pigmented stain or a water-repellent clear stain. The former blocks sun damage from ultraviolet (UV) rays. Due to their chemical makeup, these substances do not blister or peel, as in the case of paint or varnish, providing better protection and less maintenance.