Clean the log siding with bleach or a wood treatment cleaner. Follow the instructions on the wood cleaner. Use a hose and sponge to apply the cleaner. The wood cleaner or bleach also helps to make the logs more porous, allowing them to better absorb stain.
Clean the house with a pressure washer. Anything more powerful than 500 psi runs the risk of damaging the log siding. The pressure washer thoroughly rinses the cleaner from the wood and it cleans mildew and water stains from older homes. It also removes the old faded stain and gives you a clean surface for the new stain. Test the pressure washer in an inconspicuous spot holding the nozzle two feet from the siding. You may need to hold it closer, but holding it closer than 12 inches may damage the log siding.
Mix the stain very well. Stain has a very watery consistency. The pigment and color tends to stay at the bottom. Routinely stir the stain as you work with it.
Apply the stain with a wide-edge brush. Start at the top and work downwards. Only work on two or three logs at a time. The temptation is to do as many logs as you can reach before moving the ladder. This is faster but can result in overlap lines. Always keep a wet edge. Use long, even strokes and work slowly. If you move the paint brush too fast, the stain will splatter everywhere. Allow the stain to dry for 48 hours.
Caulk gaps and holes between the logs around the windows and doors. This may require a lot of work on a new home. If you are re-staining your home, the caulking stage will be less time consuming. Carefully inspect the windows, doors and chinking between the logs. Fill in holes and gaps. Remove dried or cracked old caulking with a putty knife and replace it with new caulking. Use a good-quality latex caulk. Allow the caulk to harden and dry for a day.
Apply a second coat of stain. This adds the finishing touch and better protects the wood, and the stain will last longer. Repeat the procedure from Step 3.