Log Cabin Siding Installation Guide

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Tools and Supplies You'll Need

  1. Hammer
  2. Ruler
  3. Snips or Saw
  4. Square
  5. Chalk Line


Begin the log cabin siding installation with proper placement and leveling of the starter trim.

Log Siding Starter Installation

In order for Log Siding to be properly installed in a level fashion, the starter at the bottom of the wall must be level.

Determine the lowest point of the wall that will be sided; from that point, measure up 1/4" less than the width of the starter and partially drive a nail at one corner. Attach a chalk line; go to the next corner and pull the line taut. Make sure the line is level by using a line level or a 4' level.

Snap the chalk line and repeat the procedure around the entire house. Using the chalk line as a guide, install the top edge of the starter along the bottom of the chalk line, nailing at 10" intervals. Allow space for the corner posts, J-channels, etc. Keep the ends of starter strips at least 1/4" apart to allow for expansion. Leave approximately 1/4" between the starter and the corner post. Nail in the center of the starter strip nailing slots.

Using j-channels around your window will ensure the exterior siding fits flush and properly.

Log Siding J-channels Installation

J-channel is used around windows and doors to receive the siding. Follow the steps below when applying trim in your home DIY plans.

Cut and bend the tab of the top piece of J-channel down to provide flashing over the side J-channel.

Fold the bottom end of the side piece of J-channel inward at the bottom of the window, to fit over the existing J-channel to prevent water from entering under the sill.

Cut the side J-channel members longer than the height of the window or door, and notch the channel at the top.

Miter cut the free flange at a 45° angle and bend the tab down to provide flashing over the side members. A similar miter and tab may be provided at the bottom of the window, depending on the sill's condition. The J-channel should fit snug to the window.

To trim the bottom of windows, and at the eave, J-channel can be used with the undersill molding inside the J-channel. The J-channel and undersill combination will secure the cut siding panel and help to keep the alignment straight. Dual undersill molding combines both functions into one part. Cut and secure dual undersill similarly to using J-channels.

Outside corner posts will help keep your exterior siding in place and properly aligned.

Log Siding Outside Corner Posts

The installation of the Log Siding outside corner posts is important as these corners are an integral part of the wall system.

A water resistant material should used to flash the inside and outside corners a minimum of 10" on each side. Place the corner post in position, allowing a 1/4" gap between the top of the post and the eave or soffit.

Position a nail at the top of the upper slot on both sides of the corner post, leaving a 1/32" gap between the nail heads and the corner posts. The corner post hangs from these nails.

The balance of the nailing should be in the center of the slot, 8" to 12" apart, again leaving 1/32" between the nail head and the corner post. This allows for the expansion and contraction to occur.

The corner post should extend 3/4" below the starter strip. Make sure the posts are plumb (i.e., vertically straight).

For a better finished appearance, remove a 3/4" portion of the nail them on both sides of the corner post.

Exterior siding panels should be locked into the starter trim and slid into the corner.

Installing the Log Siding

As with all home DIY vinyl siding installation, the first row is always the one that will guide the rest of the wall. Start your log siding installation the right way for an easy installation.

Place the first vinyl log siding panel into the starter trim and then slide it into the pocket of the corner post. Fasten the panels in the center of the nailing slots. Allowance should be made for expansion and contraction by leaving a 1/4" gap between the siding and all corner posts and channels (increase to 3/8" when installing in temperatures below 40° F).

Do not drive the head of the fastener tightly against the nail slot. Leave 1/32" between the fastener head and the vinyl (about the thickness of a dime). Do not force the panels up or down when fastening. Panel locks should be fully engaged; however, the panels should not be under vertical tension or compression when they are fastened.

Since vinyl siding moves as the temperature changes, make certain that the vinyl panels can move freely in a side-to-side direction once fastened. Check every fifth or sixth course for horizontal alignment. Also check siding alignment with adjoining walls. When panels overlap, make sure they overlap by one half the length of the notch at the end of the panel, or approximately 1". The foam insert in the back of the panels should but together.

Always overlap joints away from entrances and away from the point of greatest traffic. This will improve the overall appearance of the installation. Vinyl siding panel seams should be staggered along the installation and should be at least three courses apart.

Finishing off your log cabin siding installation will depend on the amount of spacing left at the top of the wall.

Installation under window and crown area

Several options are available to secure the topmost panel below the eaves or windows. Depending on where the log siding panel has to be cut, it is imperative that you follow one of the methods below:

If the Log Siding is cut in a thick section of the panel; Cut the Log Siding and punch snap locks every 6" to 8". Push the panel securely into the top J-channel.

If the Log Siding is cut above or below the thickest section of the panel; Place a smaller 5/8" J-channel inside the 1 1/4" J-channel to act as an undersill trim. Cut the Log Siding Panel to the appropriate dimension and punch snap locks every 6" to 8". This allows for the expansion and contraction to occur. Push the Log Siding Panel securely into the 5/8" J-channel.

If the Log Siding panel is cut above the foam section of the panel; Install an undersill trim in the top J-Channel. Cut the Log Siding Panel to the right dimension and punch snap locks every 6" to 8".

Snap lock the Log Siding Panel into the J-channel, checking for proper free movement.

Important Info...

Be sure to follow and obey all safety rules and recommendations set forth by tool manufacturers.

Always follow any, and all, local, state, and federal building codes.  Always comply with any specified clearances set forth by the manufactures of stoves, fireplaces, furnaces, and any other heat sources, as well.