The Best Spacing Between Red Cedar Shingle Siding

Wood and Moisture

• One of the first things to keep in mind when installing wood siding is that wood naturally swells when it comes into contact with moisture. As a result, untreated wood shingle siding has to have some type of spacing between the pieces that butt up against each other to allow for this movement. Usually between one-sixteenth and one-eighth of an inch is included, but your shingle manufacturer could have different requirements. Treated shingles can generally be fit snug, or up to one-sixteenth of an inch apart.

Seasonal Movement

• As a general rule of thumb, any type of installation requires that there be around one-sixteenth of an inch between the various elements to allow for seasonal movement. Seasonal movement is the expansion of components in the warm, summer months and the reverse in the winter months. With wood shingles for siding, a layer of waterproofing underneath the siding protects the home from eventual water damage, and the shingles themselves need to have a little space to breathe with the weather.

Installation Protocols

• Always follow the manufacturer’s instructions when it comes to installations and the spacing required. For example, most tongue-and-groove installations only have gaps at the top and bottom of the wall to allow for movement and expansion/swelling, while board and batten installations have around one-eighth of an inch between the pieces, which is then covered by another board to hide the gap. The pattern of shingles you install dictates the exact spacing, which the manufacturer determines.

Caulking

• Another aspect of siding is whether or not you need to caulk the gaps between the shingles of siding, or if they are meant to be installed without caulking. This is yet another aspect that revolves around the manufacturer’s recommendations. For example, tongue and groove shingle patterns most often only have caulking at the top, bottom and along the sides of the walls, while panel shingles will sometimes use caulking in between the vertical sections, with flashing along the horizontal sections over gaps.