Cedar shingles must be spaced, no and’s, if’s or butt’s!
Maibec recommends 1/8″ space between shingles.
See the PDF Instillation Instructions
The photo above is of some bowed shingles on a long run over two garage doors. The contractor told our forman that he wanted the shingles tight, a nice job. Our foreman told him of what the manufatture recommends. His responce was, just do it, it will be fine. Obvisiuly the incorect spacing caused a problem with the next rain and was not fine. Wood shingles are always moving, expanding and contracting with the humidity so they need to be spaced!
Always follow the manufactures recommendations.