these wood slats are utilitarian in the way they are connected to the substrate — countersunk screws — but note the care in angling the top of the projecting pieces, so water sheds off the wood. contemporary exterior by Fougeron Architecture FAIA
grout terrace joints with epoxy. This is similar to the joints of cement. However, these joints are waterproof, in contrast to addition of cement which can always suck up water (and may burst in winter).