I have a job to do for a customer! Woo Hoo!!
I have a sign that I will be building a frame for and mounting it to a brick chimney. The sign is approx 2' x 4' and it's a galvanized sheet with a paper sign behind a 1/16" plexiglass surrounded by a rather flimsy plastic channel. You've seen this before, it's essentially the same as a poster frame you might buy at Walmart. Not exactly good outdoor stuff, but it's what I have to work with.
So, my approach is to surround the sign in some 1x poplar (think frame and panel construction) and silicone it into the groove to insure it will stay water tight. The frame will have bridle joints at the corners and the groove will be about 1/2" deep. The whole thing will be primed and get a few coats of a high quality exterior paint.
Here's the question part - I will be attaching this to a wide brick chimney. There are many clinker bricks in the chimney so I will use some PVC pipe sections (about 2') as stand-offs. I think this will also add to the looks. When attaching to a brick structure, I assume I should only drill into the grout lines and not into the brick - correct?
Secondly, my first thought was to use anchors and long lag bolts, but the anchors can allow water to get into the wall and might cause freeze/thaw issues, maybe? So, my second thought was to drill holes and use long carriage bolts (better look on the front of the sign) and simply set them in silicone. This would prevent any water incursion.