Window Box mount

[Michael Caiozzo]

Ok crew, I have a question for all the experienced builders out there. Here is the situation: moving into a new house with a deck, and the fiancé wants window boxes. I plan on making the the window boxes myself. Where I am have some issues is trying to decide how I will mount them to the deck rail. First let me say i am well aware of the metal brackets that you can use to hang the boxes off the rail. These however wont work simply because I am trying to make the boxes looks like they where built into the deck. So here is what I am thinking I will do(and what I need your opinion on). Mount a piece of 1x8"(depending on what size I make the boxes) perpendicular to the bottom of railing on the deck. I want to mount this "skirt piece" using pocket holes. From there I am thinking I will ether mount another piece perpendicular to the bottom of the skirt to act as a shelf for the boxes to sit on. Or the other option is to simple mount the back of the boxes to skirt. Obviously glue will be used in conjunction with the pocket hole as well as I will probably use 18ga brads to nail the skirt into the slates that are behind it. My question is do you think this will be strong enough to support the weight of 24" boxes with soil and plants or am I doomed to use the over the top deck rail mounts.
-Mike

[Michael Caiozzo]

This is a really bad drawing, but it is what I am envisioning

[Jeff Metcalf]

Hello Michael;

I looked at your drawing need to know a couple more facts to really be of help.

One is how long do you want to make the window boxes?

The other is what type of wood did you want to use for you're brackets?

Decide on the questions and we will see if we can get  you to something that will work.

Jeff

[Michael Caiozzo]

Hi Jeff! I was planning on making the boxes 24 inches long. As for the wood I am open to suggestions. Was thinking red wood but wasn't sure if I wanted to spend the money.... Probably go with oak. Again I am open to suggestions(I am just learning the fundamentals of woodworking).

[Jeff Metcalf]

Hi Micheal;
I would not use red wood for the brackets as it is to soft to support the weight oak would be a better choice , I would also consider making gussets at each end to support the cantilever and weight . Right angle triangles would be your best , I would also use titebond waterproof glue as well. How high is the balcony if you are on the second floor or higher you would want to make sure the weight will be support maybe do a load test with sand bags to see how much weight before the brackets fail .
Hope this helps Jeff