I'm building the railings for my new deck and plan to use a 2x6 as the top board. 4x4 posts, 2x4 rails. How can I make it a bit slanted to help shed rain water with minimal tools? (No table saw, no router...).
You'd just slope the 4x4 posts, set the top rails on them, and fit your 2x4 rails underneath. A slight wedge gap would be present, but that's not going to look terrible.
I'd reconsider for a few reasons, though:
- You'll need a substantial slope to drain enough water to make a difference. We're talking about beads of water or, at worst, shallow puddling. Both require at least several degrees of slope to eliminate.
- This isn't going to substantially extend the life of the rail. Even if it did, replacing just the top rails after 10-15 years might be worth not creating conditions whereby...
- You'll eliminate the railing as a drink/dish platform. Don't underestimate the utility of that surface for you and your guests.
I'm in a moist climate and we routinely used 5/4x6 deck boards as top rails. Folks really liked being able to rest dishes and elbows on that wide surface. They didn't rot out any quicker than the hundreds of feet of decking below. A quick squeegee cleans them off after a rain.
I'm not sure it's worth the trouble if you don't have a saw to cut an angle off the posts. Odds are that the wood will dry out to whatever shape it wants to be anyway, either holding or shedding water accordingly. I find any water sitting on top of this board soon evaporates. Just make sure you keep up with the protection on the top board especially.
2x6 is so thick, I suspect you'll be long gone before it rots out and keeping it flat will make it more useful to put plates/drinks on etc. (assuming the drop isn't over someones head).
If you have a circular saw you can cut the slant from both sides following the image below. The offset equals the height of the slope you want (suggest 10mm which gives you about 5-6 degrees slope). .
I agree with some of the other answers and comments, but to answer the question as asked; How to slant the railing, without having a power saw to cut the post tops at an angle - Or the tools to cut slanted mounting blocks.
Consider using Composite Shims. Just like regular shims but weather proof: Example: 8 in. Composite Shim (Bundle of 12)
Experiment with the angle of the shims and cut to fit the top of the posts. You could glue or tack nail them together before attaching the railing.