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...).

  • Define "minimal tools"? You've got to have some sort of saw to cut pieces to length, right? I presume you want the slant outward to shed water off the deck, not on to the deck. Use a level to get the rail dead flat, then adjust it so the bubble is slightly higher on the inside of the deck.
    – FreeMan
    Aug 18, 2020 at 12:37
  • The best bet is to not use a 2x6 as a railing. Use something narrower that won't hold as much water in the first place. My railings are roughly 2x4 that I purchased premilled with a bevel on each side and square holes premilled in the bottoms to accept the balusters. They'll hold a drink with no problem, but a plate would be a bit of a balancing act, I guess.
    – FreeMan
    Aug 18, 2020 at 12:42

3 Answers 3


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). cutting slopes on posts.

  • 6
    To your point, ensure that the growth rings (as seen from the end of the board) curve down when installing the railing. That will help ensure that any cupping causes the cup to go down, thus naturally shedding water. If allowed to cup up it will, well, be cup-like and hold the water in.
    – FreeMan
    Aug 18, 2020 at 12:39
  • 4
    A treated 2x6 rots out in 20-30 years in climates with regular rain. That said, it wouldn't be disastrous to have to change out just that rail board after a couple decades.
    – isherwood
    Aug 18, 2020 at 12:41
  • 2
    @FreeMan I had never heard of putting the growth down to prevent water from pooling but it makes a lot of sense. I learned something new today thanks.
    – stoj
    Aug 19, 2020 at 12:56

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.

  • 1
    How do you propose using these? On the post? On the rail? Both? Some detail would be great.
    – isherwood
    Aug 18, 2020 at 20:23
  • I do have a skill/circular saw (just no table saw or router)
    – Max M
    Aug 18, 2020 at 23:33
  • Table saws and routers are no use to you for cutting a slant on the top of posts. A mitre saw is easiest, but you could use a circular saw to cut slants. Line the posts up on a flat surface (offset by the height of the slant required) and cut all of them in one go. Flip them over and repeat on the other side. If the posts are already fitted, then it's a challenge...
    – handyman
    Aug 19, 2020 at 7:58

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