Help with angles and cutting.

[David Feldbaum]

So I am trying to wrap up this deck project since I started in June. I am 95% done but stuck on the last remaining railing which seems the hardest. I have found that the angle is either a 30 or 60 degree depending which way I put my angle finder on the stairs over a board. That being said I am still confused how to really calculate. As you can see from the photos I want the top flat railing to be a seamless transition into the stair top railing if that's even possible, and then get screwed into the post. I have a compound miter saw and it will give me the 30-31 degree angle, but I cant do 60 at all. Am I missing something, or is there a special trick to get the right measurement and proper cut with the tools I have? Your help is greatly appreciated. Once complete and stained, I will upload full project photo in the proper threads.

[Rich Engelhardt]

My favorite Youtuber 3X3 Custom (Tamar) did a video not too long ago on how to do this.

https://www.youtube.com/watch?v=iUOxyFCwFJ8&t=769s

[Lisa Starr]

In order to match onto the top railing both the top railing and the railing going down the stairs need to have an angle cut on them. So, if the angle measures 30 degrees, you need to cut a 15 degree angle on the end of the top railing and a 15 degree angle on the stair railing.

[Tom M King]

To add to what Lisa said, the post will need a relief cut too, allowing for the stair handrail to go down to the proper height for the tops of the two handrails to meet properly. You can see that the heel of the angled cut on the horizontal handrail will now be behind the plane of the edge of the post.

No special tricks, or tools. I would have just used an angle-divider, and sliding bevel, and not worried about what the angle is.

[Eric Schmid]

You want to determine the stair rail height independently from the flat rail. This is typically done off the stair nosing(s). The desired rail height is plumbed up from the nosings. Since the flat rail post at the top of your stairs is set back, what appears to be several inches, the stair rail is not going to terminate at the same height as the top rail.

By flushing the tops of the flat rail and stair rail, you are increasing the height of the stair rail relative to the nosings. You likely no longer have a code compliant stair height and the stair rail will look out of scale. This is why your 30 degree cut at the top is floating over your bottom post. Look at some photos of flat rail to stair rail transitions to see how this is typically done…especially for decks.

Try laying a straight edge along the stair nosings; one that extends post to post. Then measure up to your desired rail height (bottom of straight edge to top of rail). Check your posts for plumb and determine if you’re hitting all stair nosings. Small variances add up quickly at stair angles. Once you have a mark on the top and bottom posts, lay a straight edge on those marks at the stair angle and clamp to the posts. With your tape measure place a mark on each edge of a level. With the level plumb up from each stair nosing to check if your straight edge is at the correct height above each nosing. Adjust as needed.

Your straight edge is now at the correct height and angle. Mark the angle at each post. This is your cut angle. Transfer to your miter saw and cut your rail. You also have the length on this straight edge/story stick.

Finally, if you want to hide the end of the top rail, “turn it down”, by cutting a down turning miter on the board and a small mating piece.

[Tom M King]

Since that post nearest the stairs is not That far back from the nose of the top tread, I believe the stair handrail height will still be within code range, if the handrails meet at the angle.

All this really needs to be planned out before starting the job.

[David Feldbaum]

Thanks for all comments so far. I will check out the video, then dissect what Tom just said since its a little beyond my capability of thinking of math. With regards to the stair bottom post, i don't have to cut it that height. I just assumed it has to be the same height as all my other posts for the main deck railings. I have extra 4x4 posts I can cut to length. Just not sure what the protocol is for this last bit. If there is a code for certain angles to be followed when it comes to stair railings.

[Tom M King]

No code on angles. Just rise, and run for the stairs, and heights for railings. It will save a lot of trouble to be able to replace that bottom post. I never think in terms of angles when building steps, and railings.

edited to add: Before you go farther, Google: stair and railing code in pictures

and you will find all the information you need. It's one of those things that's not complicated, once you understand it, but not something you want to figure out by cutting one piece at the time, in progression.

[Bill Dufour]

One thing to keep in mind is that most wood working tools measure the angle differently then a geometry textbook. What a text book calls 90 degrees many tools will measure as zero degrees.
Bill D.

[David Feldbaum]

So i an basically attach my top railing now, since it has no bearing on the angle for the stair top railing? I think i was trying to over think things and make cut angles to both pieces so they would interlock almost. So the top railing has the 90 degree angle, and the stair is the one that gets the angle.

[johnny means]

So i an basically attach my top railing now, since it has no bearing on the angle for the stair top railing? I think i was trying to over think things and make cut angles to both pieces so they would interlock almost. So the top railing has the 90 degree angle, and the stair is the one that gets the angle.

That's exactly what it is not. Both rails must have identical angles or the butt joint won't match up.

[Derek Cohen]

Thanks for all comments so far. I will check out the video, then dissect what Tom just said since its a little beyond my capability of thinking of math. With regards to the stair bottom post, i don't have to cut it that height. I just assumed it has to be the same height as all my other posts for the main deck railings. I have extra 4x4 posts I can cut to length. Just not sure what the protocol is for this last bit. If there is a code for certain angles to be followed when it comes to stair railings.

No Math. Using a sliding bevel to transfer the angle.

Regards from Perth

Derek

[Rich Engelhardt]

I will check out the video

Keep in mind - the video I linked to is just a show and tell on how to cut obtuse angles on a miter saw where you are limited to making a 45 or 46 degree cut.

[Jack Frederick]

I think I would have run the top cap past the top of the post. You then run your stair cap into the post below where the top cap sits. Doing the butt joint at the top , with weather changes etc will be difficultly to hold over time. I offer this assuming you have the height to meet the code requirements

[David Feldbaum]

the idea was to have the top railing flow into the stair railing. I have seen other designs that you stop the top railing at the post, and then your stair railing cut on the angle attaches to the post. I have my angle of 31 degrees which I know is right. Johnny posted above that the top and stair rail need to both be angled. Are they the same then?IMG_0875.jpgIMG_0875 2.jpg