Stair railings and making a pitch block
Ok I installed some oak railings and balustrades this weekend for a customer. I have done this a few times but in no way would call myself a stair builder/railing installer. I read a couple of articles about installing railings so I went about making a pitch block by putting a square piece of stock laying on the stairs tread, pushed tightly against the riser. The block got as close to the riser as it could but it hit the nosing of the stair tread above so It was probaly 1 3/8″ away from the face of the riser. I used my level to lay across the steps then traced the rake angle on the pitch block. I assumed this would give me the correct angle to cut the angle on the railing to newl post, as well as the angles for all the balustrades to be cut at. It wasnt correct however, it was a good 3-4 degrees off. What gives? Another article i read said your not supposed to include the nosing of the tread in the measurements for making a pitch block. If thats so, then putting a piece of stock on the tread and tracing with a level across the stairs would always result in an incorrect pitch block when the finished treads are already installed. Whats the correct way and what are and arent you supposed to include in your measurements? I also tried a technique I read in a JLC article called the “up” method. This method gives you all the balustrade lengths for the rake angle height you’re aiming for, as well as, the angles in degrees. Pretty slick system! Being that my measurements were off somehow, this didnt really help me either. Anyone care to chime in? This was a really frustrating and aggravating day! It did come out looking really nice though and the client is happy.
Replies
You got the rake angle, you didn't subtract it from 90 to get the cut angle. And I'll wager you had some steep stairs if you were that close ( 3-4 degrees) from 45.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
A pitch block is a small model of the stair. It can be either from nosing to nosing or carriage cut to carriage cut- both should be the same. You can either use a CM to calculate the angle or use a framing square to lay out the angle. Example if the rise is 7 9/16 and the run is 10, you can use a framing square to make the marks and connect the dots. Either way you can then place the pitch block on a 2x along the nosing and see if one side is level.
The angle is determined by the rise and the run, the exact same thing as a rafter and gable studs.
If you had a roof that had an 8/12 pitch, you punch in on a CM calculator.
8 [Inch] [Rise]
12 [Inch] [Run]
[Pitch] = 33.69° (That's your angle)
You would set your saw almost at 37° and cut the gable studs with that angle. If you were to cut gable studs on a miter saw, you would mark the edge of the 2x gable stud and stand that up on edge with the 3-1/2" against the fence and setting the saw almost 37° and cut.That would be the exact same thing you do with the balusters.
If you have a 7-9/16 rise and a 10" run, you punch that into the CM.
7-9/16 [Rise]
10 [Inch] [Run]
[Pitch] = 37.10° (That's your angle)
Set the miters saw at that angle and cut all your balusters and pitch block.
Visualize the top rail as a rafter with the top and bottom angle cut at 37.10° and the balusters are the gable studs with the same 37.10° cut.
Hey Joe,
What I did was I measured from the finished riser out to the edge of the finished tread and got 10 1/4". Then i measured from the finished tread to the finished tread above and got 8 1/8". I entered 10 1/4" on my CM calculator as the run, and 8 1/8" as the rise. I hit pitch and got 38.4 degrees. I set my mitersaw to roughly 38.4 degrees and cut the railing. I then layed the railing on top of the stair treads and butted it into the lower part of the newel. I did this to confirm the angle was correct and you could see it was off a few degrees. I read somewhere that I shouldn't have included the nosing of the finished tread in my run measurement. What did I do wrong?
Craig
If you measured out to the finished tread and it was 10-1/4" the tread was actually 9" with a 1-1/4" nosing. Your pitch block should be the the width of the tread without the nosing and the riser height.
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Edited 11/12/2009 9:15 am ET by Joe
You shouldn't include the nosing because it changes the run. If the rise is laid out 8-1/8" and the tread is 9", that's what you have to punch into the calculator.You will get 42.08°Your framing square will be held 8-1/8" x 9" when marking the stringers. Your nosing adds an 1-1/4" to the tread making it 10-1/4" making it 38.40°.I hope this makes sense.Joe Carola
Here's a drawing comparing the 8-1/8" x 9" and the 8-1/8" x 10-1/4". You will see the difference between the two angles and why it won't work going to the nosing.Joe Carola
It's OK to work from the nosings as long as you use two of them to cancel each other out.In your drawing, set a scrap of 2 x 12 on the tread at the far left, touching the nosing above, and use a straitedge to scribe the pitch line.You'll get a pitch block with an 8 1/8" rise and a 9" run.AitchKay
Yes, because the run stays at 9". But what he was doing wrong was using 10-1/4" as the run.
Yes, beacsue the run stays at 9" Joe Carola
Right. He got in trouble when he reached for his tape instead of scribing a block directly.AitchKay
No I got into trouble by doing exactly what Joe said, I used 10 1/4 as the run. I didnt realize not to include the nosing in the calculations. In fact when I recut the rake angle it was 42 degrees just as Joe pointed out. Joe how do you do those computer drawings? I love em!!! I will have to relook at my pitch block, i still have it in my truck. By butting the stock against the upper and lower nosings of the tread i still should've gotten a 9 inch run. I will look, thanks everybody. I do love my CM calculator, it really does make life sweet when of course you punch in the right numbers!!
craig
Craig,"Sketchup 7". It's FREE!!!Once you download it you'll love it.....especially because it's free.http://sketchup.google.comJoe Carola
Edited 11/12/2009 1:16 pm ET by Framer
If you took the pitch block directly to your mitersaw and set the riser side against the fence. The cut angle would be the pencil line you transferred with your level.
If you set the tread side of your pitch block against the fence the angle would be incorrect.
I've done litterally hundreds of rails using a pitch block made just how you described.
It takes a while to get it right. 3 degrees off on the first one isn't so bad.
a few common mistakes:
Not turning the pitch block the right way for each cut.
Not labeling the sides of the block when you make it.
Not making sure that the fitting is sitting on the saw EXACTLY as it should.
Remember, the pitch blok is a representation of the actual rise and run of the stair. Often times, especially on your first few stairs? The actuall rail doesn't follow that stair as perfectly as we would like to think.
More than anything it takes practice AND a steady hand at the saw.
what am i missing ?....
if you lay out a stringer... and cut all the little triangles out.... each triangle is a pitch block.... pick one or use them allMike Hussein Smith Rhode Island : Design / Build / Repair / Restore
Framers don't save scraps for trimmers... other than like french fries and coke cans behind the mis-aligned fire blocking at the bottom of the stairs.http://www.tvwsolar.com
We'll have a kid
Or maybe we'll rent one
He's got to be straight
We don't want a bent one
He'll drink his baby brew
From a big brass cup
Someday he may be president
If things loosen up
ah....but mikey saves scraps.... then .... Voila !...
"here's your pitch block , mr. stair rail guy"Mike Hussein Smith Rhode Island : Design / Build / Repair / Restore
Not missing a thing...............
Some pretty good advice here overall..................but what most miss? Is that the only thing a pitch block is used for is to measure the angle of the stair in relation to Vertical and Horizontal.
SO long as you have a two sides square to each other? It works just fine by sliding it up until it touches the nosing and then laying a level or square across the nosing just as LJ Smith shows.
Most issues with angles come from two places:
The saw..........parts of the rail not being held in proper alignment against the table or fence.
The Stair. Often when a a level shows a tread out as little as 1/8-3/16th? Multiply that by the whole stair.......................and then............remember that the ballusters run plumb, not square to the tread as they go up. That alone can cause a 3 degree deviation in the cut of a balluster top.
The LJ smith guide is generally idiot proof,but the actual application takes practice before it works.
Here's the drawing going from nosing to nosing. You will see how you still get the 9" run.
I've been reading the posts to this quiry. And it's plain to me that many aren't in the stair bussiness. Point one, you only really need a pitch block, when doing a over the post railings. For a P to P, you can lay anything ( like a straight 2x4 or the rail ) up The stairs and once the angle is established ( which you can mark from the base of the newel ) that is the cut and length ( assumming the newels are plumb ).
Point 2-- for over the posts railings ( which I mainly do ), you use the pitch block for laying out all your cuts on the the fittings, volutes , etc. , and double checking that your cut is right. And I don't wip out any formula or cm to figure it out. I use the actual, what's there. Treads are in and I'm ready to do the railing.-- lay a straight 2x4 or the rail up the stairs, against the skirtboard ( to make sure you are in a straight line to stairs ), I then take a piece of scrap ( 3/4 x 5 or 6" x 7-8" long ) square cut on ends-- lay it on the 2x or whatever and draw a line on it with a level, cut it with the miter saw forming a right angle triangle. Lay it back on and check with a torpedo, usually needs to retrimmed a couple time to get it right on with the torpedo. This is a workable pitch block. You can then use it to mark all the cuts on your fittings , volutes , etc. . And since I cut all my fittings at the same time ( first step in doing the railing ) and I also have my miter saw bolted to a specific purpose table, that I level, so I can also use the pitch block and torpedo to double check the fittings and volute are rightous. In my area ( with our codes ) most run about 37-38 1/2 . And you need to make sure your angle cuts are right-on -- since a volute needs to be level on the bottom newel and fit to the goseneck or whatever at the end of a 12-15' run of rail, so if you are off by so much as a 1/2 degree, you might have a level or gap problem.
It might also be noted, that if the stairs has a landing etc. , I make a separate pitch bloch for every run, since they are generally a bit different ( 1/4 to 1/2 degree ), go figure. Also since I am working on a leveled miter saw and table, with my volute jig, I can dial in the miter saw bevel with the block and torpedo ( against blade ). Then all you need to rember is to mark a fitting, it needs 2 marks on it, top and bottom of fitting. and depending on whether it is going up hill or down hill, determines if you mark bottom with block laying down ( at bottom ) and cut line with it standing up, as in a volute or opposite for rail side of an up easing to a gooseneck.
Not to knock formula's and CM's for many other given purposes, but when you can make a jig ( pitch block ) to what is really there, it is more opp's proof.
Roger
Good post.AitchKay
Thanks for your reply. In my first post, i stated that i definitely don't consider myself a stair or railing installer. Props to you for doing this type of work because I consider it the most challenging form of carpentry there is! I know I could've laid the railing on the stairs against the posts to get the angles, but i like figuring out formulas and like to use my CM calculator. ur definitely right about using whats there. In the future i will probably just go that route. My real issue was how I made the pitch block incorrectly because I included the nosings of the treads in my calculations for stair run.