Riser Height Calculator - Page 5

Love the calculator, helped me out of a potential argument about why they are needed in the first place

peace

Hey Guys,

Any links, docs, how-tos for building a riser?

Because of ceiling height, I am (foolishly, most likely) thinking about excavating a pit for my first row seating.

Just to double check I'm thinking about this correctly, I'd want to lower the height of the front row viewers head dimension when using this calculator, right?

Thanks,

-Dave

http://www.avsforum.com/avs-vb/showthread.php?t=966504

http://www.hometheaterstepbystep.com...aterRiser.aspx

This is good but what if you want to recline both sets of chairs bottom row and the row on the riser does the formula still work?

I am going to have 3 rows of seats and I was planning on doing two risers. The first two rows will have reclining theater seats and the back row will have a couch. I think that the first riser should be around 10" with the second riser only needing 8". First row will be 10' from the screen and the second row will be 15' from the screen. The back couch will be flush against the back wall which is 22' from the screen. The ceiling is 8' and the top of the screen will be 6" down from the ceiling. Any issues with this setup?

To verify the riser height was good, I put blocks under a chair until it sat at the height I thought I needed. I then put another chair in front of it and had someone sit on both chairs and look at the mock up of the screen. If the front person's head was in the way, more blocks were added.

two years after my original calculations I am still happy with my riser. Thanks!

I have a 13x17 (empty shell), not framed yet for HT. My key questions are

1. I have a family of 5 (incl 3 kids), I would like to have 2nd row seats is it feasible?

2. What should be raiser height? I have 106" diagonal screen and 7"7" floor to ceiling ht.

Attached is the plan...

Appreciate your advise...

The riser height calculator seems not to be working anymore, because the web page www.theater-calc.com appears to have expired 8-10-12, and has not been renewed...

Steve

Archive.org is a wonderful thing...

http://web.archive.org/web/20110202100424/http://theater-calc.com/

Good point, miltimj

Steve

I don't think you'll have much luck getting a cgi script to run on archive.org's wayback machine. Here's an alternate script I've been using:
http://diymovierooms.com/calculator_riser_height.aspx

True, I forgot about that, Jason.

Sorry I hadn't noticed the domain expired. Here's a new link:

http://calc.xn--f5a.net/

Thanks trunks for reposting the calculator.

What is a recommended distance for a screen from the floor and ceiling. Right now I'm thinking about 1 foot from the ceiling and 1.5' from the top of the stage, which would put it at 32" from the floor. Thoughts?

The distance from floor to bottom of screen will depend on your riser height. It needs to be high enough so heads in the front row don't block the bottom of the screen for people in the back row. Play with the mounting height variable in the calculator until it spits out a riser height that works for you. Your assumptions above sound like a good starting point. See if that gives you a riser height you can live with.

Actually, I'm trying to determine riser height. If I go with 32", riser should be around 11.32, if I go with 36" riser should be around 9.67. I really don't care either way but am trying to see what "norm" is, if there is a norm.

I guess another way to ask would be - should I center my screen top to bottom, or have more "black" at the top or bottom? What have others done?

I don't think there is a norm and it certainly doesn't need to be centered vertically on the wall. I would pick a screen height that ultimately gives you a riser that is easy to construct, say 2 layers of 3/4" ply on top of a 2x12 riser (3/4" + 3/4" + 11-1/4" = 12-3/4" riser). Would that give you a screen height that works? Does 12-3/4" work with your ceiling/soffit height?

Anything between 7" high and 12-3/4" high will be awkward. You'll go from not needing a 2nd step to needing 2 steps with very short rises.
Edited by Spaceman - 11/2/12 at 11:37am

Ok, with that said, I think I'll target a riser with 2x10s an then 3/4, 1/2, 3/4, to get me pretty close to 12" so I could get away with a single 6"ish step (and If I match the stage, fewer bags of sand!) Using the calculations in the first post to make an excel spreadsheet and then using the solver add-in I was able to solve for a screen at just over 32" from the floor.

I am so happy to have found this with a simple search. Now to make some measurements tomorrow & make a trip to buy the wood!

HI

@ trunks: how can we change the unit ? (by example if I want to calculate in metric unit )

Is your riser.cgi source code available in open source ?

Thanks

There has been considerable discussion about step height. Remember you will be walking in low light conditions so you should make sure the steps are comfortable to climb. A comfortable step height is in the 7 to 7 1/2" range for normal stairs between floors. In low light a shorter step might be good. It will also give you a wider tread to land on. I believe the maximum allowable height is 8", but two 4" steps would be more comfortable and safer.

A rule of thumb for designing stairs is rise + run = 17". So a 7" rise would have a 10" run. To satisfy building code, there must be a 1" overhang on the step giving a tread totaling of 11" wide. A 4" rise would give a 13" run, plus 1" overhang for a 14" tread. Both sets will feel "normal" to climb. Look for stairs in commercial spaces that have different size rise/tread and try them! Your brain knows!

In my humble opinion, all risers in one theatre should be the same height, as your brain calculates instinctively to anticipate the next step based on the one you're just climbed. Haven't you noticed when there is "something wrong" with a set of stairs? There is a variation in either the rise or the run between steps. Supposedly, there is one step in the Tower of London that is the wrong dimension so that anyone trying to escape will run down them and trip on that step.

Is there a source for some pictures or examples of actual theater builds and risers with labels of dimensions ?

hmmm.... Not sure I asked that right.

I'll try again.

I'm interested in seeing pictures of risers people have build with the dimensions labeled or disclosed for reference. Any good place for such ?