Stairway risers and treads: acceptable and preferred dimensions.
The riser-tread relationship is a significant factor in stair safety. Stair dimensions are calculated using a ratio for the proportion of the riser to the tread that is. stripping the wood and resulting in a weak connection. The only requirement was the sum of the height of two risers and the width of one tread The height of the railing above the tips of the stair treads is very important. Steps are made up of the tread, which is the part you step on, and the rise, which is the part you trip on! It's important to have the right ratio of tread to rise to make.
The concept is fairly straight forward - create treads of equal length and risers of equal height in a given space. However, it confounds many apprentice carpenters! I can only imagine how a homeowner might feel when faced with creating stairs. The most common stair building errors include: The angle where treads meet risers is simply a 90 degree angle. It just so happens that a standard framing square is permanently set at this angle. Look at Figure 1 for a moment.
It is a drawing of a framing square that is resting on the side of a long stair stringer. The tread depth and riser height are not indicated in the drawing. That is OK, because it doesn't make a difference!.
Find the right tread and rise for your outdoor steps | Garden Gate
No matter what the measurements are, the angle between them treads and risers will be maintained at 90 degrees. Figure 1 The angle that does change depending upon your situation is the angle of the staircase in relation to the floor lines. If the staircase is steep, then this angle will be greater. For example, if you were crazy and built a staircase with a 12 inch tread and riser, then the angle of the stringer to the floor would be 45 degrees.
Building Simple Staircases - Ask the Builder
A more common angle is about 37 degrees. You can achieve this if you build a staircase with a 7. You generally don't have to worry about the degrees of this angle? Because the framing square will automatically calculate it for you. Your challenge is to do the math that permits you to create a staircase that gets you as close to the tread and riser limits as set forth in your local building code.
I can't quote for you what the standard is, simply because there are different codes across the nation! That code stipulates that the " If you have existing floors you simply measure the distance from floor to floor where the staircase connects at each floor.
Failure to do this will goof up your measurements if the floors are not level! You can see how important this is by looking at Figure 2. Figure 2 If you are lucky and have no obstructions in front of the staircase where it hits the lower floor, you can let the staircase "run out" some even measurement.
For example, choose a 10 or 11 inch tread. Imagine if you will, that the distance between the two floor levels happens to be If you choose 7. You end up with 15 risers. Remember, you will always have one less tread than risers. In this case, you end up with 14 treads. To measure your total rise, you need to go out this inches and measure up and back to where the stairs end at the floor above.
The Layout Look again at Figure 2. See the dashed lines that represent the treads and risers? Perhaps you have seen staircases with notched stringers like this. These notches cut away wood that reduces the weight carrying capability of the staircase.
Imagine if you simply slide the dashed lines to the right so that the treads fall within the stringers? That is how we are going to build our staircase. The framing square allows us to do just that. Look again at Figure 1. Notice how the framing square operator is drawing the second tread line.
It is parallel to the first tread line. Note how the framing square rests on the stringer. See the 90 degree relationship between the riser and th tread?
The vertical distance once the stringer is in place will be the actual riser height. Thus, the treads and risers are simply a series of parallel lines. Look, once again, at Figure 1. One of the most confounding tasks is cutting the vertical plumb cut at one end of the stringer, and the flat or bottom seat cut where the stringer rests on the bottom floor.
Can you see that these lines are simply a "riser line" and a "phantom" tread? The vertical plumb cut of the staircase is simply a line that is the final riser! The bottom seat cut is simply the top of a tread if your basement floor were another tread in a very long staircase.
Are you starting to see that this job is not as hard as it appears at first blush? Setting The Square on the Stringer A typical framing square has two different sized legs. Not only are they different lengths, they are different widths. The tongue of a square is the thinner blade usually 1. The tongue is almost always 16 inches long while the body is 24 inches in length. For stair construction, you orient the square so that the riser measurement will be on the tongue and the tread on the body.
Look at Figure 1. See how the square is placed on the stringer? The 90 degree corner hangs out over the edge. The ruler part of a square always starts at this outside corner and the inch marks proceed each direction out towards the end of each leg.
In our previous example 7.
Find the right tread and rise for your outdoor steps
In other words, use the inside rulers of the square or the outside rulers of the square. NEVER mix them up. Don't use the outside ruler on the tongue and the inside ruler of the body! This implies that the increase of the tread corresponds to a reduction of the riser and vice versa.
According to studies by the French architect the effort of raising the foot is vertically double that to move horizontally; given a length of about 64 cm for a comfortable pace on horizontal levelit can deduce that the tread depth of the step must be the result of the subtraction of said length of twice the value of the riser, ie: Where a is the value of the riser and p is the value of the tread.
Here is a short example. To cover cm height with a riser of 17 cm the following calculation is made, as mentioned in the previous step, to determine the number of steps: Multiplying the number of steps by the 28cm tread you obtain the plan of the staircase: For stairs that have the handrail, the safety regulations stipulate that it should have a height between 90 cm and 1 m and a minimum distance of 4 cm from the wall.
The railing placed on the void must have a minimum height of 1 m and beimpraticable by a 10cm diam sphere DM. It is commonly accepted that poles must be vertical and not horizontal to avoid the dangerous "ladder effect". What types of stairs? After seeing the rules for correct planning, we can proceed with knowing the types of staircases existing. The most widely used because most comfortable. Consisting of two parallel ramps at angle, and an intermediate landing. Very often, the two ramps are connected by steps in a fan shape, to make the most of the space.
It can be circular, square or elliptical.
The steps are anchored to a supporting structure, said plug or column, fixed to the floor and ceiling. Mariner or staggered treads: