House construction starts with the creation of project. Of course, you can choose one of the typical finished options. However, it is not just an ordinary residential building, but your house, so you should think about its individuality, comfort and compliance with the requirements of the owners. Besides, the result of your efforts must please the house owners for many years— mistakes made in designing and building, can “backfire” more than once. The easiest way is to order all drawings from the professional architect and be sure that everything is calculated correctly. However, such work may cost you a lot of money, which you will require during the construction.
What is better?
One of the ways to make the house building less costly but consider the taste and preferences of its owners is to use one of the typical model projects of the wooden house as a basis and try to modify it so that it meets your individual requirements.
Of course, it will require some additional calculations to introduce necessary changes and amendments in the ready design drawings, but this task is not so difficult, and you can do such work on your own. For example, you need to build a beautiful and comfortable porch. What is the best way to do it?
We must mention another feature of the porch construction. Before you start planning, you should choose the material for the steps. If they are expected to be tiled, you must consider size and shape of tiles and width of seams in the calculation. If this work is not done, you’ll have to face parts of steps with narrow strips. Thus, you will accumulate the unnecessary waste of facing material.
What should you take into account when calculating the size of the porch?
Principal dimensions of the parts of the structure you should know are the parameters of the tread and riser. Tread is a horizontal part, on which the person who goes up or down the stairs places his/her foot. Riser is a vertical component of the step. However, speaking of the height of the step (especially for the wooden porch), you should also consider the width of the plate (which means that you must not speak about the size of the riser but find out the lifting (the sum of the riser and the width of plate). After figuring out the height of lifting, you should calculate the dimension of the riser and the plate depending on the materials used and the requirements for the strength of the porch. However, you should do it when creating the details of the future construction.
Comfort and safety
Comfort and safety are the main and priority requirements for the porch of your house.
These qualities are closely related: if climbing the stairs is uncomfortable, there is a risk to stumble and get injured. You must proceed from such preconditions when making calculations.
Lifting height should vary between 120 and 200 mm. Otherwise, it will be uncomfortable and even hard to go up the stairs. In this case, the optimal size is 150–165 mm.
All the steps must have the same height. If for some reason you have to build uneven risers, make sure that the height difference between them doesn’t exceed 5 mm. The tread must equal 280-300 mm so that the person can place a foot on it. You shouldn’t make the steps wider, otherwise you’ll have to make too big steps.
In wooden stairs, each next step should slightly “hang” over the previous one. So that the person doesn’t stumble when climbing the stairs, this canopy must not protrude on more than 20 mm. When calculating the size of tread and riser, you shouldn’t feature this feature of structure in the formulas. Add it to the tread later, when calculating the size of the stair components.
Calculate the size of the step
To build the right and safe staircase, you should make some basic calculations, for example:
- The length of step of the common person is about 600 mm. The sum of double step height (SH) and tread (T) must correspond to this length (L):
2 SH + T = 600 mm.
- Sometimes, to facilitate the calculations, you should substract the optimal height from the length of step in advance:
SH + T = 440 mm.
However, later you should use the first formula. Optimal angle of elevation is 30 degrees. If the angle of elevation (A) is determined, you can calculate the height of the step and tread according to these formulas:
- SH = L sin A
- T = L cos A
And on the contrary, knowing SH and T, you can determine the angle of elevation according to this formula:
- У = arctg(SH/T)
It is possible that for technical reasons, you will have to choose the other angle of elevation, distinct from 30 degrees. The size of steps for some option of elevation angles are given in the following table:
|Height of step (SH), mm||Tread (T), mm||Angle of elevation|
|150 mm||300 mm||26,6º|
|160 mm||280 mm||29º|
|170 mm||260 mm||33º|
|180 mm||240 mm||37º|
|190 mm||220 mm||41º|
|200 mm||200 mm||45º|
It is not recommended to build the stairs with a slope that exceeds 45º: it is almost a limit value. With bigger angle, going up and down the porch can be uncomfortable and even traumatic.
Now, let’s use these data for calculating our project. The top of the porch must be 1–2 cm lower than the floor and 2–3 cm lower than the foundation of the door leaf. And the bottom of construction must correspond to the level of sidewalk, on which you will come to the house. In this way, you can determine the overall height of the porch.
Let’s suppose that the height of our porch is 650 mm. The necessary lifting height is 150 mm. It means that the number of steps is 4 (divide 650 mm by 150 mm and discard the fractional part). But 150 mm multiplied by 4 will give only 600 mm. You can evenly divide the remained 50 mm between all steps, increasing the height of each one is 12.5 mm.
As a result, the height of one step will be 162.5 mm.
Don’t be afraid of fractions! After all, the measurements and accuracy of manufacturing the components will still have some error (and obviously not tenth of a millimeter). So, at the calculation, you can round the height to an integer. Therefore, we can stop on the height of 162 mm.
Let’s calculate and consider the length of the porch
The length of porch is obtained by multiplying the number of steps by the width of tread (without the width of “hanging” part). You will have to add the size of upper platform to this value: it must be no less than the width of the door leaf, as you will not retreat down the stairs to open the door. According to the fire safety rules, the door of the house must open outwards, and you shouldn’t “save” on your own health and life.
If the length of porch turned out more than it is technically possible for this house, you can try to make the steps higher and make all calculations again. But remember that climbing too high on the stairs can turn out uncomfortable and even dangerous. Here you will try to go up and down a lot of times. So, you should consider the angle of elevation, and if it turns out more than 40º, it is better to shift the entrance door and reconsider everything.
New house is almost a new life. Experience and skills are as important for building it as the desire to please the people living here. Therefore, you must know how to build the steps for the porch.
If you have already built the entrance to the house, you can help others. Tell less experienced builders what difficulties you have faced and how you solved these problems.