Kosourav
Aug 16, 2019 News
As you know, kosour – this beam, which is the backbone of the ladder. By Kosourov fixed level. Usually Kosourov is two. Of course, in principle, may be enough, and one (for narrow stairs), but in practice, as a rule, if the width a flight of stairs exceeds 2,5 meters, on the contrary, adds a third kosour center. Some figures: the load on the ladder is not less than 250 kg and with a useful width of the stairway up to 1 m thick Kosourov of wood should be at least 50 mm, with a width of up to 1,25 m – no less than 60 mm and a width of 1,5 m – not less than 70 mm. Dimensions Kosourov metal selected size rolling molded products capable of withstanding bending the specified load plus the weight of the ladder steps and fence stairs. Reinforced concrete Kosourov usually manufactured industrial method (monolithically with stairs). The thickness of the treads also depends on the width of the stairway.
For stage length 800 mm (1000 mm, 1200 mm) should use a board thickness of 40 mm (50 mm, 60 mm, respectively). Generally, it is considered as follows: the thickness of the tread width refers to the march of 1 to 20. In this case, of course, a deviation from this proportion is only possible in the direction of increasing thickness treads. Before manufacture treads boards should be carefully ostrogany and ground. For wood for risers, such requirements are not presented (no risers are a must for manufacture of stairs). Handrails and stair railings of staircases are made from high appropriate timber (especially prone to abrasion rails). Stair railings must be not less than 900 mm in size.
Tags: construction and repair
