Stridor is a sign of upper airway obstruction. In children, laryngomalacia is the most common cause of chronic stridor, while croup is the most common cause of acute stridor.Generally, an inspiratory stridor suggests airway obstruction above the glottis while an expiratory stridor is indicative of obstruction in the lower trachea. laryngeal web, cyst or laryngocele may present with stridor, usually at birth or soon after. Laryngotracheobronchitis (Viral Croup) . The most common cause of acute stridor in childhood is laryngotracheobronchitis, or viral croup.
The load in the floor beam is then transferred to the main load carrying system, such as a longitudinal plate girder. Per Article 9.8.3.1 of the AASHTO LRFD (5 th Edition, 2010), the deck plate is to act as a common flange of the ribs, the floor beams, and the main longitudinal components of the bridge.
You will need a roof beam as a nailing surface to support the rafters. Typically, the roof beam is made by nailing together a few pieces of dimensional lumber. Once again, you will need to look at your local charts and use your local snow load factor to determine the maximum span for a given wood rafter size. The table below shows built up beams for 31.3 psf of snow loading.