7/28/2019 Cmo calcular el ngulo en las vigas del techo

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Cmo calcular el ngulo en las vigas deltecho

na viga es un soporte estructural para revestimiento de tejas ytechos. Probablemente necesites el ngulo de una viga para varios propsitos. Un techo conpendiente pronunciada, absorbe con mayor fuerza el viento, mientras que una pendiente ms suaveaboserber ms rayos UV. Estos factores pueden afectar la pendiente estructural o clculos deenerga. Puedes calcular los ngulos de una viga triangular con algunas medidas bsicas y clculostrigonomtricos.

Nivel de dificultad:Moderada

InstruccionesNecesitars

Una calculadora cientfica Una cinta mtricaInstrucciones

1. 1Mide la longitud de la base de la viga. La base es el elemento horizontal de la viga paralela al cieloraso de la edificacin. Ahora debers conocer la distancia horizontal desde el borde de la basehasta la punta directamente debajo del vrtice o pico. Llamemos "b" a esta distancia. Para vigassimtricas, esta es simplemente una mitad del largo total de la base.

2. 2Mide la altura de las vigas. Llammosla "h". Esto es simplemente la distancia vertical desde elvrtice hasta su base.

3. 3Calcula el ngulo de la esquina ms baja de la viga. Este es el ngulo hecho por la base y uno delos bordes de la pendiente, tcnicamente conocido como "cordones superiores". Para encontrareste ngulo puedes usar la funcin trigonomtrica de tangente inversa o "arctan". La tangente de unngulo es el borde opuesto dividido por el borde adyacente. Por lo tanto, usando lgebra, la basedel ngulo es igual al arctan (h/b). Si la viga es simtrica, los dos ngulos de la base son iguales. Sino, repite el mismo proceso que usaste para encontrar el ngulo de la base del lado izquierdo paraencontrar el ngulo base del lado derecho.

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4. 4Calcula el ngulo superior de la vida. Usa el hecho de que la suma de los ngulos interiores del untringulo siempre da 180 grados. Si has calculado los dos ngulos de la base, puedes restar su totala 180 para obtener el ngulo de la punta, esto es, el ngulo de la punta es igual a 180 menos elngulo de la base 1 menos el ngulo de la base 2.

Typical Parts of a Roof Truss

A truss is essentially a framed set ofraftersthat supports the roof of your house. A truss offersgreater strength which allows for a much wider span between walls than older traditional framingtechniques. Trusses allow for a wide variety of shapes to be used in designing a roof since they offergreater flexibility. As a bonus most trusses are built from wood which is a renewable resource and isthus an environmentally friendly building technique.

Below you will find the major roof truss components illustrated and briefly defined.

SlopeIs the measure of how "steep" a roof is. For example, if a roof is "4 in 12", the roofrises 4 inches for every horizontal run of 12 inches. The pitch of the roof is a big factor indetermining the kinds of materials that can be used and the longevity of the roof. Usually, a

steeper roof (higher pitch) will last longer due to its better drainage capabilities.

Top Chord - Main member of a truss running along the underside supporting the decking. Bottom Chord - Main member of a truss running along the lower side between supports. Peak The highest part of the truss. Overhang That portion of the roof truss structure that extends beyond the exterior walls of a

building.

Cantilever - a beam anchored at one end projecting into space.Roof Rafters

Information on Roof Rafters

Rafters make up the main framework of all roofs. Rafters rest on the top of the building wall and

are inclined up to meet the ridge or another rafter which they are fastened to. Rafters will be spacedevery 16 - 48 inches depending upon the design of the roof. The rafter will often extend beyond thewall (overhang) which creates the eaves of the building to help protect the siding and windows of thebuilding as well as make sure that water from rain and/or snow will run off the roof farther away fromthe foundation of the house.

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Common Rafters - Common to all types of roofs these beams extend at right angles from theplate to the roof ridge. They are used as the basis for laying out other rafter types.

Hip Rafters - The roof beams that extend from the corner of the plate to the ridge. Valley Rafters - The roof beams that extend from the plate to the ridge along an intersection

between two roofs. (i.e. -cross hip or cross gable roof)

Jack Rafters - See belowo Hip Jack - Roof beam that extends from the plate to the hip raftero Valley Jack - Roof beam that extends from the ridge to the valley raftero Cripple jack - Roof beam that is placed between a hip rafter and a valley rafter. It

does not touch the ridge or the roof or the plate

Roof Slope

Determining Roof Slope

Slope (or pitch) measures the amount of rise your roof has compared to the length. In other words,

for every twelve inches of length your roof will rise a set number of inches. The diagram belowillustrates a roof that has a seven inch rise for every 12 inches of length thus it has a 7 inch slope or

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pitch. (also expressed 7 in 12)

Measuring Slope

An easy way to measure slope is to take level and mark where 12 inches is. (assuming it is longerthan one foot) Place the level with one end on the roof and raise the other end until it is level. Nexttake a tape measure and determine the number of inches between the roof and the spot you havemarked on your level. You now have the amount of slope for your roof.

Simplified Slope

1.

Flat Roof - Flat or with just the slightest amount of a pitch to them.2. Low Slope Roof - Usually around a 2-3 in pitch roof that is easily walkable with normalfooting.

3. Medium Slope Roof - Considered 4-6 in pitch roof, it is walkable with normal footing.4. Steep Slope Roof - Any pitch above 6 in, this is a roof that is not walkable without

assistance.