#COLLAR TIES VS RAFTER TIES UPDATE#

The diagram, an example of which is shown to the right, will update dynamically as each of the inputs are set. The first step in using the calculator is to input the overall geometry. Ridge straps are not designed in this module, but may be added to control the uplift separation. However, a ridge strap has no effect upon gravity load scenario of the walls being pushed outward. However, a tie in any position will help in both scenarios.Īlternatively instead of a collar tie, a ridge strap can also be used to keep the rafters from separating at the ridge. A tie located in the bottom third of the roof, usually called a 'rafter tie' (and which may also serve a dual purpose as a ceiling joist), is most efficient in preventing the walls from splaying outwards under downward loading.

Ties prevent the walls from being pushed outwards by the roof under downward or gravity loads.Ī tie located in the top third of the roof, usually called a 'collar tie' or 'collar beam', is most efficient for preventing the rafters from separating at the ridge in uplift loading.

Ties prevent the rafters from separating at the ridge in wind uplift loads and.In the design of a gable roof, ties serve two purposes, as illustrated in the graphic on the right: Using the calculator involves three essential steps, and one optional step in which the design can be fine-tuned. All load combinations are checked, and both uplift and downward forces are considered. The wood roof ties calculator is capable of designing the ties and rafter for a gable roof having any combination of collar ties, rafter ties, or ridge straps. Number and Length of Rafter and Collar ties - Computes the number and length of rafter ties and collar ties based on roof dimensions and spacing.Wood Roof Ties to NDS 2018 - Usage & Theory Guide Using the Module.Number and Length of Rafters - Computes the number and length of rafter boards based on roof dimensions and spacing.Number and Length of Purlins for a Roof - Computes the number of purlins for a roof based on dimensions and spacing.Screws for a Metal Roof - Computes the number of screws needed for a metal roof.Number and Length of Metal Roof Panels - Computes the length and number of metal panels and trim pieces for a metal roof.Roofing nails needed for a roof - Calculates the number of roofing nails needed for a roof in normal and high wind conditions.Shingles needed for a roof - Calculates the number of standard bundles (33.3 ft 2) of shingles for a roof.4x8s needed for a roof - Calculates the number of 4x8 sheets needed to cover a roof.Number of Trusses Needed for a Roof - number of trusses needed based on the roof width and the truss spacing.26.6 o : 6/12) based on the length of the rise and run. Pitch of a Roof - Computes angle of incline in the roof in both degrees and rise over 12' run (e.g.It also returns the number of 4x8 sheets to cover the roof, the number of standard bundles of shingles to cover, and the number of roofing nails for both normal and high wind environments. Area of a Roof - Computes the area of a roof based on the pitch and the dimensions of the area covered by the roof.Metal for a Roof - Calculates the number of metal panels for a roof.This algorithm puts the collar tie two feet below the ridge, but only if the ridge is 48' above the rafter ties. The collar tie length is a function of the pitch of the roof and the position of the collar tie. Note: some builder use a collar tie on every other rafter. Collar ties are suggested for roofs with a rise greater than forty eight inches (48'). Rafter ties or Ceiling Joists keep the rafter boards from kicking out under the downward load on the roof. Collar ties are included when the total rise is above 48'.Consult your local codes for the required material specifications. The choice of rafter boards is 2x4 for rafters shorter than six feet (6'), 2圆s for rafters between 6 feet and 10 feet, and 2x8s for up to 16 foot long rafters.The length of the Ridge is the length of the ridge plate.The rules in this calculator are as follows:

#COLLAR TIES VS RAFTER TIES PROFESSIONAL#

In all cases, confirm your estimates with a professional estimate and adhering to local building codes. The Roof Rafter calculator is meant to help with material estimates. Rafter Boards (RB): The calculator computes the following rafter framing materials: ( oC) On-center rafter spacing (default: 24').INSTRUCTIONS: Choose units and enter the following: It also returns the length of the ridge board, and the length and number of rafter ties and collar ties. The Roof Rafter Count calculator computes the total number of rafter boards (roof joists) for a gabled roof based on the ridge length, pitch and span.

Collar ties vs rafter ties