Eave Quantities
Calculating material quantities for Eaves depends on your method of constructing Eaves, the type of Eave, and the Soffit material requirements.
There are Generally 4 components of Eave material that quantities are calculated for;
Fascia Material - which includes the Fascia and Barge requirements for the job, and in addition if metal Fascia is used corner joiners and brackets must also be allowed.
Eave Bearer - this can vary greatly depending on your method of construction (Simple or Traditional), Eave Bearers are the frame work that the Eave Soffit material is fixed to.
Soffit material - Fibrous Cement sheeting is generally used, however Eave Soffit can be anything from Decking boards to Metal sheeting, Calculating Soffit material quantity also includes joiner or joint strip to be used.
Storm Mould - this will also vary greatly depending on the type of Eave (Boxed or Open) and position of openings as Storm Mould is not required where windows are positioned against the Eave Soffit
There are Generally 4 components of Eave material that quantities are calculated for;
Fascia Material - which includes the Fascia and Barge requirements for the job, and in addition if metal Fascia is used corner joiners and brackets must also be allowed.
Eave Bearer - this can vary greatly depending on your method of construction (Simple or Traditional), Eave Bearers are the frame work that the Eave Soffit material is fixed to.
Soffit material - Fibrous Cement sheeting is generally used, however Eave Soffit can be anything from Decking boards to Metal sheeting, Calculating Soffit material quantity also includes joiner or joint strip to be used.
Storm Mould - this will also vary greatly depending on the type of Eave (Boxed or Open) and position of openings as Storm Mould is not required where windows are positioned against the Eave Soffit
Calculating Fascia material
|
Calculating Fascia material for "Fascia" is simply determining the Perimeter length of the roof, this is done by adding the eave width (where required) to the length of each external wall, however any wall that forms an internal corner does not require the addition of the Eave Width as the Fascia length will be the same as the wall length, an allowance for joins in the Fascia must also be added (allow 1 join per corner) and the number of joins along the Fascia will depend on the lengths of Fascia material that you intend to use i.e. where an 11.000m Fascia length is made up of 6.000m Lengths of Fascia 1 join will be required centrally along the Fascia, therefore 3 joins must be allowed, the amount you allow depends on the thickness of the Fascia material but it is generally accepted that 100mm per join is a good allowance.
Calculating Fascia material for "Barge" is based on the Barge "Run" multiplied by the "True Length of Common Rafter per metre run" for the roof, in many cases this is achieved by adding the half Span to the Eave Width and allowance for "Plumb Cut and Barge tail" (the Barge tail is the part of the Barge that extends past the Fascia to cover the end of the gutter) then multiplying by the "TLCR/m Run" for the roof, and again joins must be allowed the same as for Fascia. Once the Eave and Barge lengths are determined, it is advisable to round each length up to the next 0.300m increment, then all of the Fascia and Barge quantities are added together to determine the number of "Orderable lengths" required for the job (Timber Fascia is supplied in certain "Orderable Lengths" but metal Fascia can generally be Ordered to Length required. |
The Fascia/Barge Quantity Calculator is available on the Fascia Calculations Premium Content page (Purchase Premium page Now)
|
Calculating Eave Bearer Quantity
|
Eave Bearer Quantity is generally calculated by dividing each Fascia Length by the Eave Bearer spacing, Eave Bearer Spacing is determined by the Soffit material requirements and the site "Wind Rating" i.e. a Soffit material that requires a 600mm Eave Bearer spacing for a site with a low "Wind Rating" is likely to require an Eave Bearer spacing less than 600mm for a site with a high "Wind Rating" and it is also likely that additional Eave Bearers will be required at the external corners of the Eaves due to being exposed to greater wind forces.
Where Soffit material requires closer spacing's of Eave Bearers at external corners, it is advisable to calculate the number of Eave Bearers by using the smaller Eave Bearer spacing, this will ensure that enough material is ordered. Eave Bearer Quantity is calculated by Dividing each Fascia length by the required Eave Bearer spacing then round up and plus 1, the number of Eave Bearers is totalled for the job The Length of Eave Bearer is equal to the Eave Width on the Plan plus 100mm (allowance for fixing Eave Bearer to frame), However it important to note that Eave Widths shown of a building Plan are measured from the frame to the inside of the Fascia with one exception, and that is where the building is Brick Vaneer Construction where the Eave Width is measured from the Brick wall to the Fascia, this means that the "Actual Eave Width" is the Eave Width shown on the Plan plus the Width of Brick and Cavity. The Eave Bearer quantity is then calculated by Totalling the number of Eave Bearers for the job multiplied by the Eave Bearer Length to determine total Lineal metres of material, this is then divided by the preferred Orderable Length to determine the number of orderable Lengths required. Calculating Eave Bearers for Gable of Skillion "Eave Overhang" is Calculated the same way except the Fascia length is based on the Rafter Length not the Plan length. |
The Eave Bearer Quantity Calculator is available on the Eave Bearer Calculations Premium Content page (Purchase Premium page Now)
|
Calculating Soffit material Quantity
|
Calculating Eave Soffit material Quantity is generally done by first dividing the sections of Eave on the Plan into the "into over" method, this is generally done by marking the Building Plan starting at the top left corner of the building and marking sections as "into over" working clockwise around the Plan, what this generally means is that each Eave Length will be the length of the external wall plus one Eave Width with the exception for walls that form an internal corner (as previously mentioned).
Then each Eave section is divided by the Length of your preferred eave sheet size to determine the number of sheets required for each section (it is recommended that you round up to half or full sheets as necessary, this ensures enough material is ordered). The number of Eave sheets for each section is then totalled to determine the number of Eave sheets that are required for the Job. Joint strips/Joiners/Cover battens can be calculated at the same time as the number of Eave sheets for each Eave section, as you will require one Joint strip/Joiner/Cover batten per sheet for each Eave section (where the number of eave sheets are part sheets such as half sheets, round up the number to a whole number for calculating the number of Joint strips/Joiners/Cover battens). The length allowed for each Joint strip/Joiner/Cover batten will be the Width of the Eave Soffit material which will generally be the "Actual Eave Width" dimension. Then number of Joint strip/Joiner/Cover battens for each section are then totalled then multiplied be the "Actual Eave Width" to determine the total lineal metres required then divided by the Preferred Joint strip/Joiner/Cover batten Length to determine the number of Joint strip/Joiner/Cover batten Orderable lengths are required for the job. Calculating Soffit Sheet for Gable of Skillion "Eave Overhang" is Calculated the same way except the Eave section length is based on the Rafter Length not the Plan length. |
The Eave Soffit Material Quantity Calculator is available on the Soffit Sheet Calculation Premium Content page (Purchase Premium page Now)
|
Calculating Storm Mould Quantity
|
Calculating Storm Mould material for Eaves is simply determining the Perimeter length of the Building, this is determined directly off the Plan and is the length of each external wall, an allowance for joins in the Storm Mould must also be added (allow 1 join per corner) and the number of joins along the Storm Mould will depend on the lengths of Storm Mould material that you intend to use i.e. where a 9.000m Storm Mould length is made up of 4.800m Lengths of Storm Mould, 1 join will be required centrally along the Storm Mould, therefore 3 joins must be allowed, the amount you allow depends on the depth of the Storm Mould material but it is generally accepted that 100mm per join is a good allowance.
Calculating Storm Mould material for "Eave Overhang" at a "Gable end" or "Skillion end" is based on the Barge "Run" multiplied by the "True Length of Common Rafter per metre run" for the roof, in many cases this is achieved by adding the half Span and Eave Width (if applicable) then multiplying by the "TLCR/m Run" for the roof, and again joins must be allowed the same as previously mentioned. Once the Storm Mould lengths are determined, it is advisable to round each length up to the next 0.300m increment, then all of the Storm Mould quantities are added together to determine the number of "Orderable lengths" required for the job. Note: if windows are positioned against the Eave Soffit it will be necessary to deduct some of the width of the window opening from the quantity of Storm Mould as only a small Storm Mould return is required at each side of the opening, and if the Eave is an Open Eave it will be necessary to add extra Storm Mould to trim around each Rafter. |
The Storm Mould Quantity Calculator is Free for Members
(Go to Calculator Now) |