Definitions & Terminology

- Eaves are BASIX calculations

What is BASIX• What is BASIX ? BASIX is the Building Sustainability

Index. It is a web-based planning tool that is designed to assess Water, Thermal Comfort and Energy performance of a new home, extension or swimming pool (over 40 000 Litres).

• • Who needs a BASIX Certificate? A BASIX Certificate is

required on all new single dwellings, dual occupancy, villas, townhouses and multi-units in NSW. A certificate is also required for alterations and additions over $50 000 and swimming pools at or over 40 000 Litres

Types of EavesBoxed Eaves

Eaves Trimmers also called Soffit Bearers

AS 1684 Allowable Methods

Soffit Bearers Minimum Sizes

Types of EavesOpen Eaves

Types of EavesOpen Slat Eaves

Types of EavesRaked Eaves

Types of EavesFlush Eaves

Flush Eaves

• Saves Cost– Scaffold– Material– Labour

• Problems – IF Gutter Fails– Water Runs Down Walls– Pools Formed at Footings– Causing Erosion, Swelling

Rafter 90 x 45Ridge 125 x 19

Eaves Width

1. Eaves on plans are usually measured from external walls

OverhangPlan usually from external wall

Always Confirm

In This case 740mm from internal wall

Rafter 90 x 45Pitch 25⁰

Drop OffDistance From Top Plate to Bottom of Overhang

Rafter 90 x 45Pitch 25⁰

Calculating Drop OffSTEP 1 Calculate the RISE of Hatched Triangle

Rafter 90 x 45Pitch 25⁰

Calculating Drop OffSTEP 1 Calculate the RISE of Hatched Triangle

450mm x Tan 25⁰ = 210mm

Rafter 90 x 45Pitch 25⁰

Calculating Drop OffSTEP 1 Calculate the RISE of Hatched Triangle450mm x Tan 25⁰ = 210mm

STEP 2 Add Birdsmouth

210 + 33 =

Rafter 90 x 45Pitch 25⁰

Calculating Drop OffSTEP 1 Calculate the RISE of Hatched Triangle450mm x Tan 25⁰ = 210mm

STEP 2 Add Birdsmouth

210 + 33 = 243

Rafter 90 x 45Pitch 25⁰

Remember Overhang Usually Specified From External Wall but Calculated For

Back of Birdsmouth

What is the Drop OffCavity = 40mBrick = 110mWhat is the Drop Off

Rafter 90 x 45Pitch 25⁰

Drop Off

Rafter 90 x 45Pitch 25⁰

Drop Off

Remember to allow for min 12mm Clearance

Rafter 90 x 45Pitch 25⁰

Its Possible to have a Varying Drop Off

Hazards

• Fall from Heights• Contact with Live Electrical Wires• Materials, Tools falling From Heights• Scaffold Collapse or Toppling over• Dust

• Complete Safe Work Method Statement

Cutting FC Sheeting

• Fibro Cutters• Score & Snap Knife• Grinder with Diamond Blade (Dust Mask

Required)

Estimating

Step 1- Calculate Number of Soffit Bearers

12500 / 600 = 20.83 = 21 +1 = 22 x2= 44

44 x 0.6 x 5% = 44 x 0.63

Fixing Plate 2 @ 12.5

No. LengthSoffit Bearers 70 x 35 F5 44 0.630 27.720 27.900 1.90$ 53.01$

Wall Plate 70 x 35 F5 2 12.500 12.600 25.200 1.90$ 47.88$

Cost Order

Item Section Size Material Linear Total Linear Rate / lm

Note – In this case as waste has been added already we don’t take the individual bearers up to the next 300mm as there will be to much waste.

Estimating

Step 2- Calculate Fascia

Length + Verge O/H = (12.5 + 2 x 0.600) x 1.05 = 14.4 x 2

No. LengthSoffit Bearers 70 x 35 F5 44 0.630 0.900 39.600 1.90$ 75.24$

Wall Plate 70 x 35 F5 2 12.500 12.600 25.200 1.90$ 47.88$ Fascia 190 x 25 H3 FJ 2 14.400 14.400 28.800 7.00$ 201.60$

Cost Order

Item Section Size Material Linear Total Linear Rate / lm

Estimating

Step 3- Calculate Barge Board

Barge Run = Half Span + Eaves Width + Fascia + Gutter+ Plumb Cut + Waste

= (3450+600+25+200+tan 25 x190) x 1.05

No. LengthSoffit Bearers 70 x 35 F5 44 0.630 0.900 39.600 1.90$ 75.24$

Wall Plate 70 x 35 F5 2 12.500 12.600 25.200 1.90$ 47.88$ Fascia 190 x 25 H3 FJ 2 13.700 13.800 27.600 7.00$ 193.20$

Barge Board 190 x 25 H3 FJ 4 5.046 5.100 20.400 7.00$ 142.80$

Cost Order

Item Section Size Material Linear Total Linear Rate / lm

Estimating

Step 4- Soffit Lining

Soffit = 2 x Length + 4 x Barge

= 2 x 12500 + 4 x 4804

= 44.216 x 1.05(5% Waste) = 46.43 / 2.4(Sheet Length) = 19.34 = 20 Sheets

No. LengthSoffit Bearers 70 x 35 F5 44 0.630 0.900 39.600 1.90$ 75.24$

Wall Plate 70 x 35 F5 2 12.500 12.600 25.200 1.90$ 47.88$ Fascia 190 x 25 H3 FJ 2 13.700 13.800 27.600 7.00$ 193.20$

Barge Board 190 x 25 H3 FJ 4 4.806 5.100 20.400 7.00$ 142.80$ Soffit Lining 600 FC 20 2.4 x 0.6 5.00$ 100.00$

Cost Order

Item Section Size Material Linear Total Linear Rate / lm

Estimating

Step 5- Joining Mould

20 Sheets

21 Joins x 0.6 = 12.6 x 1.05 (5% Waste) = 13.23/2.4= 5.5 = 6 Lengths

No. LengthSoffit Bearers 70 x 35 F5 44 0.630 0.900 39.600 1.90$ 75.24$

Wall Plate 70 x 35 F5 2 12.500 12.600 25.200 1.90$ 47.88$ Fascia 190 x 25 H3 FJ 2 13.700 13.800 27.600 7.00$ 193.20$

Barge Board 190 x 25 H3 FJ 4 4.806 5.100 20.400 7.00$ 142.80$ Soffit Lining 600 FC 20 2.4 x 0.6 5.00$ 100.00$ Joining Strip H Mould 6 2.400 2.400 14.400 1.58$ 22.80$

Cost Order

Item Section Size Material Linear Total Linear Rate / lm

Estimating

Step 6- Quad

2 x Building Length + 4 x Verge length (Rafter Centreline) + 8 x Quad (Mitred)

2 x 12500 + 4 x 3806 + 8 x 19 = 40 376 x 1.05 (5% Waste)= 42 395

No. LengthSoffit Bearers 70 x 35 F5 44 0.630 0.900 39.600 1.90$ 75.24$

Wall Plate 70 x 35 F5 2 12.500 12.600 25.200 1.90$ 47.88$ Fascia 190 x 25 H3 FJ 2 13.700 13.800 27.600 7.00$ 193.20$

Barge Board 190 x 25 H3 FJ 4 4.806 5.100 20.400 7.00$ 142.80$ Soffit Lining 600 FC 20 2.4 x 0.6 5.00$ 100.00$ Joining Strip H Mould 6 2.400 2.400 14.400 1.58$ 22.80$

Quad 19 x 19 H3 FJ 1 42.395 42.600 42.600 1.17$ 49.84$

Total 631.76$

Cost Order

Item Section Size Material Linear Total Linear Rate / lm