2016 ncc changes for mid-rise timber buildings · • detail of 2016 ncc provisions • sprinklers...

2016 NCC Changes for

Mid-rise Timber Buildings

Alastair Woodard

WoodSolutions

Contents

• Brief background & summary of new 2016 NCC Changes to the DTS Provisions that now allow Mid-rise Timber Buildings

• Detail of 2016 NCC Provisions

• Sprinklers

• Fire Protected Timber

• Non-combustible Insulation

• Cavity Barriers

• Other Important NCC Requirements

• Further WoodSolutions Resources

NCC 2016 – A Game Changer

The National Construction Code (NCC) is the regulatory framework for determining the minimum design and construction requirements for buildings in Australia.

NCC Volume 1 the Building Code of Australia

Class 2 to Class 9 Buildings

is the document relevant to mid-rise timber buildings

(hereon referred to simply as the NCC)

NCC Compliance Pathways

Two pathways are available under the NCC to demonstrate performance

Image of new WS Design Guide

NCC 2016 – Proposal for Change: Timber Construction

Prior to NCC 2016, timber construction systems in Australia have been restricted to 3 storeys under the Deemed-to-Satisfy(DTS) provisions with higher buildings requiring an ‘Alternative Solution’ pathway for compliance purposes.

Project: Forte LivingBuilder: Lend LeaseLocation: Docklands ,Melbourne

Project :: Ruskin St TownhousesArchitect :: Marcus O’Reilly ArchitectLocation :: Elwood, VICPhotographer :: Dianna Snape

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No Sprinklers With Sprinklers

Maximum Storey Height for Timber DTS Buildings - 2013

NCC 2016 – Proposal for Change: Timber Construction

Globally, many countries now allow construction of timber systems

well above 3 storeys.

Source: TDA NSW

NCC 2016 – New Timber Construction Provisions

The 2016 NCC, has been amended to now allow under the Deemed-to-Satisfy (DTS) provisions the use of fire-protected timber construction systems in

Class 2 (apartments),

Class 3 (eg hotels) and

Class 5 (offices) buildings

up to 25 metres in effective height (herein termed ‘mid-rise construction’).

Mid-rise

Rise in

storey

Type of Construction

Class 2 Class 3 Class 5 Class 6 Class 9a Class 9b

Apartments Hotels Office Shops Healthcare Schools &

public

buildings

4 or more A A A A A A

3 A A B B A A

2 B B C C B B

1 C C C C C C

Maximum Timber Storey Height by Building Classification (BCA 2014)

Low-rise

Maximum Timber Storey Height by Building Classification (BCA 2016)

Mid-rise

Major New Opportunity

• O

Apartments (Class 2) eg Hotels (Class 3) Office Buildings (Class 5)

• A major new opportunity for a wide range of timber products and systems

Mid-rise Apartment Project

Location: British Columbia

Photo: Geoff Stringer

Project: Wood Innovation Design Centre

Location: British Columbia

Architect: Michael Green

In Brief - New DTS Provisions

• The new DTS provisions cover both

• traditional ‘lightweight timber framing’ and

• new ‘massive timber systems’ such as cross laminated timber (CLT)

Lightweight timber framing

CLT

Fire resistant plasterboard

and consist of the use of appropriate layers of fire resistant plasterboard – to provide‘fire- protected timber’ - and the use of compliant automatic sprinkler systems.

Key Issues - Fire & Sound Protection

• A range of factors need to be considered as part of the design of these types of construction, but particularly the key issues of: fire protection and sound attenuation.

Appropriate fire-resisting construction is critical to

providing acceptable levels of fire safety

Sound insulation is important because of its daily impact on

the quality of life.

NCC Changes for Timber Construction

Summary of NCC Changes for Timber Construction

Provide in Section A General Provisions, Part A1 Interpretations, new definitions

in Clause A1.1 Definitions for Fire Protected Timber and Massive Timber

Add to Section C Fire Resistance,Part C1 Fire Resistance and Stability

a new clause- Clause C1.13 Fire Protected Timber: Concession to deem fire-protected timber non

combustible subject to appropriate controls

Provide in Section A General Provisions a new Specification A1.1 Fire Protected Timber defining the required

performance of fire protected timber and method of verification with deemed to satisfy plasterboard solutions

Amend Section C Fire Resistance , Specification C1.1 Fire-resisting Construction, Clauses 3.1 Type A Fire Resisting Construction

and 4.1 Type B Fire Resisting Construction to permit the use of fire-protected timber

subject to appropriate controls in list of concrete and masonry elements

Provide to Section C Fire Resistance a new Specification C1.13 Cavity

Barriers for Fire Protected Timber defining locations and required

performance of cavity barriers to address risk of spread through

cavities

6 major

clause

changes or

inclusions


Provide in Section A General Provisions, Part A1 Interpretations,

new definitions in Clause A1.1 Definitions for Fire Protected Timber

and Massive Timber




Provide in Section A General Provisions a new Specification A1.1 Fire Protected Timber defining the

required performance of fire protected timber and method of

verification with deemed to satisfy plasterboard solutions

We will look at this in more detail

shortly




Add to Section C Fire Resistance, Part C1 Fire

Resistance and Stability a new clause- Clause C1.13

Fire Protected Timber: Concession to deem fire-protected timber to be

non-combustible subject to appropriate controls



Clause C1.13 - Controls









Amend Section C Fire Resistance , Specification C1.1 Fire-resisting

Construction, Clauses 3.1 Type A Fire Resisting

Construction and 4.1 Type B Fire Resisting Construction

to permit the use of fire-protected timber subject to appropriate controls in lieu of

concrete and masonry elements









Amend Section C Fire Resistance , Specification C1.1 Fire-resisting Construction, Clauses 3.1 Type A Fire Resisting Construction

and 4.1 Type B Fire Resisting Construction to permit the use of fire-protected timber

subject to appropriate controls in list of concrete and masonry elements

Provide to Section C Fire Resistance a new

Specification C1.13 Cavity Barriers for

Fire Protected Timber defining locations and required performance

of cavity barriers to address risk of spread

of fire or smoke through cavities

Clause C1.13 – Summary of Controls

Relevant NCC Sections

The NCC classifies buildings into 10 Classes:

Class 1 - Residential

Class 2 - Flats, Units, Apartments

Class 3 - Hotels, Motels,

Class 4 - Class 5,6,7,8,9 Residence

Class 5 - Offices

Class 6 - Shops

Class 7 - Storage, Car Parks

Class 8 - Factories, Workshops, etc

Class 9 - Public Buildings

Class 10 - Outbuildings

These are the three Classes specifically affected by the new NCC changes for mid-rise timber framed construction

Defined in Section A, Part A3, Clause 3.2

DTS Solution for MRT Buildings – Building Classes

http://www.woodsolutions.com.au/Resources/mrtfc-multi-residential-classes

http://www.woodsolutions.com.au/Resources/mrtfc-multi-residential-classes

http://www.woodsolutions.com.au/Resources/MRTFC-buildings

http://www.woodsolutions.com.au/Resources/MRTFC-buildings

Sprinklers

Design of Mid-Rise Timber Buildings

Automatic sprinkler suppression systemto suppress a fire before the timber structure is threatened which greatly reduces the fire risk to people and property.

DTS Solution for MRT Buildings - Sprinklers

High Success Rate:

BRANZ - sprinkler reliability may range from 95% -

98%; the higher value also reported being supported

by the US National Sprinkler Association.

BRANZ, 2000, Fire Protection for High Rise Buildings,

a report prepared by BRANZ, March 2000

Fire Protected Timber


Fire-protected timberUse of fire-grade plasterboard to prevent or delay ignition of the timber structural members,

Fire-grade plasterboard

Timber framing

in the low probability event of sprinkler

failure, so that the response to an

enclosure fire will be similar to

non-combustible elements,

(i.e. masonry or concrete) during the

growth period and prior to fire brigade

intervention.

DTS Solution for MRT Buildings – Fire Protected Timber

NCC 2016 – Fire Protected Timber Requirements

The NCC defines fire-protected timber as fire-resisting timber building elements that comply with the new Specification A1.1.

NCC 2016 – FPT: General Requirements

Specification A1.1 Clause 2.1 applies the following general requirements to fire-protected timber:

In Summary:• the building element must be

protected to achieve the required Fire Resistance Level (FRL); and

• have a non-combustible fire-protective covering applied to the timber which achieves a Resistance to the Incipient Spread of Fire (RISF) of not less than 45 minutes when tested in accordance with AS1530.4.

NCC – Fire Terminology

Fire Resistance Level (FRL)

Resistance to the Incipient Spread of Fire (RISF)

In order to adequately specify or check evidence of compliance of fire-protected timber three other items of information are required :

Results from a non-combustibility test

NCC – Fire Terminology - FRL

Fire Resistance Level (FRL) NCC Part A1.1 Definitions

Integrity –ability of an element of construction to resist the passage of flames

and hot gases from one space to another

Structural adequacy –ability of a loadbearing element to support an

applied load

Insulation –ability of the surface of an

element of construction, on the non-fire side of the element, to maintain a temperature below

the specified limits

Fire testing of a ceiling system

NCC – Fire Terminology - RISF

Resistance to the Incipient Spread of Fire (RISF)

The Resistance to the Incipient Spread of Fire (RISF) in relation to a fire-protective covering means:

‘the ability of a covering to insulate voids and the interfaces with timber elements so as to limit the temperature rise to a level that will not permit ignition of the timber and the rapid and general spread of fire throughout any concealed spaces’.

The performance is expressed as the period in minutes that the covering will maintain a temperature below the specified limits

NCC Part A1.1 Definitions

NCC – Fire Terminology - RISF

The primary objective for the specification of RISF is to

reduce the risk of the timber structural elements being ignited prior to burn-out of the contents or fire brigade intervention; in the unlikely event of failure of the automatic fire sprinkler system.

Fire protective lining

Timber

Stud

NCC – Fire Terminology : Type of Construction

NCC Volume 1, Section C, Part C1, Table C1.1 designates the Type of Construction based on the Class of Building and the Rise in Storeys

Mid-rise Class 2 and 3 (residential) buildings are typically 4 storeys or more high and are

therefore required to be of Type A construction

Fire Protected Timber Requirements: Class 2&3

Having determined the Type of Construction for the building, it is now possible to determine the Fire-Protected Timber requirements for various wall, floor, ceiling and other building elements.

Fire Protected Timber Requirements - General

FRL & RISF General Requirements for Timber Framed Mid-Rise Class 2 & 3 Buildings

FRL Typically90/90/90

for loadbearing

walls & floors

RISF Typically

45 min forwallsand

floors

Fire Protected Timber Requirements - Massive

FRL & MRISF Requirements for Massive Timber Framed Mid-Rise Class 2 & 3 Buildings

FRL Typically90/90/90

for loadbearing

walls & floors

MRISF Typically

30 min forwallsand

floors

NCC 2016 – Concession for Massive Timber

The rationale for the “concession” for massive timber is that subject to maintaining the required FRL, the consequences of ignition of timber structural members are significantly reduced because:

• timber with a large cross-section can achieve high fire resistance levels due to the formation of a char layer

FRL and RISF or MRISF Requirements

• For Class 2 & 3 residential buildings this is typically:

• General Requirements: FRL 90/90/90 and an RISF of 45min

• Massive Timber: FRL 90/90/90 and an MRISF of 30min

• For Class 5 Office buildings

• General Requirements : FRL 120/120/120 and an RISF of 45min

• Massive Timber: FRL 120/120/120 and an MRISF of 30min

NCC 2016 – FPT: General Requirements

For General Requirements (eg. Lightweight framing) Specification A1.1 Clause 2.1 (B) deems

2 layers of 13mm fire-protective grade plasterboard

achieve an RISF45:NC fire-protective covering, must

also meet the required FRL.

Fire-Protected Timber – Lightweight Timber

General Timber (High level of protection to timber)

• Fire-grade plasterboard linings required (typical solution):

• 2 x 13mm fire-grade plasterboard for walls, and

• 2 x 16mm fire-grade plasterboard for ceilings (FRL requirement)

Fire-grade plasterboard

Timber framing

• FRL lightweight timber-framed construction

e.g. 90, 120, 140 x 45mm

Fire Protected Timber

Massive Timber Systems

NCC 2016 – FPT: Massive Timber

The NCC permits a relaxation to the general requirements for fire-protected massive timber providing both the following additional criteria are satisfied:

• the timber panel is at least 75mm thick; and

• any cavity between the surface of the timber and the fire-protective covering or between timber members is filled with non-combustible materials.


Specification A1.1 Clause 2.2 applies the following requirements for fire-protected timber where the timber is massive timber:

A relaxation to the ‘general requirements of Clause 2.1

In Summary:• the building element must be protected to

achieve the required FRL; and• have a non-combustible fire-protective

covering applied to the timber which achieves a Modified Resistance to the Incipient Spread of Fire (MRISF) of not less than the values stated in Table 1 INTERFACE TEMPERATURE AND MINIMUM FIRE-PROTECTIVE GRADE PLASTERBOARD THICKNESS.


Specification A1.1 Table 1 INTERFACE TEMPERATURE AND MINIMUM FIRE-PROTECTIVE GRADE PLASTERBOARD THICKNESS :

For Massive Timber Specification A1.1 Clause 2.2 Table 1 deems 1 layer of 16mm fire-protective grade

plasterboard for ‘All other applications’ achieves the required FRL of the element and an equivalent performance to an MRISF30:NC fire-protective covering.

Fire-Protected Timber – Massive Timber

Massive Timber (Lower level of protection to timber)

• Fire protective covering required:• Element with appropriate layers

of fire protective covering, generally 1 layer of 16mm fire-grade plasterboard for walls and ceilings

Fire -grade plasterboard

Massive timber

• Minimum 75mm thickness of massive timber element, with required FRL, with no concealed spaces between plasterboard coverings and timber

e.g. CLT, Glulam, LVL

Non-Combustible Insulation


This requirement is stipulated in the NCC under Part C1 Fire Resistance and Stability, Clause C1.13 Fire protected timber, subsection (d).

DTS Solution for MRT Buildings – Non-combustible Insulation

Common Insulation Products

Flammability of an insulation product depends on the level of organic

content, with inorganic materials generally less flammable

Common insulation products in the market include:• Cellulose: 70-80% recycled paper (naturally

flammable)

• Polyester: made out of polyester fibres including recycled plastic bottles

• Fibreglass/glasswool: up to 70% recycled glass

• Mineral wool: volcanic rock, melted & spun into fibres

Not all insulation

products are

non-combustible

Non-Combustible Insulation

Typical non-combustible solutions include mineral fibre or glasswool insulation with very low

organic binder contents.

It is important to check that Evidence of Suitability in the form of a current AS 1530.1 report from a NATA registered testing

authority is available for the specific products selected.

Cavity Barriers


The NCC now contains a new Specification C1.13 Cavity Barriers for Fire Protected Timber

DTS Solution for MRT Buildings – Cavity Barriers

NCC 2016 – Cavity Barriers for Fire Protected Timber

Cavity barriers as described in the NCC are

SOU 1 SOU 2

SOU 3 SOU 4

SOU 5 SOU 6

barriers placed in concealed spaces, formed within the perimeter of fire-protected timber building elements that comply with specification C1.13; to limit the spread of fire, smoke and hot gases to other parts of the building.

NCC Requirements

Spec C1.13 defines where cavity barriers must be located

NCC 2016 – Cavity Barriers Required Positions

Cavity barriers are required at the following positions:

Junctions between fire-resisting floor /ceiling assemblies and fire resisting internal walls.

Junctions between fire-resisting floor /ceiling assemblies and fire resisting external walls.

NCC 2016 – Cavity Barriers Required Positions

Cavity barriers are required at the following positions:

Horizontal barriers must be provided at each floor level up to a maximum distance of 5m crs.

Junctions between fire-resisting walls and external walls.

Vertical barriers must be provided in walls up to a maximum distance of 10m crs.

Around the perimeters of door and window openings in fire-resisting construction.

Cavity Barriers

Cavity Barriers Must be installed

in all required locations

Floor/Wall Junction

External Brick Veneer Wall

Roof Space

Windows

DtS Solution for Mid-rise Timber Buildings

• If, the building or building part is Class 2, 3 or 5.

• the building has an effective height of not more than 25m;

• and utilises:

• sprinkler system to Spec E1.5

• fire-protected timber to Spec A1.1

• non-combustible insulation

• cavity barriers to Spec C1.13

Then it meets the DtS Solution for Mid-rise Timber Buildings

Summary of NCC

Controls

Other NCC Requirements

Other NCC Requirements

• Structural Performance

• Acoustic Performance

• External Cladding: non-combustibility, thermal, resistance to water penetration

• Termite Resistance & Durability

WoodSolutions:Assistance &Resources

New Technical Guide No 37 detailing the NCC DtS

requirements for lightweight and massive systems in

Mid-rise Timber Buildings

WS Design Guide 37: New DtS Requirements

New video based education resource detailing the DTS requirements for lightweight and massive systems

WS: On-line Education Resource

WoodSolutions Campus

WoodSolutions technical staff (engineers, architects) on the ground to provide face-to-face assistance to building professionals in getting new timber buildings specified and constructed

WS Mid-rise Advisory Team – Vic Pilot

www.woodsolutions.com.au

2016 NCC Changes for Mid-rise Timber Buildings

Thank you

for your attention

2016 ncc changes for mid-rise timber buildings · • detail of 2016 ncc provisions • sprinklers...

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