Therma TT47

Therma T27 T47 Wedge

Tapered Insulation To Enhance Water Drainage From Flat Roofs

Kingspan Therma TT47 is a tapered high performance, fibre-free rigid thermoset insulation, faced on both sides with a coated glass tissue autohesively bonded to the insulation core during manufacture.

  • FM approved for Class 1 steel deck roof assemblies
  • Insulation and drainage in one
  • LPCB approved to LPS 1181: Part 1
  • Easy to handle and install

Product Information

Product Data table
Specification Guide
Testing and Data Table
Product Dimensions 1200 mm x 1200 mm (1.44 m²)
Product thickness Systems with a 1:30 & 1:40 fall: 50 mm minimum
Systems with a 1:60 & 1:80 fall: 25 mm minimum
Systems with a 1:120 fall: 30 mm minimum*
All systems: Unlimited maximum*
Taper Gradients Falls of 1:30, 1:40, 1:60 and 1:80**

*Packer boards will be required above a specific thickness.
**For information regarding tapered roof designs incorporating 
Kingspan Therma TT47 in a wider range of falls please contact the Kingspan Insulation Technical Service team at
The effective thermal conductivity and thermal resistance of the insulation in a tapered roofing system is specific to the individual roof design. The Kingspan Insulation Tapered Roofing Department performs calculations to determine these values in accordance with Annex C of BS EN ISO 6946: 2007 (Building components and Building elements – Thermal resistance and thermal transmittance – Calculation method) as part of the scheme design process. 
he roof insulation shall be Kingspan Therma TT47  ____ mm thick, comprising a CFC/HCFC-free and zero Ozone Depletion Potential (ODP) rigid thermoset insulation core with coated glass tissue facings on both sides, manufactured under a management system certified to BS / I.S. EN ISO 9001:2008, BS / I.S. EN ISO 14001:2004 and BS / I.S. OHSAS 18001:2007 by
Kingspan Insulation Limited and shall be installed in accordance with the instructions issued by them.

A Project Specific Warranty provided by Kinspan Insulation must be submitted.

Management Standards

Standard Management System
BS / I.S. EN ISO 9001:2008 Quality Management
BS / I.S. EN ISO 14001:2004 Environmental Management
BS / I.S. OHSAS 18001:2007 Health and Safety Management

Kingspan Therma TT47 is also manufactured to the highest standards in accordance with the requirements of:
Requirement Rigid polyisocyanurate (PIR) and polyurethane(PUR) products for building end–use applications
BS 4841-3 Specification for laminated boards (roofboards) with auto–adhesively or separately bonded facings for use as roof board thermal insulation under built–up bituminous roofing membranes
BS 4841-4 Specification for laminated boards (roofboards) with auto–adhesively or separately bonded facings for use as roofboard thermal insulation under single−ply roofing membranes

Spanning On Metal Decks

Trough Opening (mm) Minimum Insulant Thickness (mm)
≤75 25
76 - 100 30
101 - 125 35
126 - 150 40
151 - 175 45
176 - 200 50
201 - 225 55
226 - 250 60

Product Testing

Characteristic Standard Result
 Compressive Strength AS 2498.3 Typically exceeds 150 kPa at 10% compression
Water Vapour Resistance AS 2498.5 > 7 MN·s/g·m 

Fire Performance

Kingspan Therma TT47, when subjected to the British and Australian Standard fire tests specified in the table below, will achieve the result shown, when waterproofed with a single–ply waterproofing membrane.
Test Result
BS 476-3: 2004
(External fire exposure roof test) 
Dependent on single-ply membrane adopted
AS 1530.3
(Ignitability, Flame Spread, Heat Release, Smoke Release)
Spread of Flame Index: 1
Smoke Development Index: 5
AS 2122.1
(Flame Propagation AS 1366)

Kingspan Therma TT47, when subjected to the British Standard fire test, specified in the table below, will achieve the result shown when waterproofed with 3 layer built–up felt and a loading coat of 10 mm chippings. For specifications without the chippings please consult the manufacturer of the mineral surfaced cap sheet for their fire classification details.
Test Result
BS 476-3: 2004 FAA Rating

Further details on the fire performance of Kingspan Insulation products may be obtained from the Kingspan Insulation Technical Service.

FM Certification

Kingspan Therma TT47 are certified as achieving Class 1 Insulated Steel Deck Pass to Factory Mutual Research Standards 4450 (Approval Standard for Class 1 Insulated Steel Deck Pass) and 4470 (Approval Standard for Single–Ply, Polymer–Modified Bitumen Sheet, Built–Up Roof (BUR) and Liquid Applied Roof Assemblies for use in Class 1 Non-combustible Roof Deck Construction), subject to the conditions of approval as a roof insulation product for use in Class 1 roof constructions as described in the current edition of the Factory Mutual Research Approval Guide.

LPCB Certification

Metal deck roofing constructions incorporating Kingspan Therma TT47, produced at Kingspan Insulation’s Pembridge and Castleblayney manufacturing facilities, have been successfully tested to LPS 1181: Part 1 (Requirements and Tests for Built–up Cladding and Sandwich Panel Systems for use as the External Envelope of Buildings). 

Do you need help and advice on your project?

If you have questions related to our products, or is seeking technical advice for your project, our customer care team is ready to help.

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Contact Us

Kingspan Insulation New Zealand

We're ready to help. For any enquiries, call 0800 1 23 23 1 or send an email to

666 Great South Road

Level 3, Building 10,

New Zealand

Ellerslie, Auckland

0800 1 23 23 1

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