Specification & BOQ for “OVERDECK ROOF INSULATION SYSTEM -
Loosely Laid” with “INSUBOARD” – Extruded Polystyrene Board”

SCOPE:

This specification covers overdeck insulation system using the “Insuboard” extruded polystyrene thermal insulation boards.

General:

1. The area where overdeck insulation system needs to be installed shall be made free from all other activities that could disrupt the installation of the system.
2. All the products specified in this document shall be installed strictly in accordance with the manufacturer’s written instructions and by a specialist applicator approved by the manufacturer.
3. “INSUBOARD” to be used in the system shall be manufactured by SUPREME PETROCHEM LTD shall meet the key performance properties listed below against each.
4. The applicator shall ensure that the product in the system are received in good condition without damage and stored as per manufacturer’s instructions.

Key properties of the specified products:

​Property	Standard	​Unit	Value
Density	ASTM D 1622	​Kg/m3	​34-36
​Thermal Conductivity	​ASTM C 518-98	​W/m-K	​0.028
​Compressive strength	​ASTM D 1621-95	​Kpa	​≥300
Water Absorption by submersion (28 days)	​ASTM 2842	​% by Volume	≤ 1
Flammability	​DIN 4102 Part 1 UL 723	​Building Material Class	B2 (difficult to ignite)

OVERDECK INSULATIOn - LOOSELY LAID:

Providing and laying Roof insulation treatment with 50 mm thick INSUBOARD, Extruded Polystyrene Board, CFC, HCFC free, co2 based, 34-36 kg density, 0.028 w/m.k thermal conductivity, compressive strength of > 300 kpa and water absorption of 0.2 % by volume. Providing and applying dimpled drainage board of 8 mm height laminated with geotextile for drainage of water and final finishing with loose laid Paver Blocks / Precast Cement Tiles as with complete accessories like multi level drains , accessories etc as per the instruction of engineer in charge.

APPLICATION METHODOLOGY

The RCC roof surface to be provided with proper slope by light weight PCC average 50-75 mm thick.
 
Providing and laying on the sloped Roof a suitable waterproofing system : Polymer Modified Bituminous ( APP/SBS ) or PU or Acrylic or PVC or TPO as per site conditions & requirement.
 
Providing and laying INSUBOARD Extruded Polystyrene Board Insulation 50 mm/75 mm thick, 34-36 Kg/Cum density having a minimum compressive strength of > 300 Kpa and water absorption less than 0.2% by volume. Installation of Insuboard – thermal insulation boards in a staggered Pattern with proper ship lap joints.
 
Providing and laying on the Insuboard board, HDPE dimpled drainage board laminated with geo-textile fabric of 8 mm height for drainage of water. Drainage board to terminated 150 mm on the parapet by suitable, adhesive / flashing.
 
Providing and laying on the drainage layer interlocking precast paver blocks as final finishing and providing pre-fabricated EPDM drain outlets.

Details:

Gola / Fillet to be made at the joint of parapet and roof for suitable termination of waterproofing system.

Budgetary Quotes :

​No.	Description	Unit	Rate	Qty	Amount
1	OVERDECK INSULATION - LOOSELY LAID	​	​	​	​
1.1	Providing and laying on the waterproofing layer Insuboard XPS- Extruded Polystyrene Board Insulation 50 mm thick, 34-36 Kg/Cum density having a minimum compressive strength of > 300 Kpa and water absorption less than 0.2 % by volume.	SQM	0.00	0.00	0.00
1.2	Providing and laying on the insulation layer, HDPE dimpled drainage board of 8mm height laminated with geotextile fabric.	​SQM	​0.00	​0.00	​0.00
1.3	Providing and laying on the drainage layer interlocking precast paver blocks as final finishing and providing pre-fabricated EPDM drain outlets	SQM	0.00	0.00	0.00
-	TOTAL	​	0.00	0.00	0.00

Above rates are indicative and on per sqm basis only.
Taxes, Freight & Overlaps/Wastages will be extra.

MATERIAL - GENERAL DESCRIPTION:

​Extruded Polystyrene boards to be manufactured from General Purpose polystyrene granules though an automated extrusion process free of CFC blowing agents : preferably with a blend of co2 & ethanol : low Global warming index : the boards are 100 % closed cell structure with a unique properties of high compressive strength & a stable thermal conductivity properties over the life cycle of building etc.

APPROVED SYSTEM:

​The boards of size 600mm width x 1250 mm length & 75 mm thickness with shiplaps to be laid in brick patterns over the waterproofing layer already laid over the RCC slab. Over the Insuboard HDPE dimpled arainage board 0f 8 mm height laminated with geo-textile to be laid.

FINISH:

Providing and laying on the drainage layer interlocking precast paver blocks as final finishing and providing pre-fabricated EPDM drain outlets.

THERMAL PERFORMANCE:

The extruded polystyrene over deck insulation system improves the thermal efficiency of the building by reducing the U value as per the prescribed norms in the ECBC codes depending on the type of building  in terms of hours of operations & geographical location. The thermal performance is very stable through out  the life cycle of the building. It improves the thermal comfort & also helps in optimising the loads thereby reducing the capex & operating cost of HVAC systems.

FIRE PERFORMANCE:

​XPS boards must be fully tested in accordance with DIN 4102 part 1 with regard to fire properties, flame spread , & surface burning characteristics . Also suitable Fire stops , sleeves, PU sealant, Rockwool sleeves etc wherever there are electrical cut outs & opening. The boards must be of self extinguishing characteristic etc.