Kingspan Insulation Kooltherm K5 phenolic external wall board Kingspan Insulation

Kingspan Kooltherm K103

Premium performance rigid Phenolic floor insulation board

Replaces Kingspan Kooltherm K3.

New lower Lambda Value (Thermal Conductivity) 0.018 W/mK... The most thermally efficient commonly used insulating board.

Used for insulating beam and block, concrete, and timber floors with or without underfloor heating systems.

Faced on both sides with a glass tissue based facing, autohesively bonded to the insulation core during manufacture.

Premium performance rigid thermoset fibre-free phenolic insulant manufactured with a blowing agent that has zero Ozone Depletion Potential (ODP) and low Global Warming Potential (GWP).

High compressive strength: 120 kPa

Thicknesses and Availability:

Available in most popular thicknesses from the manufacturer; short lead-times apply as we may need to get the products in from Kingspan before delivering to site.

This Kooltherm Range includes the following readily available product thicknesses 25mm, 40mm, 50mm, 60mm, 70mm, 75mm and 100mm.

The following thicknesses are manufactured to order and may have minimum order requirements: 80mm, 120mm, 130mm and 140mm.


Product Information

General information about Kingspan Kooltherm K103

Product Application

Floor insulating board

Kingspans premium performance 'lower-lambda' value phenolic foam board, Kooltherm K103, is suitable for use in beam and dense block floors, between floor joists, suspended timber ground floors, between and under floor joists, concrete ground based floors, floating ground floors, upgrading concrete slab floors, and garage conversions.

Product Make-up

Core

Kingspan Kooltherm K103 floor board is a premium performance fibre-free rigid thermoset phenolic insulant manufactured with a blowing agent that has zero Ozone Depletion Potential (ODP) and low Global Warming Potential (GWP)

Facings

Faced on both sides with a glass tissue based facing, autohesively bonded to the insulation core during manufacture

Product Properties

Thermal Conductivity 0.018 W/m·K
Compressive Strength 120 kPa at 10% compression. BS EN 826: 2013
Nominal Density 35 kg/m³
Board Length 2.4m
Board Width 1.2m
Board Edge Square
Vapour Resistance > 370 MNs/gm BS EN 12086: 2013

Product Prices

Buy Kingspan Kooltherm K103

The prices and quantity discounts below are 'per pack' rates. Packs contain multiple boards... 12 x 1.2x2.4m = 34.56m² - in this instance, there are 12 x boards in a pack where each board is 1.2m x 2.4m providing a total coverage of 34.56m² per pack.

Rarely requested product sourced directly from manufacturer. Kingspan K103 25mm, 12 x 1.2x2.4m = 34.56m² - ranging from £9.68 to £10.13 per m²

1 x pack @ £10.13 per m² / £29.16 per board = £349.92 (£419.90 inc-VAT) per pack
2 x packs @ £10.04 per m² / £28.90 per board = £346.82 (£416.18 inc-VAT) per pack
3 x packs @ £9.95 per m² / £28.64 per board = £343.73 (£412.48 inc-VAT) per pack
4 x packs @ £9.86 per m² / £28.39 per board = £340.63 (£408.76 inc-VAT) per pack
5 x packs @ £9.77 per m² / £28.13 per board = £337.53 (£405.04 inc-VAT) per pack
6 x packs @ £9.68 per m² / £27.87 per board = £334.44 (£401.33 inc-VAT) per pack

Rarely requested product sourced directly from manufacturer. Kingspan K103 40mm, 8 x 1.2x2.4m = 23.04m² - ranging from £13.18 to £13.79 per m²

1 x pack @ £13.79 per m² / £39.71 per board = £317.64 (£381.17 inc-VAT) per pack
2 x packs @ £13.66 per m² / £39.35 per board = £314.83 (£377.80 inc-VAT) per pack
3 x packs @ £13.54 per m² / £39.00 per board = £312.01 (£374.41 inc-VAT) per pack
4 x packs @ £13.42 per m² / £38.65 per board = £309.20 (£371.04 inc-VAT) per pack
5 x packs @ £13.30 per m² / £38.30 per board = £306.39 (£367.67 inc-VAT) per pack
6 x packs @ £13.18 per m² / £37.95 per board = £303.58 (£364.30 inc-VAT) per pack

Rarely requested product sourced directly from manufacturer. Kingspan K103 50mm, 6 x 1.2x2.4m = 17.28m² - ranging from £14.99 to £15.69 per m²

1 x pack @ £15.69 per m² / £45.17 per board = £271.04 (£325.25 inc-VAT) per pack
2 x packs @ £15.55 per m² / £44.77 per board = £268.64 (£322.37 inc-VAT) per pack
3 x packs @ £15.41 per m² / £44.37 per board = £266.24 (£319.49 inc-VAT) per pack
4 x packs @ £15.27 per m² / £43.97 per board = £263.84 (£316.61 inc-VAT) per pack
5 x packs @ £15.13 per m² / £43.57 per board = £261.44 (£313.73 inc-VAT) per pack
6 x packs @ £14.99 per m² / £43.17 per board = £259.04 (£310.85 inc-VAT) per pack

Rarely requested product sourced directly from manufacturer. Kingspan K103 60mm, 5 x 1.2x2.4m = 14.4m² - ranging from £17.68 to £18.50 per m²

1 x pack @ £18.50 per m² / £53.28 per board = £266.38 (£319.66 inc-VAT) per pack
2 x packs @ £18.33 per m² / £52.80 per board = £264.02 (£316.82 inc-VAT) per pack
3 x packs @ £18.17 per m² / £52.33 per board = £261.67 (£314.00 inc-VAT) per pack
4 x packs @ £18.01 per m² / £51.86 per board = £259.31 (£311.17 inc-VAT) per pack
5 x packs @ £17.84 per m² / £51.39 per board = £256.95 (£308.34 inc-VAT) per pack
6 x packs @ £17.68 per m² / £50.92 per board = £254.59 (£305.51 inc-VAT) per pack

Rarely requested product sourced directly from manufacturer. Kingspan K103 70mm, 4 x 1.2x2.4m = 11.52m² - ranging from £20.54 to £21.49 per m²

1 x pack @ £21.49 per m² / £61.90 per board = £247.61 (£297.13 inc-VAT) per pack
2 x packs @ £21.30 per m² / £61.36 per board = £245.42 (£294.50 inc-VAT) per pack
3 x packs @ £21.11 per m² / £60.81 per board = £243.23 (£291.88 inc-VAT) per pack
4 x packs @ £20.92 per m² / £60.26 per board = £241.04 (£289.25 inc-VAT) per pack
5 x packs @ £20.73 per m² / £59.71 per board = £238.85 (£286.62 inc-VAT) per pack
6 x packs @ £20.54 per m² / £59.16 per board = £236.65 (£283.98 inc-VAT) per pack

Rarely requested product sourced directly from manufacturer. Kingspan K103 75mm, 4 x 1.2x2.4m = 11.52m² - ranging from £22.75 to £23.80 per m²

1 x pack @ £23.80 per m² / £68.54 per board = £274.17 (£329.00 inc-VAT) per pack
2 x packs @ £23.59 per m² / £67.94 per board = £271.74 (£326.09 inc-VAT) per pack
3 x packs @ £23.38 per m² / £67.33 per board = £269.31 (£323.17 inc-VAT) per pack
4 x packs @ £23.17 per m² / £66.72 per board = £266.89 (£320.27 inc-VAT) per pack
5 x packs @ £22.96 per m² / £66.12 per board = £264.46 (£317.35 inc-VAT) per pack
6 x packs @ £22.75 per m² / £65.51 per board = £262.03 (£314.44 inc-VAT) per pack

Rarely requested product sourced directly from manufacturer. Kingspan K103 90mm, 3 x 1.2x2.4m = 8.64m² - ranging from £27.25 to £28.51 per m²

1 plus packs @ £28.51 per m² / £82.11 per board = £246.33 (£295.60 inc-VAT) per pack
3 plus packs @ £28.26 per m² / £81.38 per board = £244.15 (£292.98 inc-VAT) per pack
5 plus packs @ £28.01 per m² / £80.66 per board = £241.97 (£290.36 inc-VAT) per pack
7 plus packs @ £27.75 per m² / £79.93 per board = £239.79 (£287.75 inc-VAT) per pack
9 plus packs @ £27.50 per m² / £79.20 per board = £237.61 (£285.13 inc-VAT) per pack
11 plus packs @ £27.25 per m² / £78.48 per board = £235.43 (£282.52 inc-VAT) per pack

Rarely requested product sourced directly from manufacturer. Kingspan K103 100mm, 3 x 1.2x2.4m = 8.64m² - ranging from £28.57 to £29.89 per m²

1 plus packs @ £29.89 per m² / £86.08 per board = £258.24 (£309.89 inc-VAT) per pack
3 plus packs @ £29.63 per m² / £85.32 per board = £255.96 (£307.15 inc-VAT) per pack
5 plus packs @ £29.36 per m² / £84.56 per board = £253.67 (£304.40 inc-VAT) per pack
7 plus packs @ £29.10 per m² / £83.80 per board = £251.39 (£301.67 inc-VAT) per pack
9 plus packs @ £28.83 per m² / £83.03 per board = £249.10 (£298.92 inc-VAT) per pack
11 plus packs @ £28.57 per m² / £82.27 per board = £246.82 (£296.18 inc-VAT) per pack

Rarely requested product sourced directly from manufacturer. Kingspan K103 150mm, 2 x 1.2x2.4m = 5.76m² - ranging from £43.36 to £45.37 per m²

1 plus packs @ £45.37 per m² / £130.67 per board = £261.34 (£313.61 inc-VAT) per pack
4 plus packs @ £44.97 per m² / £129.52 per board = £259.03 (£310.84 inc-VAT) per pack
7 plus packs @ £44.57 per m² / £128.36 per board = £256.71 (£308.05 inc-VAT) per pack
10 plus packs @ £44.17 per m² / £127.20 per board = £254.40 (£305.28 inc-VAT) per pack
13 plus packs @ £43.77 per m² / £126.05 per board = £252.09 (£302.51 inc-VAT) per pack
16 plus packs @ £43.36 per m² / £124.89 per board = £249.78 (£299.74 inc-VAT) per pack

Limited stock of the most popular boards sizes may be held at some of our larger depots.

Where products need to be brought in from Kingspan, please allow approx. 1 week for delivery on stocked items (highlighted in green below in the properties section) and up to 3 weeks on made to order thicknesses. While Kingspan keep the majority of the popular thicknesses in stock, less popular thicknesses may carry a minimum order level.

Kingspan reserves the right to change stocked products - while we will do all we can to keep on top of changes, availability and lead times my vary.

Please observe the 'Star Rating' indicators to assess availability.
Product Availability Excellent Generally 1 or 2 days for delivery
Product Availability Good Generally 1 to 5 days for delivery
Product Availability Fair Generally 5 to 10 days for delivery
Product Availability Poor Generally 5 to 15 days for delivery
Product Availability Undetermined Please call to check availability and approximate lead times

Product availability depends upon stock levels at closest depot and delivery logistics to geographic locations


Product Performance and Guides

Product Performance, Manufacturer Certification, Downloads, and Installation Guides

Thermal Resistance

While we have provided Thermal Resistance values for all thicknesses on the Kingspan K103 datasheet, some thicknesses may not be readily available.

Items highlighted in green are generally held in stock by Kingspan.

Product Thickness Thermal Resistance kg/m²
Kingspan K103 25mm 25mm 1.35 m²K/W 1.01 kg/m²
Kingspan K103 30mm 30mm 1.65 m²K/W 1.19 kg/m²
Kingspan K103 40mm 40mm 2.20 m²K/W 1.54 kg/m²
Kingspan K103 50mm 50mm 2.75 m²K/W 1.89 kg/m²
Kingspan K103 60mm 60mm 3.30 m²K/W 2.24 kg/m²
Kingspan K103 70mm 70mm 3.85 m²K/W 2.59 kg/m²
Kingspan K103 75mm 75mm 4.15 m²K/W 2.77 kg/m²
Kingspan K103 80mm 80mm 4.40 m²K/W 2.94 kg/m²
Kingspan K103 90mm 90mm 5.00 m²K/W 3.29 kg/m²
Kingspan K103 100mm 100mm 5.55 m²K/W 3.64 kg/m²
Kingspan K103 110mm 110mm 6.00 m²K/W 3.99 kg/m²
Kingspan K103 120mm 120mm 6.65 m²K/W 4.34 kg/m²
Kingspan K103 130mm 130mm 7.20 m²K/W 4.69 kg/m²
Kingspan K103 140mm 140mm 7.75 m²K/W 5.04 kg/m²
Kingspan K103 150mm 150mm 8.30 m²K/W 5.39 kg/m²

Product Certificates

Please visit the Kingspan website for product certificates.

Kingspan Videos

How to install insulation below floor screed
How to install insulation above floor joists, suspended timber floor
How to install insulation below floor joists, suspended timber floor
How to install insulation below floor slab

Solid Ground Floors – Insulation Below Floor Slab or Screed

Below Slab specific
  • The site should be prepared and foundations, where appropriate, built to damp proof course (DPC) level.
  • A thin sand blinding may be used to achieve a continuous level surface free from projections over rolled hardcore.
  • Below Screed specific
  • Concrete slabs should be allowed to dry out fully prior to the installation of the insulation boards (average 1 day per mm of slab thickness).
  • The surface of the slab should be smooth, flat and free from projections. Rough cast slabs should be leveled using a thin sand blinding to ensure boards are continuously supported.
  • General guides for Below Slab or Screed
  • The damp proof membrane (minimum 300 micron / 1200 gauge polythene) should be laid with joints well lapped and folded, to prevent the passage of ground water, over well compacted hardcore or the concrete floor slab, prior to laying the insulation boards.
  • The membrane should be brought up the surrounding foundation walls until it is sufficiently above the height of the wall DPC so that it will connect with or form the DPC.
  • The insulation boards should always be loose–laid break–bonded, with joints lightly butted.
  • If two layers of insulation are required, they should be horizontally offset relative to each other so that, as far as possible, the board joints in the two adjacent layers do not coincide with each other.
  • A strip of insulation board (minimum 20 mm thick) should be placed vertically around the perimeter of the floor in order to prevent cold bridging. The bottom of the strip of insulation board should be level with the top of the floor screed and the bottom should be level with the bottom of the horizontal floor insulation, and closely butted up to it.
  • Insulation boards should be overlaid with a polythene sheet (not less than 125 micron / 500 gauge), to prevent the wet screed / concrete penetrating the joints between the boards, and to act as a vapour control layer. Ensure the polythene sheet has 150 mm overlaps, taped at the joints, and is turned up 100 mm at the walls.
  • For insulation below slab: the subsequent installation of the concrete slab and screed or other flooring material is carried out in a manner similar to that for an un–insulated floor. The concrete slab and screed should be allowed to dry out prior to the installation of the floor finish.
  • For insulation below screed: use sand and cement screed laid to a minimum thickness of 65 mm for domestic construction and 75 mm elsewhere.
  • Kingspan K103 Solid Floor Below Floor Slab
    Kingspan K103 Solid Floor Below Floor Slab
    Kingspan K103 Solid Floor Below Floor Screed
    Kingspan K103 Solid Floor Below Floor Screed

    Beam and Block Ground Floors – Insulation Below Screed

  • Beam and block floors should be level and grouted.
  • The damp proof membrane (minimum 300 micron / 1200 gauge polythene) should be laid with joints well lapped and folded, to prevent the passage of ground water, over the concrete floor slab, prior to laying the insulation boards
  • The membrane should be brought up the surrounding foundation walls until it is sufficiently above the height of the wall DPC so that it will connect with or form the DPC
  • The insulation boards should always be loose–laid break–bonded, with joints lightly butted.
  • If two layers of insulation are required, they should be horizontally offset relative to each other so that, as far as possible, the board joints in the two adjacent layers do not coincide with each other.
  • A strip of insulation board (minimum 20 mm thick) should be placed vertically around the perimeter of the floor in order to prevent cold bridging. The bottom of the strip of insulation board should be level with the top of the floor screed and the bottom should be level with the bottom of the horizontal floor insulation, and closely butted up to it.
  • Insulation boards should be overlaid with a polythene sheet (not less than 125 micron / 500 gauge), to prevent the wet screed penetrating the joints between the boards, and to act as a vapour control layer. Ensure the polythene sheet has 150 mm overlaps, taped at the joints, and is turned up 100 mm at the walls.
  • Use sand and cement screed laid to a minimum thickness of 65 mm for domestic construction and 75 mm elsewhere.
  • Kingspan K103 Beam & Block Floor Below Floor Screed
    Kingspan K103 Beam & Block Floor Below Floor Screed

    Suspended Timber Ground Floors – Insulation Between Joists

    Installation from Above the Floor Joists
  • The installation of Kingspan Kooltherm K103 Floorboard in suspended floor constructions should be carried out before commencement of floor boarding.
  • The insulation boards should be cut to fit snugly between the floor joists. Measure the distance between the joists prior to cutting the boards as spacings can vary.
  • In order to ensure insulation boards are flush with the top surface of the joists, they should be supported on minimum 25 mm x 25 mm treated softwood timber battens, proprietary galvanised steel saddle clips, or galvanised nails partially driven into the side of the joists.
  • Battens / nails should be placed at an appropriate height to suit the thickness of board being fitted, and nails should remain 40 mm proud of the joist.
  • The insulation boards should then be fitted between the joists so that they are supported by the battens / saddle clips or nails.
  • Installation from Below the Floor Joists
  • Floor boards should be fixed over joists prior to fitting Kingspan Kooltherm K103 Floorboard from below.
  • The insulation boards should be cut to fit snugly between the floor joists. Measure the distance between the joists prior to cutting the boards as spacings can vary.
  • Push the cut insulation boards between the joists so they are flush with the underside of the floor boards.
  • Side–nail 25 mm x 25 mm timber battens to the joists or partially drive galvanised nails into the side of the joists in the appropriate position to hold the boards in place.
  • General guides for Above or Below Floor Joists
  • If two layers of insulation are required, they should be horizontally offset relative to each other so that, as far as possible, the board joints in the two adjacent layers do not coincide with each other.
  • All board joints should be tightly butted.
  • Ensure that insulation boards are fitted tightly between joists, and any gaps are filled with expanding urethane sealant.
  • Any narrow gaps between a joist and perimeter wall should be insulated by specially cut pieces of board which in turn should be supported on blocks nailed to the underside of the joists. Gaps less than 25 mm wide should be filled with expanding urethane sealant.
  • Kingspan K103 Suspended Timber Floor Between Joists
    Kingspan K103 Suspended Timber Floor Between Joists
    Minimum order level - £175.00 ex-VAT. For further details on Delivery Charges and Minimum Order levels, please Click Here