Celotex FAQs

Energy Performance Certificates (EPCs) are now required, by law, on all new homes. EPCs will become mandatory in October 2008 on all buildings, whenever they are built, sold or rented out.

An EPC is a measure of the energy efficiency of a building as well as the environmental impact as measured by CO₂ emissions. The EPC provides 'A' to 'G' ratings for the building, with 'A' being the most energy efficient and 'G' being the least efficient. To date, most buildings will be either a 'D' or 'E' rating , with those built to the 2006 building regulations typically achieving a 'B' rating.

An EPC will provide a Recommendation Report that offers advice and suggestions on how to further improve energy efficiency. This will ultimately have a positive impact on reducing CO₂ emissions.

For homes that are intended to be marketed 'off-plan' a Predicted Energy Assessment (PEA) is required. This is simply the predicted energy performance and environmental impact (CO₂) from SAP calculations carried out at the design stage. PEAs do no include a Recommendation Report, unlike EPCs.

Upon physical completion of the Building, an EPC will be required to either give to the buyer or to continue with the sale of the completed property. The EPC will then replace the PEA in Home Information Packs (HIPs).  

We implement an environmental policy that pledges our commitment to minimise negative impacts on the environment, whilst adhering to the principles of sustainable development.

All Celotex boards have zero ozone depletion potential and have recently been independently assessed by the BRE. With the lowest environmental impact score, lowest carbon footprint and broadest product offering, Celotex is proven to be the most sustainable PIR product solution.

For our Sustainability Statement or to view our BRE Environmental Profiles, please refer to the Sustainability page of the website.

Yes. They contain glass fibre core reinforcement, almost entirely made from recycled waste glass. About 90% of the aluminium in our foil facers comes from recyclable sources. Polyester polyols used in our boards can be produced from waste sources such as PET bottles used for fizzy drinks.

Yes, the technology exists. However, with typical building life in excess of 50 years and our foam boards having been launched in the late 1970s, there is insufficient feed-stock available to make any commercial recycling venture viable at present. Nonetheless, Celotex boards can be safely disposed of.

The embodied energy arising from our manufacturing process is extremely low because the chemical reaction is exothermic.

Our latest cardboard packing line requires considerably less process energy than shrink wrapping and doesn't use oil-based plastics.

We only offer shrink-wrap packaging on products requiring protection from rain while stored on site. Most boards feature banded cardboard packaging, which is easily recycled, and is biodegradable, minimising pollution from careless disposal.

We have been established for over eighty years and also introduced PIR insulation boards to Europe. Thus we have been able to maintain a considerable technical advantage. No one else can begin to match our pioneering achievements in product performance, in-depth knowledge of manufacturing techniques and unsurpassed technical support.

Drawing on our unrivalled PIR board manufacturing experience, we employ a special chemical formulation and unique production techniques that result in boards with superior reaction to fire performance.

To download our comprehensive Environmental Information Sheet and our Sustainability Statement, please refer to our 'Literature' pages.

Our boards fully conform to BS EN 13165 - the harmonised standard for determining reaction to fire. Many achieve D2 classification. No known competing PIR products have obtained D2 status without additional protection such as plasterboard. Celotex meets the classification when directly exposed to flame!

Yes. Another exclusive feature of most of our boards is the incorporation of long-strand reinforcing glass fibres within the PIR foam core. This aids dimensional stability and further improves behaviour when exposed to a fire.
In addition, the blowing agent used in the manufacture of our boards is a better insulator than air while still having zero ozone depletion properties with low global warming potential.

There are many different reasons, but perhaps the most compelling one is our boards' low thermal conductivity - the exceptionally slow rate at which heat passes through them. This facilitates relatively thinner, lighter, less costly roof, wall and floor constructions that easily meet tough modern insulation legislation standards.

CE marking confirms that our products fully comply with BS EN 13165 and that key performance characteristics have been verified through independent type testing.

This is a very clear method of confirming that delivered products match your actual specification. Competitors that don't CE mark cannot match this level of transparency.

Yes. The company is quality assured to BS EN ISO 9001: 2000, confirming a robust and fully audited factory production control system.

It is staffed by seasoned construction professionals and has justly earned a very high reputation for the speed and depth of assistance available.

We can provide U-value calculations for all product applications, SAP ratings for dwellings and advice on any aspect of product selection, including compliance with building regulations.

Polyurethane (PUR) is made by the polymerisation of an isocyanate resin to create a plastic material with a wide range of beneficial properties.

Reacting the isocyanate (polymeric methyl diphenyl isocyanate or MDI) with certain types of polyol, such as a polyether, creates a tough but rigid plastic material.

Polyisocyanurate (PIR) is an improved type of rigid polyurethane.

The production process creates strong isocyanurate linkages in the molecular structure. Chemical breakdown of the foam occurs at higher temperatures than PUR, so it is much more difficult to ignite.

True polyisocyanurate foam contains about 50% or more isocyanurate linkages.

Just about anything...

• Car seats, dashboards and bumpers
• Soft furnishings. sanding blocks
• Thermal insulation boards, pipe insulation, refrigerator and deep freezer cabinets
• Shoe soles
• Adhesives for lamination
• Flotation tanks and safety equipment

The list just goes on and on...

Almost exclusively for thermal insulation, especially for use in buildings.

Fire safety for building occupants is an important design consideration. Materials that are more difficult to burn are generally preferable.

Polyisocyanurate foam combines polyurethane benefits, such as rigidity, lightweight and thermal efficiency, with the key addition of lower flammability.

Most manufacturers of PUR boards can produce polyisocyanurate-modified foams.

However, Celotex is uniquely able to make very high 'index' foams in laminated board form, satisfying the ISO definition (over 400 index).

High Index foams satisfy the requirements of major fire insurers, so ensure you specify 'PIR foam to ISO standards'.

Degradation of PIR commences at a higher temperature than PUR. A fire would need to be much more seriously developed before PIR foam might significantly contribute to the spread of the fire through a building.

PIR also forms a surface char, helping to insulate the underlying foam from the fire.

It is made by a lamination process, formed between aluminium foil facings that are glued together in a continuous laminator, where the 'adhesive' is a mixture of MDI and polyol. An added blowing agent causes this adhesive to expand into foam that hardens and is cut into manageable board sizes.

• It's lightweight, stiff and can span widely
• It's efficient: thickness for thickness there's no more efficient insulant
• It's difficult to ignite
• It's durable and gives reliable energy savings throughout a building's normal lifetime
• It is safe to use, emits no noxious/hazardous fumes and can be safely disposed of or recycled
  
  

PIR foam is an extremely effective insulant. Used appropriately, it will contribute to significant reductions in energy consumption and carbon dioxide emissions.

That is good for the environment.

Please see our Sustainability Statement in the 'Literature' pages for more details.

It is more expensive off the shelf than cheaper insulants like mineral fibre loft insulation, but usually the same price as a polyurethane board.

However, PIR boards reduce the usable space loss in buildings They also require less costly mechanical fixings and don't need supporting materials to hold them in place.

Celotex has manufactured thermal insulation boards in the UK for over eighty years. The brand is very well known throughout the construction industry and is supported by a nationwide network of leading distributors and builders merchants.

Visit our Stockists page and discover the outlets nearest to you.

Target U values for domestic buildings in England and Wales are 0.2 W/m2K in roofs insulated at rafter level, 0.16 W/m2 in roofs insulated at horizontal ceiling level, 0.3 W/m2K in walls and 0.22 W/m2K in floors.

In Scotland there is a two tier system according to the efficiency of the boiler.

For oil boilers with a minimum SEDBUK rating of 85%, natural gas boilers with a rating of 78% and LPG boilers with a rating of 80% the requirements are as above with the exception of flat roofs and floors where the requirement is 0.25 W/m2K.

For boilers below those ratings, the requirements are 0.18 W/m2K in roofs insulated at rafter level, 0.16 W/m2K in roofs insulated at horizontal ceiling level, 0.27 W/m2K in walls and 0.22 W/m2K in flat roofs and floors.

SEDBUK is the Seasonal Efficiency of Domestic Boilers in the UK.

For a SAP ( Standard assessment Procedure ) calculation, all details of a new dwelling are required: areas and U values of each element minus window areas; window areas; U value of glazing and orientation; details of the central heating system and controls (including method of providing hot water and storage if applicable); number of flues and intermittent extractor fans and so on.

A SAP questionnaire can be downloaded to expand on these requirements.

Celotex is not suitable for use in inverted roofs (protected membranes) as it must remain dry at all times.

No. When used in ground floors, Celotex must always be above the damp proof membrane (DPM ).

No. Celotex is a partial fill cavity insulation requiring a cavity of a minimum 25mm clear or 50mm clear if NHBC or Zurich insurance are providing a warranty, or if the site is considered unduly exposed by the Local Authority.

Celotex can be used below the damp proof course (DPC) providing there is a clear cavity. If there is any likelihood that it will be in wet conditions, it should be protected by a  damp proof membrane (DPM). Similarly if the cavity is backfilled with a concrete weak mix ,Celotex should be protected.

No. Downlighters should not be recessed into insulated ceilings as they penetrate the vapour control layer (VCL) and act like a flue, drawing warm moist air into the roofspace where it condenses and drips back out of the fitting, possibly causing a fire risk.

If downlighters are to be used, they should be fitted in a false ceiling below the structural ceiling.

The global warming potential (GWP) of Celotex is 3 and this is below the threshold figure of 5.

We do not recommend the use of Celotex beneath a raft foundation.

Cold bridging is caused when an element with low thermal performance penetrates an insulated element of a building, for example a concrete balcony cantilevering through an external wall.

An R value of 0.75m2K/W is required to avoid the bridge, this can be achieved using our Celotex T-Break board TB3020 which achieves 0.85m2K/W. This needs to be fitted above and below the concrete into the building by 1500mm, as that length of concrete also achieves better than 0.75m2K/W.

Celotex is not suitable directly below floor tiles. A screed is required to spread the load and prevent movement between the tiles.

No. Electrical cables should not be channelled into Celotex as that would reduce the performance of the Celotex.

Cables can penetrate through Celotex and if cables are laid between two layers of Celotex they should be oversized to cope with any increase in operating temperature.

Celotex has no detrimental effect on the cable sheathing.

Celotex FF3000 and GA3000 have the same thermal efficiency.

FF3000 products are more dense with a safe uniformly distributed load (UDL) of 140kN/m2 whereas GA3000 has a 120kN/m2 UDL.

FF3000 is recommended for use in floors beneath a screed, particularly where underfloor heating is proposed.

Insulating between and over flat roof joists is not an accepted method of construction.

When insulating between roof joists there must be a minimum 50mm ventilated cavity above the insulation.

Celotex is expected to remain efficient for the life of the building, and the Lambda values published have been prematurely aged in accordance with British Standards.

Celotex cannot be used as a cavity barrier alone but it can pass by a cavity barrier. In other words, the cavity barrier needs to be between the Celotex and the outside leaf.

You are allowed 25% of the floor area as glazing plus any windows covered by the proposal if applicable.

It is possible to compensate for excessive glazing by overinsulating in the walls, roof and floor.

You can calculate this yourself and advise us of the target U-values required to compensate which we will address, or we can make those calculations for you but there is a fee payable for that service.

A polythene membrane on top of Celotex below a screed or concrete oversite performs three tasks: it acts as a VCL; it prevents migration of the screed / concrete which can force the boards apart leaving cold spots in the floor; and (most importantly) it prevents a reaction between the wet screed / concrete and the foil facer of the Celotex which can cause a reaction whereby the Celotex is burnt and gases are given off leaving weak pockets in the screed / concrete.

Celotex at a minimum of 20mm thick can be used as a cavity closer around window and door openings.

Celotex is classed as combustible when tested in accordance with BS476 and has a class 1 surface spread of flame when tested to the same standard.

The specific heat capacity c_p states how much heat energy is required to increase the temperature of 1kg mass of a material by 1K. Specific heat capacity c_p is measured in J/(kg·K).

More heat energy is required to raise the temperature by 1K of a material with a greater heat capacity. And inversely, less energy is required to produce a 1K increase in temperature in materials with lower heat capacities.

Calculated values of specific heat capacity c_p of various materials
Material Specific heat capacity c_p = J/(kg·K)

• Rigid polyurethane foam (PUR/PIR) 1400 – 1500
• Wood-fibre insulation boards 1400
• Mineral wool 1030
• Wood and wood-based materials 1600
• Plasterboard 1000
• Aluminium 880
• Other metals 380 – 460
• Air (ρ=1.25 kg/m³) 1000
• Water 4190