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Questions and Answers

Dricon & ATP Generic fire retardant treatments for plywood

Below are just some of the regular questions we get asked about our fire retardant treatments. Should you need more detail from the answers supplied or have other questions, please contact Creffields on 0118 945 3533 or email us info@creffields.co.uk

 

1. What is the difference between DRICON and ATP Generic fire retardant treatments?

2. What are Euroclasses and why are they replacing the old Class 1 / Class 0 standards?

3. Are these new Euroclasses as good as the old Class 1 / Class 0?

4. How many new Euroclass Classifications are there for fire performance and which are relevant to plywood?

5. Can I achieve 30 or 60 minute fire resistance with Lonza fire retardant treatments?

6. Building Control want evidence that the fire treated plywood I am supplying will be Euroclass B / Euroclass C compliant. What documentation do I need?

7. Is CE Marking of fire retardant treated plywood required?

8. Can T & G plywood be fire treated?

9. My customer has a specification that asks for a FR3 fire retardant treatment. What does this mean?

10. Does DRICON or ATP Generic treatment alter the appearance of fire treated plywood?

11. What are the benefits of factory controlled impregnation treatments over brush/spray surface applied FR coatings?

12. If fire treated plywood is cut on-site does it need any extra protection?

13. Can you fire treat veneered plywood?

14. Do I need to increase my material wastage allowance to take into account changes in plywood properties after FR treatment?

15. Modern school building projects use plywood extensively. Are the Lonza Wood Protection fire retardant treatments suitable for these types of projects?

16. Can Lonza fire retardant treatments be applied to plywood for use IN London Underground projects?

 

 

 

 


1. What is the difference between DRICON and ATP Generic fire retardant treatments?

DRICON is a water-based, type HR (Humidity Resistant) fire retardant impregnation treatment.

Dricon treatment has the ability to remain very stable in the treated plywood even at high humidity levels.

It is suitable for all interior applications including areas of high humidity e.g wall & ceiling linings both decorative & non-decorative, flooring, in a roof & in stairwells. 

Dricon is the only fire treatment in the UK to hold BBA Agrement certification.

It is fully approved for use in London Underground & in the rail industry due to its low smoke properties.

ATP Generic is a water-based, type DI (Dry Interior) fire retardant impregnation treatment. It is suitable for dry interior use & temporary works e.g. general construction works, temporary flooring, temporary hoarding, exhibition work & shop fitting.

Both ATP Generic & Dricon fire treatments are applied by Lonza Wood Protection at Lonza's own treatment facility at Castleford, West Yorkshire under controlled conditions in a high pressure impregnation plant, commonly followed by kiln drying to return the plywood to an acceptable or specified moisture content.

 

 


 

2. What are Euroclasses and why are they replacing the old Class 1 / Class 0 standards?

In line with the Construction Products Regulation, introduced in July 2013, plywood used in permanent construction is now treated to either Euroclass B or  Euroclass C in line with the requirements of the Harmonised Product Standard for Plywood - EN13986.

Class 1 & Class 0 are now obsolete. Euroclass B has replaced Class 0 and Euroclass C has replaced Class 1.

A Euroclass test measures flame spread, heat release, fire growth rate & smoke emission.

A Euroclass Classification for any given plywood species is awarded in accordance with the requirements of EN 13501-1 (Fire Classification of Construction Products and Building Elements).

 

 


 

3. Are these new Euroclasses as good as the old Class 1 / Class 0?

The simple answer is that the new Euroclasses are underpinned by more up-to-date test methods compared to the old British Standards of Class 1 & Class 0 and trying to compare old and new is the wrong approach.

Class 1 involved a measure of the Surface Spread of Flame (SSF).

Class 0 included a measure of SSF and heat release.

The Euroclass SBI test measures a wider scope of fire critical factors than the old Class 1 /0 tests, namely spread of flame, heat release, fire growth rate & smoke levels. EUROCLASSES ARE MORE ROBUST

 

 


 

4. How many new Euroclass Classifications are there for fire performance and which are relevant to plywood?

The Euroclass system applies to other materials not just plywood.

Untreated plywood would achieve a Euroclass D when tested. Lonza treatments can upgrade ply to either Euroclass B or Euroclass C as required.

Typical products Euroclass Euroclass test requirements
Totally inorganic products made from stone, concrete, bricks, ceramics, glass or steel A1

EN ISO 1182 
EN ISO 1716

Products as Euroclass A1 but containing not more than 1% by weight or volume (whichever is the lower) of homogeneously distributed organic material. Gypsum boards, mineral wool A2 EN ISO 13823
EN ISO 1182
EN ISO 1716
Gypsum boards with thin surface linings. Highest possible level for fire retarded wood products. Cement-bonded particle board ≥ 10mm thick B EN 13832 (SBI)
EN ISO 11925-2 (SFI)
Gypsum boards with thick surface linings. Fire retarded wood products C EN 13832 (SBI)
EN ISO 11925-2 (SFI)
Untreated wood products with a thickness ≥ 5mm and density of ≥ 400 kg/m3. Plywood and OSB ≥ 9mm thick D EN 13832 (SBI)
EN ISO 11925-2 (SFI)
Untreated wood products with a density of < 400 kg/m3. Low density fibreboard.
Plastic-based insulation
E EN ISO 11925-2 (SFI)
Untested products F No requirements 000000000000000000000

 

 

 

 

 


 

5. Can I achieve 30 or 60 minute fire resistance with Lonza fire retardant treatments?

In short - NO

Fire resistance is a time related concept (30 or 60 mins) & commonly refers to the ability of a material or item to resist the passage of fire e.g. a 30 minute fire door will resist burn through for a minimum period of 30 mins.

Both DRICON and ATP Generic are fire retardant treatments that target the initial stages of a developing fire.

They retard the growth/propagation of the fire by limiting the amount of heat generated, retarding the flame spread, the overall fire growth rate and limiting smoke production in line with Building Regulation requirements.

A EUROCLASS FIRE RETARDANT TREATMENT DOES NOT PROVIDE A TIME RELATED FIRE PERFORMANCE

 

 


 

6. Building Control want evidence that the fire treated plywood I am supplying will be Euroclass B / Euroclass C compliant. What documentation do I need?

Lonza Wood Protection issues a Fire Treatment Certificate upon despatch of an order which itemises the customer name and order details. Generally this is what is presented to Building Control.

A species/thickness specific Euroclass Classification Report can also be provided for the plywood in question if needed to support an enquiry.

FULL EVIDENCE OF COMPLIANCE = TREATMENT CERTIFICATE + CLASSIFICATION REPORT

 

 


 

7. Is CE Marking of fire retardant treated plywood required?

As part of the Construction Products Regulation, July 2013, all FR plywood sold from stock by any merchant & available the open market to be used in permanent construction MUST be CE marked.

 

 


 

8. Can T & G plywood be fire treated?

 Ply can be fire treated when the T & G’s are already machined, either on 2 sides or all 4 sides. The ply must be kiln dried after fire treatment to ensure the T & G will fit together. Alternatively, full sheets can be processed that can be machined after.

 

 


 

9. My customer has a specification that asks for a FR3 fire retardant treatment. What does this mean?

The UK Wood Protection Association (WPA) has a number of commodity specifications relating to fire retardant treatment. Each of these commodity specifications ONLY classifies the end use which is then used as a guide to select the appropriate fire retardant treatment. THEY DO NOT STATE WHAT FIRE PERFORMANCE OR WHAT FIRE TREATMENT IS NEEDED.

The list of commodity specifications is as follows:

FR1 - Non load bearing dry interior use

FR2 - Load bearing dry interior use

FR3 - Interior use with a Relative Humidity >75%

FR4 - Weather protected exterior use

FR5 - Weather exposed situation

Plywood specifications would generally involve either one of: FR1, FR2 or FR3

 

 

 


 

10. Does DRICON or ATP Generic treatment alter the appearance of fire treated plywood?

As a general rule:

Both DRICON & ATP Generic treated plywood looks slightly lighter than un-treated plywood.

 

ATP Generic: A few residual salts may be seen on the treated  faces & edges of the plywood. Generally these can be removed with a light sand / wipe over.
Some Dricon crystals may be visible on the faces & edges of the treated plywood. Generally these can be removed with a light sand/wipe over.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


11. What are the benefits of factory controlled impregnation treatments over brush/spray surface applied FR coatings?

 

Lonza Wood Protection Factory Controlled Impregnation Treatments:

 

- Are applied within stringent controlled factory conditions.

- Have full traceability of the treatment process.

- Give deep impregnation to all faces

- The treatment cycle used is specific to the type of plywood being treated

 

 


 

12. If fire treated plywood is cut on-site does it need any extra protection?

No additional treatment is required to the cross cut ends of fire treated plywood.

 

 

 


 

13. Can you fire treat veneered plywood?

We do not recommend fire retardant impregnation treatment of pre-veneered plywood. The veneers are prone to blistering / delamination at the point of treatment.

 

 

 


 

14. Do I need to increase my material wastage allowance to take into account changes in plywood properties after FR treatment?

For the majority of species, customers should supply a minimum 5% extra material with each order to allow for kiln degrade, kiln samples and moisture content samples.

 

 

 



 

15. Modern school building projects use plywood extensively. Are the Lonza Wood Protection fire retardant treatments suitable for these types of projects?

DRICON has been widely used to protect interior plywood used in educational projects to provide a tried, tested and trusted long term fire protection.

Click on the leaflet to download.

 

 

 


 

16. Can Lonza fire retardant treatments be applied to plywood for use IN London Underground projects?

Yes, DRICON is fully approved for use in temporary works within London Underground - meeting the requirements of London Underground Standard 1-085 'Fire Safety performance of Materials'. Treatment needs to be to Euroclass B in accordance with EN 13501-1.

Typically hardwood plywood is supplied.

 

 

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