01694 751394
01694 751736
Specifying Cast Epoxy Intumescent
The most effective way of approaching this task is to consult Interact Fire Solutions at the earliest possible stage in the design planning process of any construction project.
Interact can advise throughout on this checklist of key considerations:
Material Specifications
There are four major manufacturers who supply the following grades of epoxy intumescent. We work closely with the following two manufacturers:
* International Interchar 212
* Ameron Pitt-Char
We can also supply intumescent from:
* Leigh’s M90
* Nullifire System E
Interact can advise which of these is the most suitable base material
for your particular application (from which Interact will cast the final
product to the right specification).
Fire Protection Period
 |
| Click thumbnail to view table A2 |
Minimum periods of fire protection for different building types and height/depth specifications are detailed in Approved Document B of the UK Building Regulations 2000.
A crucial guide within this section is Table A2.
Diameter and Quantity
Dimensions for columns should always be measured in linear metres.
The minimum casing thickness currently is 10 mm. Allowing for a further 2 mm for the adhesive, this makes for a total 12 mm layer of epoxy intumescent on to the column (ideal for most columns requiring up to 2 hours fire protection).
If fire protection greater than 2 hours is needed, the casting can be made thicker to suit—up to 32 mm (or more, if required). The thickness is dependent on the Hp/A value of the hollow section in question, and the required fire protection period.
Please contact Interact Head Office to ascertain the particular thickness you might require. Given the relevant specifications of your brief, the necessary calculations can be made.
Top Seal Finishes
Although it does not rely on any finishing coat to protect against water or chemical attack, a wide range of surface finishes and colours are also available to further enhance the overall appearance. Special anti-graffiti protection can also be applied.
For the ideal coating system, Interact’s own recommendation is either a siloxane or polyurethane (both have much longer periods before first maintenance than standard top seals). However, any top seal specification must be compatible with the base material.
Siloxane (20 years to first maintenance—and tested to Norsok standards for 13 years)
Alternative high-gloss finishes:
* Carboline Carboxane 2000
* International Interfine 878
* Ameron PSX700
Polyurethane (8 – 10 years to first maintenance)
Alternative finishes:
* Carboline 133 HB silk (or 10% gloss)
* International Interthane 870 silk (or matted down)
* Ameron TBA
NBS Architects Guidance Notes
Specification clauses can be found on Update 45 of the National Building Specification and can be specified in NBS Section M61, clauses 110, 115 and 120, with the details in the NBS Plus manufacturers guidance window.
Here is an example that demonstrates how Interact’s product might be integrated into an instruction—and how the company can help with detailed specifications and quality control checks if required:
| M61 INTUMESCENT COATINGS FOR FIRE PROTECTION OF STEELWORK |
| To be read with Preliminaries/General conditions |
PROTECTIVE COATING SYSTEMS
| 110 ON SITE COATING TO PRIMED STEEL INTERNALLY | |
Use/location: |
primer to new steel – Internal/external. |
Preparation: |
G10 |
Primer: |
Type: 2 pack epoxy zinc phosphate primer. |
Intumescent casting:
|
Manufacturer: Interact Fire Solutions Limited;
01694 751394. |
Top sealer coat: |
Manufacturer: International Paint. |
| Bolt head/nut protection: |
Seek advise from Interact Fire Solutions Limited. |
GENERAL REQUIREMENTS
| 205 VALIDATION OF MATERIALS: | |
Project specific evaluation of intumescent
casting materials: |
Standard: To BS 8202-2, clause 4. |
| 210 WORKING PROCEDURES: | |
Standard: |
To BS 8202-2. |
Give notice: |
Before commencing surface preparation and casting installation. |
|
Quality control: |
Record project specific procedures for surface preparation and coating application. |
| 215 WORKING CONDITIONS | |
General: |
Maintain suitable temperature, humidity and air quality during casting Installation and drying. |
Surfaces: |
Clean and dry at time of installation. |
| 220 APPLICATOR’S PERSONNEL | |
Operatives: |
Manufacturers approved installers
only. |
| 260 CONTROL SAMPLES: | |
General: |
Carry out sample areas of finished work as follows: Present benchmark, uninstalled sample. |
Approval of appearance: |
Obtain before commencement of general casting installation. |
| 270 INSPECTION: | |
Permit intumescent casting manufacturer to: |
Inspect work in progress. |
PREPARATION OF SURFACES
| 330 EXISTING STEEL - MANUAL CLEANING | |
Preparation: |
Remove oil and grease. |
Finish: |
To BS EN ISO 8501-1, preparation grade St2. Leave a clean but unpolished dry surface. |
Primer: |
Apply as soon as possible after cleaning and before gingering or blackening appears. |
APPLICATION OF COATINGS
| 410 INTUMESCENT DRY FILM THICKNESS (DFT) | |
Required dft: |
Determine for every steel member
to give specified period of fire resistance. Use intumescent coating
manufacturer’s current published loading tables. |
Special sections and partial fire exposure conditions: Obtain required dft in writing from manufacturer. |
|
Schedule and drawings: |
Submit at least two weeks before starting work. |
Schedule content: Member sizes, weights/ thicknesses, loading conditions, etc. showing, for each variant, the exposed perimeter/ sectional area (Hp/A) ratio and required dft. |
|
Drawing content: Steelwork drawings marked in colour to show required dft for each member. |
|
| 420 MEASUREMENT OF INTUMESCENT DFT | |
Intumescent dft: |
Check the certificate of conformity supplied by the casting manufacturer complies with the required fire protection period. |
| 460B HIGH DECORATIVE FINISH | |
| Definition: |
High standard of evenness, smoothness and gloss when viewed from a distance of 2 m or more. |
| 490 TOP SEALER COAT – Roller applied | |
Application: |
To achieve dft recommended by manufacturer and to give an even, solid, opaque appearance, free from runs, sags and other visual defects. |
| 530 RECORDS OF COATED STEEL | |
On completion of intumescent coating work submit: |
Accurate surface preparation and coating application records. |
Fire resistance certificates |
|
Intumescent coating manufacturer’s recommendations for maintenance and overcoating. |
|