Grafo Products Ltd.          Application Data Sheet

Any material such as -
STEEL, ALUMINIUM, CONCRETE, WET INSULATION, etc., capable of transferring external temperature onto the internal surfaces of buildings and other structures must be considered a potential source for condensation.

Here are some examples showing where and why Grafo-Therm should be applied:

BUILT UP OVER-PURLIN ROOF AND INSULATION SYSTEM.

This popular system can be made up from a variety of materials with an air space for natural ventilation and as such it has a natural capacity to produce condensation to an extent whereby the cavities interior surfaces may be subjected to moisture for very long periods over winter, more so than exterior surfaces of the weathering roof sheet, and of course these surfaces will not normally have the same protection against corrosion.
Condensation control should be designed into this type of system and this can effectively be achieved by fixing roof sheets which have been pre-treated with Grafo-Therm, and by ensuring that the space between the roof sheets and the insulation is of sufficient depth to enable some movement of air under all surfaces of the roof sheets.
Eves and Apex ventilation will be necessary to enable good airflow up to the pitch.
Metal lining sheets do not prevent condensation forming in the cavity.
Correctly designed, this type of system can provide excellent pay back value with long life.

SINGLE SKIN ROOF WITH A HORIZONTAL INSULATED CEILING

This system is mainly used in buildings which require a high class interior finish such as offices, computer rooms, etc., with a heat loss control 'U' value of 0.35W/M2 °C or better.
Normally the use of these buildings promotes higher than average levels of humidity.
This type of insulated system generally shows its condensation problems clearly through the damage it causes to ceiling tiles, the costs involved in renewing these materials makes this one of the most serious condensation problems.
This system usually provides a large air space above the insulation which is not often designed to provide for efficient means of ventilation.
If allowed to, natural ventilation from the eaves will track across the insulation and out at the opposite eaves leaving the areas of condensation on the underside of the roof sheets dormant. A simple barrier through the building below the apex would divert the airflow up the roof pitch.
Metal or aluminium roof sheets should never be used in this system without condensation control and in this application Grafo-Therm is superb whether pre-sprayed or as a remedial treatment.
For full Technical Specifications of Grafo-Therm see pages 1-6 below Page 1  Page 2  This is Page 3  Page 4  Page 5  Page 6
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Manufactured by Grafo Products Limited

Sales Office - Rosemount, Broadway, Upper Holton, Halesworth, Suffolk, IP19 8QN.
Tel: 01986 873127 Fax:01986 872850 Email:grafo@grafoproducts.fsnet.co.uk