ThermaTech (or DoFF) Cleaning System

For examples please see here

The DOFF  or ThermaTech “Superheated water” system is very different in action to other ‘steam’ or ‘hot water’ systems currently available on the market and should not be confused with them. It uses ‘superheated’ water which exits the nozzle, in a fan pattern. The system uses a normal water supply, which then enters a pressure pump unit, here the pressure is increased to the required level before entering the ‘Hotbox’. The pressure can be adjusted by the operator and is independent of temperature settings. Within the heater unit, the temperature can be increased up to 150°C, before it passes through a heat resistant nozzle. This nozzle directs the super-heated water onto the surface to be cleaned in a scraper like fan. It is then a case of moving ‘the scraper’ over whatever is being cleaned in an even and methodical manner.

This system can be used to remove organic matter (mosses / lichens / algaes) from most surface especially stonework and brickwork. *Note this system will not remove mineral deposits from a substrate unless they are loose – so mineral paints / sulphation & rust (both ferrous and copper) will need further treatments after they have been initially cleaned with a superheated water system. The heat of the water also helps to kill the spores of organic matter thus increasing the length of time needed between cleaning. This does not however stop all regrowth. To do this a biocide of some type will be required. Advice can be given on this after contacting us with your requirements. This system is also used to remove paints from stonework and brickwork – in some cases a paint softener will also need to be applied to the surface to assist in removal.This system is very kind to the substrate that is being cleaned and is therefore generally liked and approved by listed building officers throughout the country. One of the great attributes of the ThermaTech / Doff system is that it is able to clean at very low pressures. – That being said if an area of wall (stone/brick) is loose or flaking or an area of pointing is failing then this system will still help you find it and therefore remove it so that it can be consolidated or sympathetically repaired.

To see the difference between a normal pressure washer and the DoFF System please look at the photo below. The stone being cleaned was a portland stone used on a wall as a coping stone. The area on the right was cleaned with the Superheated water whereas the area on the left was cleaned using a high pressure pressure washer. The area in the middle was the control area – i.e. left dirty!

DoFF vs Pressure Washer

Before you start to remove any wall coverings I have one word of caution –

You can’t make a silk purse out of a sows ear !

Before you remove any coating / paint etc from anything ask yourself why it was put on in the first place? What is it covering up?

Other tasks that the superheated water cleaning system can be used for :

Removing Limewash from Random Rubble Stone walls
Remove paint from engineering bricks
Working at low Pressure remove sulphation from Bath Stone Door/Window  surrounds
Clean up old Beams
Distress New Woodwork to make look older
Graffiti Removal
Remove dirt and loose mortar from random rubble walls
Clean up and remove paint / stain from staircases and wooden banisters
Remove paint from wooden tongue and groove
Remove years of grime from wooden stable stalls

Applying a Poultice

Poultices can either be made up or bought in – they are used to apply a chemical onto a surface for a length of time to help in either ‘drawing out’ substances from stonework (e.g. to remove the green copper staining) or to soften up a substance that is sitting on top of the substrate (e.g. to remove sulphation from under window cills or weather protected walls). Using a poultice will depend upon what is being cleaned and where it is.

For further information please either call us on +44 (1666) 841338 or email us via the contact us page.