Best Practice For Exterior Wall Coating
- Brian Tones
- Oct 21
- 2 min read
Exterior Wall Coating Costa del Sol do's and don't from the people who understand building structures.
Paint consists of four main components: pigments for colour, resins to act as a binder and help it adhere to a surface, solvents to control consistency, and additives to enhance specific properties, usually profile.
What is the secret of achieving the perfect coating.
Preparation of the surface its to be applied.
High quality additives.
High level content of quality pigmentation.
Can paint provide thermal benefits?
It may seem a strange claim when a wall is 30cm plus deep, that a 1mm paint film will provide warmer walls, and you would be right in questioning such a statement.
Thermal conductivity is increased by moisture levels, so a damp wall looses heat by conductivity, transmitting the outdoor temperature indoors. Paint therefore does not directly thermally insulate, it stops moisture penetration which reduces wall thermal conductivity.
Built in high thermal membranes.
You may find contractors offering a coating which is incorporating a structure built into product. This may consist of small plastic beads or other small crushed thermal additive.
The claim is "thermal benefits resulting in a warmer home" (well we covered that above) our point here is about its ability to adhere long term to a wall, and here is why. A exterior paint should as near as possible maintain the same temperature as the wall it is applied too, so a thin membrane is good. If a thicker thermal element is applied this wall absorb the outdoor temperature, during warmer weather the thermal barrier acts like a poultice and draws moisture up between the paint and the wall resulting in a separation. Many contractors have fell foul on that one.
If you need thermal wall insulation. Cladding for exterior, dry lining or specialist coating spray for the interior.
Breathable Paints.
Breathable paints are not fully waterproof as they have an elastic type membrane which opens to allow water vapour to pass through. Being not a fully sealed finish algae can enter, develop and form a separation in the bond.
Not all paints are suitable for all surfaces. Some mineral paints, for example, are not suitable for application over conventional acrylic paints. Paints should always be specified subject to a site survey.
And Finally Colours.
In short at greater the reflective ability the better all round, so white is tops for sunny climates.
Exterior wall coatings Costa del Sol
Comments