External Wall Insulation Systems (EWIS) is a thermally insulated, protective, decorative exterior cladding system which involves a number of layers. The picture below shows a typical make up;
1. The substrate - this can be any type and some may need some preparation
work prior to commencing
2-3. Insulation - this is mechanically and or adhesively fixed to the walls using
either a polystyrene or mineral fibre board
4-6. Basecoat - a reinforced render which has an alkaline mesh embedded into the
base coat the system its overall strength and to prevent cracking
7-8. Finish - a decorative finish is applied. There are a number of finishes available
as detailed below
The thickness of the insulation depends on your requirements and also current building regulations, exposure and durability and whether the building might be subjected to other influences for example vandalism. Other materials used within the make up of the property also need to be taken into consideration to ensure we reduce or remove the effects of poor insulating materials.
This is a system where dry aggregates are thrown onto wet render to create the finish. There are a number of colours and different sized aggregates that can be used and can a cheaper option than other finishes.
A high performance through coloured render finish which contains silicone in the pre-mixed pre-coloured bucket. The silicone gives this product a stain and water resistant covering and helps to repel pollutants, alage and staining from sticking the coating. In the unlikely event a stain does occur the rain should remove this but otherwise a minimal maintenance maybe required to remove this. This is lightweight product which is flexible and can withstand slight movements from a building without cracking. This finish is breathable and ideal to be used on insulation or cement boards and for buildings that require a breathable system. Silicone has two textures available one in a textured finish or a rolled corrugated finish and is available in almost any colour on the market as all buckets are coloured to order.
A high performance through coloured finish which contains acrylic resin (a type of plastic) and is pre-coloured. It offers a stain and water resistant covering which also helps to prevent cracking. However, this does have its limitations from the Silicone finish. Due to the plastics it is unable to allow a building to breathe and therefore can not be applied if the building or the insulation needs to be breathe. It can not be applied in cold or wet conditions as it takes longer to dry. Unlike the silicone finish it will require maintenance as it is not as resistant to pollutants and algae in the same way as the Silicone finish. This is also available in two finishes, textured or rolled/corrugated and is available in a wide choice of colours.
Where a client wants their house to be rendered but would like a more traditional finish, brick slips can be applied as a finish coat. These are either extruded from bricks or are synthetically made. There are a wide choice of colours and textures on the market from most manufacturers, however we do work with some manufacturers who now offer a brick matching service creating authentic looking bricks. These are stuck on and then pointed afterwards.
Brick Effect Render
A slightly cheaper option for a brick finish is to use brick effect render. In essence the mortar coat is applied first to the surface and then the brick coat is applied on top, before this brick coat dries it is scored to create the bricks and to exposure the mortar coat underneath. There are a number of colours available but are monotone in their appearance compared to brick slips. This is a lightweight system allowing it to be applied on top of cement boards and insulation.
Stone Effect Render
These are popular when wanting to create or re-create a stone feature or even a full house to look like stone. As its lightweight it can be applied onto insulation and has the same properties as the brick effect render.
We work with a number of manufacturers including, Baumit, PPG, Permarock, Wetherby, Sto, Alsecco