Rockwool insulation

Ordering the correct amount of materials for a solid wall insulation or rendering job is not always as easy as it might seem. In order to make this easier for our customers we have developed an online tool that is incredibly simple to use and produces a PDF of all the required materials.

You can start using the EWI Store calculator by pressing the start calculating button below:

How to use the solid wall insulation calculator

Please press “Start Calculating”

Question 1 – Type of Render

– Choose the render system you are interested in; there are three options, premium, standard and eco, these relate to the top-coat/finish you want on your property.

Premium – EWI Pro Silicone Silicate Render is the most popular finish (top-coat) especially when using the EPS or mineral wool external solid wall insulation systems. It is available in 100’s of colours (extra cost), and is breathable and hydrophobic meaning it will self-clean and is water repelling. It is a sympathetic render which is highly durable and is recommended for all older buildings

Standard – EWI Pro Acrylic Render is a slightly cheaper finish especially when using the EPS External Solid Wall Insulation. Available in 100’s of colours (extra cost), this render will hold vibrant colours longer (without fading), however although tough against variable weather, it can crack over time and does need additional maintenance.

Eco – EWI Pro Mineral Render is the preferred choice for installers looking to carry out work in harsher conditions (wet / cold) since it dries very quickly and is fantastic at withstanding impacts. A silicon paint is added after application of the mineral render – and it is for this reason, we recommend this render for those who like to change colour of their property on a regular basis. For installers, although mineral render is cheaper to buy, the fact it needs to be painted once the render has been applied – the increased labour costs make mineral render and SiSi render similiar in price.

Question 2 – Amount of m2 required

Enter the amount of system required (so the coverage in m2); this is simply calculated by multiplying the height by the width of each wall you are looking to insulated. Do not subtract doors or windows as it will give you an incorrect reading since our calculator builds in wastage into the final calculation.

Question 3 – Type of insulation

Next you need to specify whether you want to use mineral wool or EPS (expanded polystyrene). EPS is cheaper and offers greater thermal efficiency (when comparing like for like thicknesses) however mineral wool is fully breathable (provided mineral or SiSi renders are used). Mineral wool is also a flame retardent.

Question 4 – Type of mechanical Fixings

Enter the type of mechanical fixings you want, we offer two main types – metal or plastic pin. If you are using EPS insulation you can also use the premium EcoDrive mechanical fixings – these are simply screwed in, so fixing is quicker. Both the metal and plastic pin mechanical fixings require hammering. All the mechancial fixings can be bought with EPS caps to help minimise thermal bridging, however the EcoDrive have these built in.

Question 5 – Thickness of insulation

Thickness of insulation is up next – obviously the thicker the EPS or mineral wool the better the insulating properties. For our EPS (Expanded Polystyrene) there are three choices – 50mm,70mm,100mm. The depth of EPS is to do with u-values, new build properties currently need to be less than 0.3 W/m2k. 100mm give gives a u-value of 0.27 (the lower the better), thus saving on heat loss and more importantly bills. 100mm is always advised except where insulation has already been added to the inside of the property or external space is in short supply.

For mineral wool we offer 2 thicknesses – 100mm and 120mm. For this type of insulation 120mm is required to achieve a u-value of 0.3W/m2k

If buying a building a property to rent out or converting commercial buildings, councils insist on 100mm.

Question 6 –  Number of Corner beads

Calculate how many linear metres of corner bead you need. These are required around window and door reveals as well as the corners of the building. They provide a straight corner edge and also provide strength.

Question 7 – Number of Stop Beads

Stop beads are similar to corner beads providing a clean finish when butting up to doors and windows, when a point of termination is required. They help to prevent cold bridging.

Question 8 – Number and type of starter track

; Measure the linear meters around the property – remember our starter track comes in 2m lengths, therefore divide the total linear metres and divide by 2 to calculate the number to put in this box. uPVC starter tracks need no spacers, no mesh and allows the wall to be uneven, due to the flexibility of the material – it also minimises cold bridging. It is for this reason that the uPVC starter track is considered the premium starter track.

Hit Next to produce a materials shopping list.

This can then be downloaded as a PDF and we can quickly process these orders if you are interested in getting the materials dispatched.