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Common Mistakes during EWI Installations

Common Mistakes during EWI Installations

Life doesn’t always go to plan – sometimes common mistakes during EWI installations are made and things can go wrong. It’s always frustrating when something goes wrong, but rest assured there is usually a solution to the common mistakes that are made during EWI installations! We have a close relationship with all of our installers who come to us for technical advice when things don’t go as planned, which is why we know exactly how to fix the usual issues!

Our render and EWI systems are all highly specialist and need to be installed properly for full functionality. With that said, we do offer training sessions and the chance to become one of our approved installers if you attend. These sessions run every Thursday from 10am onwards and teach attendees all about our systems, how to install them and what the products are all about.

For installers who are just starting out, it takes a while to get used to the installation process, including on-site organisation, timings, materials and how best to use them. So with the intention of pre-empting any problems, here are a few common mistakes and solutions that an installer might face during an EWI or render-only installation.

On-site Planning and Organisation:

A common mistake during EWI installations is a lack of organisation and planning. Installing EWI is a process that not only involves high skill but careful planning of timings. There are many things that require an installers attention, and slip-ups can easily cause a halt to on-site works, wasting your time and money! Here are a few things to do with planning and organisation that may go wrong…

Delivery doesn’t come on time

When ordering materials, careful planning needs to go into making sure you are ordering the right quantities and that you are ordering far enough in advance to ensure that the materials arrive in time for the job to start. It’s so frustrating when workers are idle on-site because the materials haven’t arrived yet; with some companies, delivery times can be slow and on-site delivery may not even be on offer. One of our key priorities at EWI Store is making sure that we offer next day delivery. We aim to get our materials out to installers as quickly as possible, and we even have our own delivery drivers to do the job to make sure it happens!

Furthermore, if you do find that your materials are late then feel free to pop down to our premises and pick up some starter tracks so that you can at least be doing something while you wait!

Weather Conditions

When it comes to EWI and render, careful attention must be paid to the weather conditions. The materials cannot be used at low temperatures (unless you’re using our Winter Adhesive and Mineral Render!) and they cannot be used when temperatures are too high. The installation process also cannot be carried out during rain, because as we know damp can inhibit the functionality of the insulation. Always be on top of things by keeping an eye on the Met Office weather updates, this way you hopefully won’t find yourself in a situation where all of your workers are on-site and unable to do anything due to rainy conditions!

Installer-Client Communication

Part of on-site organisation involves communicating with the client to ensure that your requirements in order to carry out the work are met. If you find that the client has gone off to work and left you without access to the property for water and electricity, then you may find yourself wasting money on bottled water and even a generator. Communication with the client is key to ensuring a smooth installation process!

Drying times

Different materials at each stage of the EWI installation process have different drying times. When materials aren’t left to dry for long enough, or they’re left too long and are no longer workable, you may find that the quality of your work is impeded upon. For example, a common mistake during EWI occurs when the basecoat is left too long in the bucket and then applied directly to the substrate without re-mixing it will set much quicker and its workability will be dramatically decreased, resulting in a not-so-smooth finish. Always pay attention to the drying times on the bag, and attend one of our training sessions where all of these things are covered!

EWI Materials and Common Mistakes:  

At EWI Store, we offer free training sessions for any installers who are keen to use our materials. Those that attend are then qualified as approved installers, which means they have the knowledge and know-how that is necessary for a successful installation. Unfortunately, sometimes things can go wrong with materials on-site, whether it’s user error or other. The following are some examples of these problems.

The render is applied too thick

Our thin coat renders are designed to be applied just a few millimetres thick. Most installers who have used EWI Pro thin coat renders before will know that the thickness of the application should match the grain size. So, if you’ve chosen a 2mm grain size then you should apply it at a thickness of 2mm.

For many installers it can take a while to get used to this, and often common mistakes during EWI occur when the render is applied far too thick, purely because installers are more used to working with plaster and cementitious products with thicker application rates. In order to fix this, the quickest method is to use a plastic render float to scrape the render back to the correct thickness. Make sure you keep an eye that all the workers are applying the render correctly, as if not you will need to act fairly quickly in order to scrape it back.

Plastic fixings break

Our plastic fixings are designed to be used with our EPS (expanded polystyrene) insulation boards. One of the common mistakes during EWI is to use Plastic Fixings for unsuitable insulation materials; for example, Plastic fixings will not be suitable if you are installing Mineral Wool or Wood Fibre insulation, as these materials are too heavy for the fixings to be able to hold their weight. Not only this, but all fixings need to go through both the insulation board and the substrate in order to be totally secure. If your fixings are breaking, then it could be that you aren’t drilling them in far enough. After a while you should be able to judge this by eye, but to be really sure you’re drilling far enough through then we recommend putting a piece of tape on the drill bit to indicate where you would stop drilling.


Basecoat and mesh can drag

When installing Fibreglass Mesh and embedding it within the basecoat layer, the mesh is first placed onto the basecoat and then, starting from the bottom, a trowel is used to drag the basecoat through the mesh, embedding it in the process.

With this technique the mesh can sometimes get caught, and rather than becoming embedded it is simply dragged back up the wall with the trowel creating a bit of a mess. To resolve this, we first  recommend making sure that the basecoat isn’t too wet before you attempt to embed the mesh. If this does happen, simply remove the mesh and start again, but if you find that there’s a tear in the mesh you will have to add another layer on top to reinforce this area.

There you have it! We hope that this was informative and helpful for those just starting out with EWI. Don’t forget to attend one of our training sessions which run every Thursday if you haven’t already. We upload new content every Tuesday and Thursday all about render and EWI, with information blog posts about different products, technical advice and answering customer’s FAQ’s.


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