Monthly Archives: June 2017

Silicone render systems

If you are looking to buy silicone render systems, then EWI Store is the place for you! Silicone render systems are a great way to protect the exterior façade of your home. The silicone render system helps prevent penetrating damp, as well as helping to improve the external appearance of your home.

Silicone render systems are often described as crack-free render systems, due to their flexibility. The presence of fibreglass mesh within the basecoat layer allows the silicone render system to move with the building. Also, the silicone render topcoat itself is extremely flexible. Both of these features ensure that once a silicone render system is installed on your property, it will be maintenance-free for years to come!

Our EWI Pro silicone render systems have an unrivalled track record across Europe due to their ease of install, the quality of the products involved and the fact thousands of colours are available -all delivered to site the very next day!

What makes up a silicone render system?

A silicone render system is made up of several core components, although various features like windows and roofs will potentially require some additional items to be incorporated into the system.

The silicone render system is thin coat – this means that unlike monocouche or scratch renders, the silicone system is very thin. The benefit of this is that it makes it extremely flexible; hence it is often referred to as a crack-free render system.

The first core component of the silicone render system is the basecoat layer. This is sometimes referred to as a reinforcement layer and basically consists of a 6mm layer of cement based adhesive with a layer of fibreglass mesh embedded within.

Installing the basecoat layer within silicone render systems

To install the basecoat layer of the silicone render system, the adhesive is first mixed with the correct quantity of water (most of our adhesives require 6 litres of water). This basecoat adhesive is applied using a 10mm notched trowel held at a 45 degree to the wall. It is important to ensure the basecoat layer is not too thick, otherwise it will lose some of its flexibility. However it needs to be sufficiently thick to provide some impact resistance – as mentioned, 6mm is the ideal thickness of the basecoat layer in the silicone render system.

The next stage of installing this type of render system is to embed the fibreglass mesh – this can be done in one of two ways. The first is to apply the full 6mm layer of adhesive to the wall then push the mesh into the adhesive by drawing the notched trowel up over the wet basecoat; this will pull it through the mesh. The key is not being able to see any mesh once it is embedded, as otherwise it will poke through the silicone render system.

Some installers prefer to add the basecoat adhesive to the wall in two goes. The first time, they add 3mm of render to the wall, then press the mesh gently into this. The prior to the adhesive completely drying they add the second 3mm layer of adhesive – this creates the desired 6mm layer of adhesive and ensures the fibreglass mesh is embedded right in the middle of the adhesive. Remember this is key to the Silicone render system as it ensures the system is flexible once it has been installed.

The key to all thin coat Silicone render systems is preparation. There is no point trying to apply the final top coat render if the basecoat layer is not level and you can see mesh coming through the adhesive in areas. The reason for this is that the final top coat layer is only 1.5mm (or 1mm, 2mm or 3mm depending on the size of granulate used) thick – it is very unforgiving.

Prior to applying the final top coat of the silicone render system, the basecoat needs to be primed. This primer does two things – firstly it helps limit the absorptivity of the basecoat, ensuring water is not sucked from the render at too fast a rate. Secondly it helps increase the bond between the basecoat and the render itself.

The render is applied with a standard trowel to the trowel and the excess is removed, leaving an extremely thin layer of render on the wall. Once the render has been on the wall for 15 minutes or so, a plastic float is used to give the textured finish.

Features of the EWI Pro silicone render system

  • Pre-mixed render in 25kg tubs – ready to use straight out of the bucket!
  • Our silicone render systems are available in thousands of different colours, all available to be delivered to site the very next day!
  • Our systems are specifically designed not to crack!
  • Long lasting and maintenance free.
  • The renders are UV stable, so even the most vibrant colours don’t fade over time.
  • The silicone render systems are hydrophobic – meaning they are self cleaning.
  • Our render systems are easy to install and hundreds of installers up and down the country are benefiting from this!
  • Silicone render is breathable, meaning water vapour can cross the surface ensuring the building can breath – reducing the risk of condensation.

Fixing cracked render

One of the biggest issues with old sand and cement renders is that over time they crack. The cracks may start small but before long they can really ruin the look of your home – and they can also lead to water ingress.

We get a lot of people asking us what the best solution is to fix cracked render. Well, you have a few choices, depending on the severity and size of the crack as well as how long it has been there:

1. Fixing completely blown render across the entire property

If the render is falling off the walls everywhere you have two options:

Start again

The best solution for fixing cracked render is to start again! It’s probably not what you want to read, but putting any other materials on top of cracked render is akin to adding a plaster – it is only really a temporary fix. Therefore we would always recommend removing the existing render back to the brick work, but we appreciate many people won’t do this due to the time and cost involved.

Fix render by adding a thin layer of EPS insulation

The next best solution is adding a thin layer of insulation (20mm or 30mm) to the wall – this needs to be attached to the wall with adhesive and anchored to the wall using mechanical fixings. Prior to adding the insulation board, do try to remove any very loose render and make good the surface with levelling mortar (EWI-260).

Once the insulation boards are in place, then you carry on the rest of the system as normal, adding a 6mm basecoat layer (with mesh) to the top of the insulation boards and finishing off with a render finish.

2. Fixing cracked render on one panel of wall

If there is just one area of the wall that is cracked, then we recommend applying basecoat and render to just that panel (i.e. a square house would have 4 panels, front back and 2 sides). Hopefully the panel in which the crack has occurred isn’t the whole side of the house, and there is a natural break, for example a downpipe.

By basecoating and re-rendering the entire panel, it should ensure the cracked render does not crack again in future. The flexibility of the base coat, combined with the flexibility of the render top coat, should provide a crack-free solution.

3. Fixing a very small crack or area of impact damage

There are some cases where a very small crack has occurred that needs fixing; for example maybe a bin has blown against the wall, or a car has ‘gently’ reversed into it. In this situation you have a couple of options. Firstly, you can remove a square of render around the affected area and basecoat and render this area. This involves taking an angle grinder and trying to remove a clean square around the impacted area.

Unfortunately, there will always be an issue of scarring where the new render meets the old render because both render layers can be as thin as 1mm in thickness – there is simply no way they can be blended together without scarring. The square (marked out using rendering tape) ensures that despite scarring being visible it is still neat.

The other solution for sorting a small crack in the render is to basecoat the whole panel and re-render the property – again a bit more work but you won’t be able to see where the original crack in the render was, therefore it gives a nice finish than marking out the square (as described above).

We often get people ordering additional buckets of render to make repairs on cracked/damaged render and they simply ‘touch up’ the affected area, but 99% of the time this will result in unsightly visible scarring. We would always recommend following one of the methods described above.

At EWI Store, we are very happy to provide help with cracked render – we recommend sending pictures to us at info@ewistore.co.uk and we can provide expert opinion on the best solution to getting the issue fixed!

Verge trim v3b

Waterproofing EWI systems

If you have ever installed external wall insulation, you will know the key is making it waterproof. We are not talking about water going through the render itself – to be honest, all renders should prevent penetrating damp – instead we are taking about water finding a pathway behind the insulation, either at the top of the system or around windows and other openings.

There are lots of proposed mechanisms for sealing EWI systems, but in this blog we are going to look at the best options, particularly focusing on the top of the insulation system where the EWI meets the roof.

Extending roof lines to protect EWI systems

In an ideal world, the soffit of the roof will extend out far enough to mean the insulation can be completely covered and protected from water ingress, but adding 100mm+ of solid wall insulation often means this isn’t the case.

The best solution is therefore to extend the roofline – but this is also the costliest, both in terms of labour costs and materials. It does however ensure that water going behind the system will never happen, with the extended roofline coming over the new solid wall insulation system and directing water far from the walls.

Using verge trim to protect EWI systems

If this is not possible, you need to turn to verge trim; this is what is used in about 90% of cases. When it is done well and done with the right products, this can be as effective as extending the roofline, but the quality really does vary from installer to installer.

Our preferred solution is our Verge Trim 1 – this is the perfect solution for preventing water ingress at the top of the insulation system. It essentially has a ‘T’ at the back of the trim. This ‘T’ is slipped up behind the fascia board and then screwed into place through the bottom of the ‘T’.

There is a 15-degree drop on the verge as it extends away from the wall, and then it has a drip on the leading edge to help prevent water running back along it. Verge Trim 1 is available in two different sizes to house different thicknesses of insulation. The 140mm Verge Trim 1 is used when you are using 90mm or 100mm in your solid wall insulation install. The 110mm Verge Trim 1 is used for 50mm or 70mm.

The beauty of this verge trim is the fact it goes up behind the fascia board, so there is no change of water ingress when this is used, offering a completely watertight seal.

Verge Trim 3 is very similar to Verge Trim 1, although it is fixed in place by screwing through the fascia board. If you are replacing the verge trim at the same time, you can remove the fascia board completely before installing verge trim 3, and screwing it securely in place at 300mm centres. It is then possible to replace the new fascia board in place and you won’t need to screw through the fascia board at all.

Again, like Verge Trim 1, there is a 15 degree drop on the verge trim itself, helping to ensure any water falling on top of the trim is directed away from the property. It is also available in 110mm and 140mm varieties, depending on the thickness of the insulation used.

Verge Trim 2 is very popular although perhaps the most basic of our verge trim covers. This is simply attached to the wall and then where the verge travels away from the wall, it must be siliconed – ideally with CT1 or another hard-wearing silicone sealant. A combination of the verge trim and the silicone sealant will help prevent water ingress. Like the other verge trims, there is a 15-degree angle on the verge itself (which covers the insulation), and it is available in either 110mm or 140mm varieties.

tools

New to EWI – What tools do you need?

Applying external wall insulation to the wall can be a bit daunting to those new to it. There are several different layers to the system. Therefore, in this blog we are going to describe the basic tools needed to get the job done, but we are also going to look at the some of the additional tools you might want on site if you are looking for that professional finish!

Paddle mixer (plasters mix)

Our external wall insulation and render systems all involve adhesive. For the insulation systems, the adhesive is used to stick the insulation boards to the wall as well as the basecoat layer – in render only systems, adhesive is only required as part of the basecoat layer.

The first thing you are going to need then is a paddle mix. These come in a huge number of sizes and types. It is not something we would scrimp on because as an EWI installer, much like a plaster, you are going to be using this on a daily basis – we would recommend something like the Mikata UT1400.

Likewise, we have a few different mixing paddles – although here we certainly have a new favourite. The OX Pro Mix M8 Rubber Blade Mixing Paddle is relatively new to market, but it is designed to reduce mixing time, prevent damage to buckets and provide much longer tool life – the difference is basically it is made from tough rubber rather than steel – you need to try it for yourself!

TOL-211 Mixing Drill Piece

Notched trowel

Next on our list is our Notched trowels. Typically, there are 2 that are used – the 10mm notched trowel and also the 4mm trowel. The 10mm trowel is used to apply adhesive to the back of the board (if you are covering the whole board) as well as for the basecoat layer. The notched trowel allows you to get an even depth of adhesive on the surface – by holding the angle of the notched trowel at 45 degrees, a dragging the trowel across the surface, a 6mm layer of adhesive will be deposited on the wall or insulation board.

The 4mm notched trowel is used specifically for brick slips – the adhesive in this case is applied as a much thinner layer than the basecoat or when the adhesive is applied to the back of the insulation boards.

TOL-103 Square Notched Trowel

Bucket trowel

The bucket trowel is an essential tool for any plastering, rendering or EWI job. This is used for loading adhesive on to the notched trowel or for putting adhesive on a surface. We do offer a premium bucket trowel with a rubber handle that some of our installers prefer!

TOL-106 Bucket Trowel

Drill bits

There are only 2 drill bits you need when carrying out EWI, one for the rawlplugs for the starter track and the other for the mechanical fixings that go through the insulation boards into the substrate.

The rawlplugs / screws that hold the starter track to the wall require a 6mm drill bit.

The mechanical fixings require either an 8mm drill bit for the metal fixings or a 10mm drill bit for the plastic fixings.

drill

EPS rasp

The EPS rasp is only used for external wall insulation systems – it basically works like a large cheese grater, allowing you to shape the surface of the EPS insulation, to provide a flat surface on which to apply the basecoat part of the EWI system. Also you will sometimes find the surface of the EPS insulation is quite oily, therefore the rasp can be used to remove this top oily layer which may aid the adhesion of the basecoat adhesive.

TOL-109 Steel EPS Rasp

Bucket trowel + steel float

Prior to using the plastic render float to achieve the finish on the top coat render, you need to get the render on the wall. We suggest using a combination of a bucket trowel and a steel float to get the render where it needs to be! We won’t go into any further detail here as most builders will have a pretty good understanding of how these work – the key though is to apply the render as thinly as possible.

TOL-112 Plastic Render Float

Plastic render float

Once the render has been applied to the wall you need to use a plastic render float to get the textured finish. This is done by putting the plastic render float flat on the wall and moving it in quick circular motions. This pulls the aggregate to the surface of the render and is the required finish!

PVC float trowel side

Sand and cement render versus thin coat render systems

Up until about 10 years ago, if you decided to render your property, the builder would most likely have used a sand and cement render. Sand and cement render is made by mixing 4 parts sand with 1 part cement and is applied to a depth of about 10mm – 15mm. The problem with it is that it has no give. Over the course of a year, your home will expand and contract as the weather changes – in cold weather the house will actually shrink and the opposite is true during the summer months.

Sand and Cement renders Crack

The problem with the older sand and cement renders is that as the building changes in size, the sand and cement render won’t move with it. The result is that the old sand and cement render will begin cracking. At first you will begin to see hairline cracks but as time goes on and water begins to get behind the render, it may begin coming off the walls.

One of the ways of limiting the cracking that occurs when sand and cement render is used is the addition of lime to render. When you mix lime in with sand and cement, the finished render coat will have greater flexibility. It is not completely flexible so will still be liable to cracking, but it should be a significant improvement on sand and cement alone. The presence of lime in the render also improves its workability, making it easier to spread.

K-Rend also cracks eventually!

To be honest, any thick render system is liable to cracking; it is not just sand and cement render. K-rend and other scratch renders are also more likely to crack than more modern thin-coat renders. It’s not that they are bad products – in fact K-rend is probably the UK’s best selling render – but the unavoidable fact is that any render applied that thickly is more likely to crack.

Thin coat renders are virtually crack proof!

As time has gone on, people have been seeking ‘crack proof’ render finishes. Our thin coat render is just that. It has a flexible fibreglass mesh embedded within the basecoat adhesive and this gives it flexibility. The top coat render is also very flexible. If you put the render as a test on a piece of EPS, you can then flex the EPS and the render will still not crack.

When you consider the overall thickness of the EWI Pro render system then it is much much thinner than K-rend and other scratch coat renders. The basecoat adhesive is just 6mm thick, and the render topcoat can be as thin as 1mm, this takes the whole system up to a thickness of just 7mm. The flexibility of the components and the fact they are applied very thinly means the system will genuinely move with the building so the render system will stretch during the warmer summer months and when it gets cold in the winter, the render system will shrink.

Crack proof and maintenance free render!

The beauty of this system is that once installed on your property it will genuinely last, with no cracking and no maintenance required. You can install the system your home and then rest assured knowing the system will last decades!

We do recommend you get qualified installers to install the system though. The reason for this is that since the system is so thin, it is fairly unforgiving to install. Qualified installers will be able to get a lovely finish – one that you will be able to admire for years to come!

Wet dash vs. 3mm silicone render

What is wet dash?

Often used in the more exposed locations in the north of the UK, wet dash is a mix of several components: three parts sand, one part cement and one part small – usually a sharp granite – gravel. This is all mixed manually and applied to the wall in a thick layer. Once dry, the layer is painted, to create a coloured finish. Although very strong, dash render is brittle and not particularly resistant to cracking.

What is silicone render?

Silicone render is  often referred to as a thin-coat render. Thin coat renders have two distinct layers: a base coat, usually reinforced with a fibreglass mesh, and a thin top coat which has the colour pre-mixed into it. The whole system is usually only a few millimetres thick, but the thinness and reinforcement make for a very strong, crack resistant, and flexible render.

Why use large-grained silicone render instead of wet dash?

  • Silicone render is durable. One of the main reasons for dashing is its robust and durable finish. Silicone render is a highly flexible and durable product that is very resistant to cracking and weathering.
  • You won’t notice the difference in appearance. Silicone render has that same rugged finish that is distinctive with wet dash. The good news is that there is a whole range of silicone render. You can opt for a rough finish to emulate the dash, or go for an ultra smooth 1mm finish which has just a slight texture to it. With dash you just have that one option of a rough finish.
  • You can colour your finish. Silicone render comes pre-coloured in a huge array of different colours, so you can pick any sort of colour finish you want! There’s no need to paint the dash after application, silicone render is pre-coloured and the same colour all the way through the top coat, so even if you scratch the surface it won’t show like dash.
  • Silicone render is easier to mix. Wet dash will require premixing several different ingredients to get the right recipe for the render. Get any of these ingredients in the wrong ratio and you may have issues with the finish. Silicone render comes pre-mixed so you don’t have to do any preparatory work, just apply straight onto the basecoat.
  • Silcone render is easier to apply. Silicone render is a one application, hand-applied product. You can render a whole house in just a few hours onto a pre-prepared surface.

Silicone as an alternative to roughcast and dry dash

We think silicone also makes for a great alternative to other traditional renders. Thin coat render like silicone is much more flexible than these old-fashioned renders. This makes it more versatile, as well as being more resilient. Once you start using thin-coat silicone render, you really won’t want to go back.

For the customer, it is always annoying to have those random stones dropping off the wall 5 years down the line. This is almost unavoidable with dry dash, but with silicone render the pebbles are deeply embedded in the mix, and there is no danger of any loose stones.

Silicone render is breathable too. Where your old style mix of sand and cement blocks up the wall, this render allows moisture to move through the wall. Another great reason to use silicone!

Will silicone last as long as dash?

EWI Pro silicone render has an expected lifespan of more than 30 years. This is more than any guarantee you will get on a dash render system. In our opinion there is no reason why a silicone render can’t last as long, if not longer, than a dash render.

Will silicone cost more than dash?

This will depend somewhat on the type of dash system you are using. Thin coat renders are usually a bit more expensive, but you will use less of them because of the thinner layer required. You might be surprised at just how cheaply you can get a thin coat system.

Uploaded To Where have there been grants for EWI?

Are there grants for EWI?

You may have had a neighbour tell you that they got a grant for their EWI, but how? In this blog we are going to take a look at some of the funding possibilities and see if you could get a contribution towards the costs of your EWI.

The Green Deal Home Improvement Fund

Many people got their EWI installed a year or two ago under the Green Deal Home Improvement Fund. Unfortunately this grant is no longer available, so you won’t be able to take advantage of it. The grant was very generous giving around two thirds of the cost of the works, but there are some other possible avenues of funding available.

What funding is available now?

Whilst the Green Deal has been shelved, there are several avenues you can try to get funding. Firstly, some local councils have pots of funding available for this kind of work, so it is always worth checking to see if you might be eligible for any scheme they are running. This might be a bit of a long shot however, so failing that your best chance is to get some ECO funding.

What is ECO funding?

ECO, or the Energy Company Obligation, is a government scheme that requires energy companies to contribute towards energy efficiency improvements. This is not limited to solid wall insulation, you can also get funding for cavity walls and loft insulation, and some other measures. How does it work?

ECO is split into a couple of funding streams. There is funding for those on limited incomes and in certain groups such as low income pensioners, those on disability benefit and a host of other benefits. You can find information on the qualifying groups here.

If you are not in one of these groups, there is another income stream which varies based on the carbon savings that EWI would make on your property. This is not income restricted and is simply based on the EPC survey carried out on the property. Whichever funding stream you go for, the amount you get will be limited. Unfortunately external wall insulation is not cheap, and the funding is not going to cover the cost of the job. The actual amount you will get varies depending on your home, but in most cases you’ll be looking at around 10% off your final bill.

This means that ECO will only pay for a fraction of the job. There are quite a few administrative hurdles to jump through on the installer’s part, and you will have to fill out quite a few forms. Many installers decide that this simply isn’t worth the effort and don’t offer ECO, instead offering better prices for those who pay privately, or offer alternative financing options.

Finance as an alternative

With interest rates low, there are some really good personal loans available that can help cover the cost of EWI projects. The rates are often very reasonable and set up fees are low. If you can’t afford the upfront payment, then this may be a possible alternative. Of course, you need to check out exactly what you will be repaying and ensure it is affordable for you. Installers will often use third party funding organisations to avoid having to become FCA accredited, so just be aware of what you are getting yourself into.

Get great value instead of a grant

With grant funding so limited, and ECO funding often less than the premium that an installer will stick on top of the job, it might be worth getting a better price privately instead of trying to find a grant. You may wish to buy the materials for the job yourself directly from us, and then get a local tradesman to do the work. This is often quite a bit cheaper than going to an installation company, but you should make sure the installer is competent and you are happy that they are going to carry out the work satisfactorily. We recommend any installer be carded with the system in question before they do the work – something we can help organise for you.

Whatever route you choose, EWI will not to be cheap. What we can guarantee is that when EWI is carried out to a good standard, your property will feel much warmer and have much lower bills for years to come.

For recommended installers, give us a call or visit our partner TheGreenAge’s local installer map.