Tag Archives: external wall insulation

External Wall Insulation and Verge Trims

Verge Trims are suitable for most situations requiring the capping of external wall insulation systems and rendering systems.

A verge trim is a thin strip of plastic or metal that sits at the top of the wall where the insulation meets the roofline. Our verge trims are made from 1mm powder coated aluminium. This verge trim is designed to be tucked up behind the fascia board and comes in various widths to house different thicknesses of insulation. The purpose of verge trims is to create a water-tight seal that prevents any moisture penetration behind the system.

As we know, water ingress can be extremely detrimental to an EWI system. Water has a direct effect on the insulating properties of the EWI because water reduces the ability of the insulation to slow heat transfer. Water ingress can also be really dangerous for the structural integrity of the external wall insulation system. Continuous water penetration will eventually wear away the adhesive materials, which can eventually cause the insulation boards to become insecure and even fall off the wall and cause injury. This is why technical design using verge trims is so important, and why EWI installations need to be done properly by fully trained installers – such as ours.

When it comes to an EWI installation, properties will vary depending upon the type of roofs they have. Some roofs have a wide enough soffit to allow the insulation to sit underneath. In this case, good quality beading will be sufficient to create a seal with the soffit board, and water ingress should never be a problem because the water will simply run off the side of the roof. However, not all roofs have a wide enough soffit to accommodate the insulation, and in these cases, a verge trim is usually required to ensure the water does not run down the back of the EWI boards.

Extending the Roofline with Verge Trims for EWI

Extending the roofline with verge trims is particularly useful on gable walls where the tiles stop abruptly at the edge of the gable wall. In this situation, timber battens can be installed, and a new row of tiles can be added to create an extended roofline on the property. The insulation will then slot underneath this perfectly, creating an ideal waterproof solution.

However, there is a downside to this method. The cost of this procedure is can be somewhat expensive, especially when considering that external wall insulation isn’t exactly a cheap procedure. so here at EWI Store we have taken this into account and we have designed a more affordable option which is equally as effective.

Verge Trim – Creating a Waterproof Seal for EWI

The solution is simple: where there is a fascia board, it is possible to tuck verge trim behind it, or up under the roofline. Here at EWI Store, we offer a range of verge trims to suit your needs. Our Verge trims come in two standard sizes 110mm and 140mm. We offer three types of Verge trims.

Verge trim type 1: This verge trim can be tucked up behind the facia board and then attached to the wall using screws at 300mm centres eliminating the need for silicone as there are no sites for water ingress

Verge trim type 2: This verge trim is the standard verge trim which is placed under the roofline. The join is then sealed with silicone sealant to help prevent water ingress. This is usually sufficient where there is guttering to help the water drain away, but in more exposed places the silicon can fail quickly and allow moisture behind the system.

Verge trim type 3: This verge trim is to be used in place of fascia board this provides a water tight system which prevents water ingress behind the EWI System.

We offer a selective range of different styles and colours of verge trims to create your dream property. Give us a call on 020 3397 4067 to get a quote for our EWI system or if you need an EWI installer.

external wall insulation EWIPRO

How can I insulate my external walls?

Why should I consider external wall insulation?

Perhaps you have installed cavity wall insulation but are looking for a bigger impact, or maybe you live in a solid walled property. We recommend external wall insulation for a number of reasons;

  • Save energy and therefore save money on bills
  • Improves the external appearance of home
  • Improves the acoustics within your home – sound proofing
  • Takes up no internal floor space
  • Keeps home warmer in the winter and cooler in the summer (many people report that their houses stay so warm that they hardly need to turn the heating on)
  • Prevents damp and condensation
  • Prolongs the life of your building – protects against extremes of weather
  • Can increase the value of your property in terms of external appearance and Energy Performance Certificate Rating
  • Low maintenance and long lasting

A quick run through of the main stages of installation:

First, the wall is prepared to make sure the insulation system will stick. It should be possible to install our insulation system on top of existing render or pebbledash, but at this point a substrate check will need to be done. Next, the surface is primed and this needs to set for 24 hours. A starter track is attached to the wall above the damp proof course to support the insulation boards. They are then attached with adhesive and double-fixed with mechanical fixings. Fibreglass mesh is used to reinforce the system and then the wall is rendered and a topcoat applied. Each part of the system is designed to minimise cold bridging and maximise efficiency.

Can I choose the materials?

All the steps work together to create an effective, attractive and long-lasting system. It’s a customisable system – the householder can choose between three insulation materials: mineral wool, expanded polystyrene (EPS) or extruded polystyrene (XPS) boards. Mineral wool is durable, breathable and highly fire retardant. Polystyrene insulation is cheap and a fantastic insulator, so a thinner layer can be added to achieve the same results as a larger amount of mineral wool.

There is also a choice of render, tailored to different environments, as well as options for the final colour and texture of the walls.

How much does external wall insulation cost?

Fill in our calculator to find out approximate costs of materials or give us a call and we can put you in touch with one of our approved installers who will be able to carry out the work for you to the highest standard. All our installers are given full training and we offer a free aftercare service for customers.

Check out our video with TheGreenAge all about installing external wall insulation!