Timber framed buildings are becoming more popular due to the speed of construction and flexibility in terms of finish options.

EWI and thin coat render systems are particularly suitable for this popular construction method. However, while popular and suitable for the modern market design considerations are different. Higher levels of movement, differences in thermal performance and fire risk implications are all to be considered.

There are a wide range of finishes available including through colour silicone & acrylic, scratch render through colour finish, brick effect, brick slip & aggregate dash - all in a wide range of colours.

EWI systems that are available from our suppliers come with a British Board of Aggrement certificate and a 10 year warranty.

Key Features & Benefits

All of our Suppliers provide certified systems for use on to timber frame that offer a comparable warranty.

The section through image shown to the left is by Permarock. While offering EPS & Phenolic Insulation options Permarock have a long-standing relationship with Rockwool Mineral Wool Insulation. Such systems provide a non-combustible cladding solution for both domestic & commercial buildings.

As with all industries, manufacturers are striving for improvements to their systems. The fixing methods below from STO showcase this.

ROCKWOOL Stone wool is non-combustible and will slow the spread of fire, increasing the safety of occupants and also helping to protect both the structure and contents of the building.


Timber frames offer a more sustainable method of construction. This method of construction is also popular in the development of Passivhaus projects.

The picture below shows the cement particle board phase at a recently completed Passivhaus project in Wales.

EWI Rail Systems for Timber Frame

The CAD drawing above is of the system shown in the image below it.

Cavity Rail EWI systems meet the requirements of NHBC & TRADA

Timber framed buildings with an external wall insulation system require specific design to effectively manage condensation, higher levels of movement and greater working tolerances. Cavity rail EWI systems provide a clear drained cavity or drained and vented cavity between the insulation board and the sheathing board of the structure.

There are other Vented Cavity systems available on the market. The picture above shows cavity rails installed as part of a Wetherby EWI Cavity rail project in Worcester.


8th January 2020

Constructionline GOLD member

Specialist Render & EWI Contractors GPD Contracts ltd confirm Constructionline Gold level membership For Supply and installation of : Specialist […]
10th April 2019

1st generation EWI Replacement in Hereford.

After 3 years in Hereford, External Wall Insulation replacement works by GPD Contracts are nearing completion. Works have consisted of […]
8th January 2019

Non-combustible EWI cladding in Cheltenham

GPD Contracts were invited to replace an EWI system in Cheltenham. The new External Wall Insulation satisfies both the Vapour permeability & Non combustible required.
2nd June 2018

EWI supplied to a Bungalow renovation near Pershore…

We have been pleased to again work with David Smallcombe builders Their project involved the complete refurbishment and development of […]
6th April 2018

Rendering – Health & Safety

GPD Contracts ltd recognise and embrace the importance of Good health & safety practice. A safe environment for our team […]
19th January 2018

EWI (External Wall Insulation) removal & replacement in Hereford

Replacement of 1st generation EWI to a local authority housing complex in Hereford. The original installation was completed 10 years […]