What is felt roofing?
Felt roofing is a popular, cost-effective flat roofing solution widely used across the UK for residential, commercial, and industrial buildings. This roofing method involves layering bitumen-coated felt sheets onto a base structure, providing a waterproof membrane that protects against the elements. Felt roofing is particularly favoured for flat or low-pitched roofs due to its versatility, affordability, and ease of installation.
The typical installation process involves laying the felt in layers, often with the use of a torch to adhere the felt to the roof surface. This creates a durable and weather-resistant surface capable of withstanding the UK’s varying climate. A top layer is usually applied with a mineral finish to provide UV protection and additional weather resistance.
Felt roofing can last 10 to 20 years, depending on the quality of the materials used and the level of maintenance. It is well suited for smaller structures like garages, extensions, and garden sheds but is also used in larger commercial settings.
What do you need?
Applying the Overcoat system to an existing felt roof surface doesn't require a primer or any fibreglass reinforcement. If the existing roof surface is damaged or cracked however you may need to apply the Sharkseal roofing adhesive.
Overcoat System
The Overcoat hybrid polymer roofing system is available in two sizes (7kg and 21kg) and over 20 different colours. The standard in stock colour is Merlin Grey, if you choose another colour please allow up to 5 working days for delivery.
Optional
Sharkseal
This is only required if you have any cracks or splits in the surface that need repairing before applying the Overcoat resin system.
Preparation
Any dirt, soil or other contaminants must be removed from the roof’s surface before installing the Overcoat system. After the initial cleaning, the surface should be power washed and rinsed to remove all residual dirt and contaminates after which the surface should be dried.
Any loose or blistered felt needs to be cut open and investigated, checking and replacing any damaged roof deck. If the roof surface is damaged you need to fill any splits with the Sharkseal multi-surface sealing adhesive and allow to cure for 24 hours before applying the Overcoat system.
If you have had a previous repair done on the felt roof and are unsure of the material that was used, then an Overcoat adhesion test kit should be purchased and completed. Apply the kit to a 250mm x 250mm area and allow 7 days for a complete cure. After the curing period is over, test the area by cutting a cross into the coating and applying tape to pull. If the Overcoat stays adhered then the test has been successful. Each test should be photographed or videoed before and after.
Check the weather
Before starting any Overcoat roofing project it's important to check the weather conditions and try to schedule your work around at least two days of good weather. Overcoat needs to be applied onto a dry surface and can be used in temperatures from 5°C and upwards.
Application
Once the surface preparation has been completed you can apply the Overcoat system with a standard roller or brush at a rate of approximately 1.2 kg per square metre. The Overcoat layer will become instantly watertight and can immediately withstand rainfall. After 24 hours the surface can take foot traffic and a full cure of the system will take around 7 days.
Curing times
Times will vary due to temperature and on-site conditions.
Waterproof
Touch dry
Walkable
Full cure
If a second coat is required then this needs to be applied at least 24 hours after the first layer. Application is the same as the first layer by roller or brush at a coverage rate of 1.2 kg / per m sq, to the full roof area.
Need some help?
Give us a call, request a callback or browse our support section for more information on Overcoat.
