DEKS FlashSeal is a high-performance emergency repair and maintenance solution designed for the sealing, protection and repair of roof flashings and other roofing coverings. Formulated for superior adhesion to a wide range of materials including brickwork, slate, concrete, stainless steel, EPDM and more, it provides a simple and effective way to restore waterproof integrity to ageing or damaged roofing surfaces.
FlashSeal bonds securely to a variety of substrates and is particularly well-suited to bitumen-based products, making it an excellent choice for use on felt roofs, flashing joints and roof penetrations. Once cured, it forms a durable, watertight layer that provides long-term protection against weathering, moisture and UV exposure.
Applied in a thin 1.5mm coating, FlashSeal can bridge and seal cracks or tears up to 5mm wide, preventing water ingress and further deterioration. It hardens quickly to create a fully waterproof seal, ensuring fast, reliable performance even in challenging site conditions.
Each 1.13kg (750ml) tin provides coverage of approximately 0.5m², making it ideal for targeted roof flashing repairs and small-area treatments. Whether used as part of routine maintenance or for rapid leak repairs, DEKS FlashSeal delivers dependable, professional-grade results with minimal effort.
FlashSeal ensures excellent adhesion to various covering materials, brickwork, calcareous sandstone, slate, concrete, fibre concrete, plasterboard, bitumen/tar, roof felt, cut glass, wood, particle board, glass-fibre reinforced polyester, EPDM film, PC film, hard PVC, aluminium, anodised aluminium, powder-coated aluminium, galvanised sheets, zinc-plated sheets, steel, galvanised steel, stainless steel, copper, brass, zinc and lead.
What you need to know
Delivery charges
Delivery Access
Delivery times
Failed deliveries are chargeable
Damaged & missing Items
Do not install purchased items if you have a query with the product (e.g. if you need to query damage that occurred during transit).
Delivery
How much does delivery cost?
Delivery charges will vary and will depend on the manufacturer, weight, size and delivery location. The cost is automatically calculated when you add items to the shopping basket.
How long will I wait for my delivery?
The estimated delivery times are shown on each product page, we will email you each step of the way to keep you informed. The majority of products can be delivered within 3-5 working days.We will advise you if the delivery period is different from than stated on our website.
Do you offer next day delivery?
If a product is available with next day delivery, this will be displayed on the product page or in the basket. If you have a particular item that you require quicker than the guide on our website, please contact our sales team on 01858 455055 during office hours, they will be able to confirm whether a quicker delivery is possible.
What if my delivery doesn't turn up on time?
Please contact our sales office on 01858 455055 or email sales@roofgiant.com and we will advise on the status of your order.
Do you offer free delivery if I spend a substantial amount?
Not as standard, we show the delivery charges separate once you go to the checkout so it is clear what you are paying for the products and delivery costs. If you are ordering larger quantities please contact out sales team who will be able to confirm if this is possible.
Do you deliver on weekends?
Not as standard, our deliveries are made Monday to Friday. If you do need an urgent Saturday delivery please contact out sales team on 01858 455055 during office hours who will be able to confirm. This will incur a premium charge if possible.
Do you deliver to Northern Ireland/Guernsey/The Scottish Highlands/Isle of Wight?
Some suppliers/couriers will deliver to these areas but not all, please contact our sales team on 01858 455055 or email sales@roofgiant.com during office hours for confirmation. If we are able to deliver the product you require, additional transport costs will apply, we will be able to confirm this to you. These additional costs are based on the manufacturer, distributor or courier providing the shipping on our behalf.
Do you deliver to Republic of Ireland, Europe and Rest of World?
No, unfortunately we nor our suppliers can deliver outside of Great Britain (and Northern Ireland in some instances).
What if my delivery doesn't turn up on time?
Please contact our sales office on 01858 455055 or email sales@roofgiant.com and we will advise on the status of your order.
Returns Policy
Important: Please do not send goods back before speaking to our sales office.
📞 01858 455055 | ✉️ sales@roofgiant.com | 💬 Live chat
We recommend you take photos of the goods and packaging before returning, as this may be required for courier claims.
Your Right to Cancel
Returns After 14 Days
Refunds & Costs
Exclusions & Brand Policies
👉 For full details, including supplier-specific terms, please see our Returns & Refund Policy.