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IMPORTANT: This Alumasc product is made to order and is non-returnable. Please ensure all specifications are correct before placing your order.
Available in 75mm and 100mm outlet sizes. Harmer Anti Vortex Aluminium Retro Gulley Drainage Outlets are a cost-effective and efficient flat roof drainage upgrade that fit perfectly within existing outlets and pipework. Easy to install with minimal disturbance, a retro-gully is ideal for any type of warm roof refurbishment and can be used with any flat roof waterproofing system.
Designed to accommodate variations on pipe internal diameter from PVC through to cast iron pipe systems. There is no need to remove the old rainwater outlet and the use of an anti vortex outlet will also increase flow performance regardless of pipe diameter downsizing.
The tail pipe, cut to the required length, is simply inserted through the existing outlet into existing pipework and sealed by means of the Harmer Roof AV special multi-fin pipe seal. This seal creates a watertight junction between existing pipework and the Retro-Gully tail pipe. The outlet body’s wide fixing flange incorporates concentric grooves which enhance the bond with roofing felts or asphalt.
An LM6 aluminium silicon clamping ring also has a ridged under-surface for an improved bond with roofing membranes. Two sealable ports in the outlet body are designed for injection of PU foam to fill the void between the old and new outlet.
For storage advice, please see our Downloads section. This is particularly important for powder coated products.
To discover how Alumasc products can enhance your home, and view useful case studies, click here.
What you need to know
Delivery charges
Delivery access
Date and time of delivery
Failed deliveries are chargeable
Damages & missing items
Incorrect product delivered
AWMS will not accept any liability for any consequential costs associated with late deliveries, failed deliveries or incorrect goods being delivered.
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.