Our 115mm cast iron guttering is in fact one of the most popular sizes in the Alumasc Apex Heritage range and a very natural choice for standard residential roofs, period properties, renovations and smaller commercial buildings.
Also known as 4.5-inch cast iron guttering, this Plain Half Round system gives you more rainwater capacity than the smaller 100mm profile without looking overly heavy on a typical house.
Gutter lengths are supplied in 1.83m sections, with matching unions, 90° and 135° angles, stop ends, fascia brackets, rise-and-fall brackets and both top-fix and side-fix rafter brackets available.
You can also choose between 65mm and 75mm outlets, including running outlets and internal or external drop-end outlets. From there, complete the rainwater run with our matching cast iron downpipes or add one of our cast iron hoppers where the roof layout needs a hopper head.
The Apex Heritage range is available factory painted black, primed ready for finishing on site, or in selected custom RAL colours. Popular black products are generally available for next-working-day delivery when ordered before 11:30am, subject to stock.
Not sure whether 115mm is right for your roof? Read our Cast Iron Guttering Sizes Explained guide, or read the full install guide.
Alumasc Apex 115mm (4.5") Half Round Cast Iron Gutter 1.83m Length - Black
Alumasc Apex 115mm (4.5") Half Round Cast Iron Fascia Bracket - Black
Alumasc Apex 115mm (4.5") Half Round Rise & Fall Bracket for Cast Iron Gutter - Black
Alumasc Apex 115mm (4.5") Half Round Side Fix Rafter Bracket for Cast Iron Gutter - Black
Alumasc Apex 115mm (4.5") Half Round Top Fix Rafter Bracket for Cast Iron Gutter - Black
Alumasc Apex 115mm (4.5") Half Round Cast Iron External Stop End - Black
Alumasc Apex 115mm (4.5") Half Round Cast Iron Internal Stop End - Black
Alumasc Apex 115mm (4.5") Half Round Cast Iron Gutter Union - Black
Alumasc Apex 115mm (4.5") Half Round Cast Iron 90 degree Gutter Angle - Black
Alumasc Apex 115mm (4.5") Half Round Cast Iron 135 degree Gutter Angle - Black
Alumasc Apex 115mm (4.5") Half Round Cast Iron 65mm (2.5") Gutter Outlet - Black
Alumasc Apex 115mm (4.5") Half Round Cast Iron 75mm (3") Gutter Outlet - Black
Alumasc Apex 115mm (4.5") Half Round Cast Iron 65mm (2.5") Drop End Gutter Outlet - External - Black
Alumasc Apex 115mm (4.5") Half Round Cast Iron 65mm (2.5") Drop End Gutter Outlet - Internal - Black
Alumasc Apex 115mm (4.5") Half Round Cast Iron 75mm (3") Drop End Gutter Outlet - External - Black
Alumasc Apex 115mm (4.5") Half Round Cast Iron 75mm (3") Drop End Gutter Outlet - Internal - Black
Alumasc Apex 115mm (4.5") Half Round Cast Iron Gutter 1.83m Length - Primed
Alumasc Apex 115mm (4.5") Half Round Cast Iron Fascia Bracket - Primed
Alumasc Apex 115mm (4.5") Half Round Cast Iron External Stop End - Primed
Alumasc Apex 115mm (4.5") Half Round Cast Iron Internal Stop End - Primed
Alumasc Apex 115mm (4.5") Half Round Cast Iron 90 degree Gutter Angle - Primed
Alumasc Apex 115mm (4.5") Half Round Cast Iron 135 degree Gutter Angle - Primed
Alumasc Apex 115mm (4.5") Half Round Rise & Fall Bracket for Cast Iron Gutter - Zinc Plated
Alumasc Apex 115mm (4.5") Half Round Side Fix Rafter Bracket for Cast Iron Gutter - Zinc Plated
Alumasc Apex 115mm (4.5") Half Round Top Fix Rafter Bracket for Cast Iron Gutter - Zinc Plated
Alumasc Apex 115mm (4.5") Half Round Cast Iron 65mm (2.5") Gutter Outlet - Primed
Alumasc Apex 115mm (4.5") Half Round Cast Iron 75mm (3") Gutter Outlet - Primed
Alumasc Apex 115mm (4.5") Half Round Cast Iron Gutter Union - Primed
Alumasc Apex 115mm (4.5") Half Round Cast Iron 75mm (3") Drop End Gutter Outlet - External - Primed
Alumasc Apex 115mm (4.5") Half Round Cast Iron 75mm (3") Drop End Gutter Outlet - Internal - Primed
Alumasc Apex 115mm (4.5") Half Round Cast Iron Fascia Bracket - One of 6 CI Standard RAL Colours TBC
Alumasc Apex 115mm (4.5") Half Round Cast Iron Gutter Union - One of 6 CI Standard RAL Colours TBC
Popular black painted and primed cast iron products are usually available for next working day delivery when ordered before 11:30am, subject to stock. Custom RAL colours normally take around 7–10 working days.
For many UK homes, 115mm or 125mm guttering is a common choice. Smaller roof areas such as porches and outbuildings may use 100mm, while larger roofs or longer runs may need 150mm. Roof area, gutter profile and the number of outlets all matter, so it is worth checking before ordering.
Yes. We supply matching cast iron downpipes, hopper heads, brackets, outlets and fittings across the range, so you can put together a complete rainwater system rather than mixing different manufacturers or profiles.
Yes. Alongside painted black and primed finishes, many cast iron gutters, downpipes and hoppers can be supplied in custom RAL colours. Bespoke finishes are usually supplied within 7–10 working days.
Standard products can usually be returned within 30 days of delivery, although returns after the first 14 days may be subject to a restocking or handling charge. Made-to-order and custom-colour items are non-refundable, so it is worth checking sizes and finishes carefully before ordering.
Painted black products arrive with the finished colour already applied and are ready to install. Primed products are intended for projects where you want to apply the final decorative finish on site.
Normally, no. Plain Half Round, Beaded Half Round, Victorian Ogee, Moulded Ogee and Deepflow all use different shapes and fittings. It is best to keep the gutter lengths, unions, angles and outlets within the same profile and size.
Send us a photo and a few measurements. The overall width, depth, profile shape and downpipe diameter are usually enough to narrow it down and help identify the closest matching system.
You can buy individual components. We stock gutter lengths, unions, angles, stop ends, outlets, brackets, downpipes, bends, shoes, hopper heads and sundries separately, which is useful for repairs as well as complete installations.
Yes. If you have plans, elevations or even a marked-up sketch, send them over and we can help work through the likely gutter lengths, outlets, downpipes, angles and fittings required.
Cast iron guttering does not need constant attention, but it does need checking. The expensive problems usually start as small ones: a handful of leaves sitting over an outlet, one...
Replacing gutters on a listed building seems like a simple maintenance job. Sometimes it is. But gutters, downpipes, brackets and hopper heads can all play an essential part of the...
Repairing Cast Iron Guttering: Leaks, Rust, Cracks & Failed Joints A leaking cast iron gutter doesn't always mean the whole gutter system needs replacement. Often the iron itself will still...
A 100mm diameter downpipe will have a cross-sectional area that is almost 2.4 times larger than that of a 65mm diameter downpipe. However, it doesn't necessarily mean that a 100mm...
A properly applied paint system on cast iron guttering can go around five to seven years before further attention may be needed. That’s a pretty good reminder that painting cast...
If you’re fitting cast iron guttering, around 900mm between brackets is the normal starting point. But that isn’t the whole story. Cast iron is heavy, especially once the gutter is...
Cast aluminium is probably the closest modern alternative to genuine cast iron guttering. Put a textured black cast aluminium system on a period property and, particularly from ground level, it...
Replacing old cast iron guttering sounds straightforward until you actually stand underneath it and realise you don’t know what profile it is. Half Round? Beaded Half Round? Victorian Ogee? Moulded...
