Square, Half-Round or Ogee Guttering?

How the three profiles differ

A gutter profile is the shape of its cross-section. A half-round gutter is a semicircle, open at the top. It is the oldest design, in cast iron on old houses and plastic on newer ones, and is the cheapest and most widely stocked. Because the curve has no corners, it sheds leaves and silt reasonably well and is easy to clean.

A square gutter has a flat back, a flat bottom and a flat front, like a box. It looks neat against a flat fascia and suits contemporary houses, and it can hold more water than a half-round of the same width, since the section is fuller. An ogee (sometimes written OG) gutter has a front face with a double curve, like a classical moulding. It looks right on a period house with a deep fascia, and is often fitted straight to the board with no separate bracket showing.

Which suits which house

Match the profile to the architecture, as you would a window:

• Cottages, farmhouses and houses with exposed rafter feet: half-round, in black or brown, looks right.
• Victorian and Edwardian terraces: ogee or half-round in cast iron or a cast-iron look, in black. See cast iron guttering on period homes.
• 1960s to 1990s estate houses: half-round or square, in white or brown, to match the fascia.
• Modern builds, flat fascias, box-style extensions: square, often in grey or black.
• Flat-roofed extensions with a deep fascia: square or deep-flow, to carry more water.

Colour also plays into it, and whether gutters should match the fascia and soffit goes through the options.

Looks are not everything, and each shape has quirks. Half-round gutters have a narrow bottom, so heavy debris collects in the lowest line and a small sag turns it into a pond. Square gutters have corners where moss and silt settle, so they need cleaning with a scoop that reaches into the angle. Ogee gutters hide their brackets, which looks neat but makes it harder to see a failing fixing from the ground. None of this rules a profile out, but it is useful to know what you are living with.

Joints and corners also differ. Square and ogee systems need purpose-made internal and external corners, and a house with many corners, bays or extensions will need more of them, each of which is a joint that can leak. A plain half-round run with few corners has fewer weak points, and that counts when you are choosing for an awkward roof plan.

Capacity, fixing and materials

Capacity depends on the size and shape of the channel, the fall and the number of outlets. A wide or deep gutter carries more than a narrow one. Where a big roof drains to a single short run, a deep-flow or square profile, or an extra downpipe, stops overflow in heavy rain. Our page on what size guttering you need gives the reasoning behind the sizes.

Fixing is another factor. Half-round and square gutters hang on brackets screwed to the fascia or the rafter ends. Ogee gutters are fixed to the face of the board, so the fascia must be flat, sound and wide enough to take the screws. If the board is rotten, fix that first; see rotten fascia boards. Materials vary too. uPVC comes in all three profiles. Aluminium comes in most, including continuous lengths formed on site. Cast iron is heavier and used for period work. The comparison of materials is in the comparison of uPVC, aluminium and cast iron.

Changing the profile when you replace

When old guttering is replaced you do not have to copy the old shape. A change to square may suit an extended house, and a switch from ogee to half-round is common when the fascia has been capped. Make sure the downpipes, outlets and stop ends are all from one system, since parts from different makers rarely fit tightly. Old brackets also need renewing, not re-using, because a new run on a worn bracket will sag.

On a protected building, a change of material or look can need approval from the conservation officer, whereas like-for-like replacement is usually simple.

Our free survey photographs your roofline and tells you which profile suits your fascia, the roof area and the style of the house. You get fixed written figures afterwards. Typical ranges sit on the gutter replacement cost page, and the wider guttering, soffits and fascias hub lays out how we work. Profile and size are settled together on site, so nothing is guessed from a photograph alone.