Shed Gutter Guide to Choosing Sizing and Installing Gutters

Every shed roof sheds a lot of water. A 6m x 9m roof catches more than 50 litres in a single 1mm shower, and a heavy WA downpour can multiply that many times over in minutes.

Without a shed gutter, that water falls straight off the roof edge. It scours the soil along the walls, pools against the slab and splashes back onto the cladding. Over time, you get a cracked or sinking slab, rust around the fixings and damp inside the shed.

The fix is simple when it’s planned properly. This guide covers the right gutter type for your shed, how to size it, how to install it and how to keep it working, whether you’re adding gutters to a backyard shed or speccing a new build with one of WA’s established sheds Perth suppliers.

Here’s Everything You Need to Know in Under a Minute

Table of Contents

Do Sheds Need Gutters?

Most sheds do. If your shed sits on a concrete slab, stands within a metre or two of a fence, house or garden bed, or stores anything you want kept dry, a gutter is worth fitting.

You can usually skip gutters on a very small garden shed (under about 3m x 2m) sitting on pavers or gravel, well away from other structures. The runoff volume is low and has somewhere harmless to go.

For larger residential sheds Perth homeowners use as garages and workshops, gutters do three jobs:

• Protect the slab: Runoff concentrated along one edge washes out the soil beneath, which can crack or tilt the slab.
• Keep the inside dry: Water pooling at the base wicks in under doors and adds to internal humidity. Gutters are one of the 11 ways to protect your shed from moisture.
• Collect free water: A shed roof is a ready-made catchment for a rainwater tank.

Types of Shed Gutters and Which Suits Your Shed

The right profile depends on your roof area, roof style and how the shed is used. Here are the five profiles you’ll see on Australian sheds.

Quad and Square Line Gutters

Quad (with its curved front) and square line gutters are the standard profiles on homes and residential sheds. They hold more water than mini-line systems and come in a wide range of steel colours, so they’re the default choice for garages and workshops.

Slotted Fascia Gutters

Slotted gutters have small slots along the front face. If the gutter blocks or overflows, water escapes outwards through the slots instead of backing up into the shed. They need more frequent downpipes because the profile is narrow, and leaves can build up faster.

Half Round Gutters

Half round gutters have a curved base that drains well and resists debris build-up. They suit larger sheds and heritage-style buildings, but they cost more than square profiles of a similar capacity.

Wide Custom Gutters for Large Sheds

Large farm and machinery sheds often use extra-wide custom gutters. The bigger profile carries water to downpipes at each end of the shed, so there are no downpipes along the open front for machinery to hit. This is common on rural sheds Perth farmers use for hay and equipment storage.

Box Gutters

A box gutter sits inside the roof line, usually in the valley where two roofs meet or behind a parapet wall. Multi-span industrial sheds and buildings with joined gable roofs often need one. Because a box gutter overflows inside the building if it fails, it must be generously sized and fitted with overflow outlets. Your roof style decides whether you need one, so it’s worth reviewing common shed roof designs early in planning.

What Is the Best Shed Gutter Material?

For most Australian sheds, steel is the best choice. Here’s how the three common materials compare.

• PVC: Cheap and easy to cut, but WA sun breaks it down. Expect it to fade, become brittle and sag sooner than steel.
• Aluminium: Light and corrosion-resistant, which suits coastal sites. It dents easily and can corrode where it touches steel roofing.
• ZINCALUME® and COLORBOND® steel: Strong, long-lasting and colour-matched to your roof and walls. This is the standard for steel sheds.

Matching your gutter to your roof sheeting also avoids corrosion between incompatible metals. If your shed is clad in COLORBOND® steel, a matching gutter keeps it looking uniform and performing the same way. The benefits of COLORBOND sheds apply equally to the gutters. Follow the manufacturer’s COLORBOND maintenance guidance to protect the finish over time.

How to Size Your Shed Gutter and Downpipes

Undersized gutters overflow in heavy rain, no matter how well they’re installed. Sizing comes down to five checks.

Roof Area and Rainfall Intensity

Work out the roof area that drains into each gutter (length x half the span for a gable roof). Then check how intense rainfall gets where you live. The Bureau of Meteorology rainfall maps show how rainfall varies across the state. Short, intense storms are what gutters must handle, not the annual total.

Gutter Fall

Gutters need a slight slope so water runs to the outlet instead of sitting in the channel. The National Construction Code gutter provisions set a minimum fall of 1:500 for eaves gutters (unless fixed to a metal fascia) and 1:100 for box gutters.

In practical terms, 1:500 is about 6mm of drop for every 3 metres of gutter. Too little fall leaves standing water. Too much looks crooked from the ground.

Bracket Spacing

The code allows eaves gutter brackets up to 1.2m apart. For sheds, closer is better. Spacing brackets 600mm to 1m apart stops sagging under water weight, leaf build-up and the odd ladder leaning against the gutter.

Downpipe Spacing and Size

Each downpipe should serve no more than 12 metres of gutter. On a shed longer than 12m, add a downpipe in the middle or at both ends. Most residential sheds use 90mm round or 100mm x 50mm rectangular downpipes. Large rural and industrial sheds often step up to 150mm stormwater pipe.

Overflow Protection

Plan where water goes when the gutter is overwhelmed. Slotted gutters, rainheads with overflow spitters or a gap between the gutter and fascia all let excess water spill outwards, away from the walls.

How to Install a Shed Gutter Step by Step

Fitting a gutter to a small shed is a manageable DIY job. Larger and higher sheds are a different matter, so be honest about the height and length involved.

What you’ll need: gutter lengths, brackets, stop ends, outlets (pop-outs), downpipe and bends, gutter sealant, roofing screws, a drill, tin snips, a tape measure, a level, a string line and a sturdy ladder or scaffold.

1. Measure and plan. Measure the roof edge and decide where the downpipe will go. Place it where water can drain to a stormwater point, soak well or tank.
2. Set the fall. Mark the high point at the far end, about 25mm below the roof sheeting. Mark the low point at the outlet end using the 6mm per 3m rule. Snap a string line between them.
3. Fix the brackets. Screw brackets to the fascia or rafter ends along the string line. On sheds without fascia boards, use over-strap brackets fixed to the roof sheeting and purlins.
4. Cut the outlet. Mark and cut the hole for the pop-out on the ground, then fit and seal it.
5. Fit the gutter. Clip the gutter into the brackets. Where two lengths join, overlap them by about 150mm in the direction of flow, then seal and rivet the joint.
6. Fit stop ends. Seal and rivet a stop end at each closed end.
7. Connect the downpipe. Attach bends and the downpipe to the outlet, fix it to the wall with clips and run it to your drainage point.
8. Test it. Run a hose at the high end and check for leaks, sags and standing water.

Working at height is the biggest risk in the job. Keep three points of contact on the ladder, never overreach and don’t work alone. If your shed is over a single storey or longer than about 12m, an experienced shed builder is the safer option.

Connecting Shed Gutters to a Rainwater Tank

A shed roof is one of the easiest places to harvest rainwater. To get clean, usable water:

• Fit leaf guards or mesh over the gutter to keep debris out.
• Install a first flush diverter on the downpipe. It discards the first, dirtiest water that washes dust and droppings off the roof.
• Use a rainhead with a screen above the tank inlet as a second filter.
• Place the tank close to the downpipe on a level, compacted base.

If you’re planning taps, a sink or a toilet in the shed, read our factors to consider in shed plumbing before you plan your tank layout.

Shed Gutter Maintenance That Prevents Problems

Gutters only work when they’re clear. A short routine keeps them performing for decades.

• Clean twice a year in late autumn and spring, and after major storms. Clean more often if trees overhang the shed.
• Hose unwashed areas. Rain doesn’t reach the underside and back of the gutter, so salt and grime build up there. Wash them at least every six months, more often near the coast.
• Check joints and outlets for leaks and reseal any that have cracked.
• Tighten or replace loose brackets before the gutter starts to sag.
• Watch for standing water. It means the fall has shifted or the outlet is blocked.

A gutter that overflows behind the fascia lets water into the shed walls, which adds to internal humidity. If you notice damp inside, also look at airflow, as our guide on how to stop condensation in a shed explains.

How Much Does Shed Guttering Cost?

Gutters are a small share of your total shed cost, but their price still varies widely. The main factors are:

• Gutter length and profile: Wide custom and half round profiles cost more per metre than quad or square line.
• Material: PVC is cheapest upfront. COLORBOND® steel costs more but lasts far longer.
• Number of downpipes and fittings: Every outlet, bend and rainhead adds cost.
• Height and access: Taller sheds may need scaffolding or an elevated work platform.
• Stormwater connection: Trenching and pipework to a soak well or drain can cost as much as the gutters themselves.

Building gutters into a new shed is almost always cheaper than retrofitting them later, as the brackets, fall and downpipe positions are planned with the frame. For a full breakdown of shed prices in WA, see our pricing guide.

Shed Gutter Requirements by Shed Type

Residential Sheds and Garages

Quad or square line steel gutters with 90mm or 100mm x 50mm downpipes suit most backyard sheds and garages. Match the colour to the house and direct the water away from neighbouring fences.

Rural and Farm Sheds

Large farm sheds benefit from wide gutters with downpipes at the ends, keeping the open front clear for tractors and hay handling. A shed roof this size can fill a large rainwater tank for stock and wash-down water.

Commercial and Industrial Sheds

Large roofs on commercial sheds Perth businesses operate from need high-capacity gutters, often with box gutters between spans. Stormwater usually has to connect to an approved drainage system, so the gutter design is part of the building approval.

Mining Sheds

Remote sites face intense, short storms and red dust. For mining sheds Perth projects, heavy-duty steel gutters, generous downpipes and easy access for cleaning are essential.

Why Choose Action Sheds for a Properly Guttered Shed

Action Sheds is a family-run business based in Perth, supplying and building thousands of steel sheds Australia-wide for more than 20 years. We specialise in every shed type, from domestic workshops and garages to farm, commercial, industrial and mining buildings.

Gutters and downpipes are planned into every design from the start. That means the profile, fall, bracket spacing and downpipe positions suit your roof area and site, rather than being added as an afterthought.

You can map out your shed, including roof style and size, with our custom shed designer, then talk to our team about the right gutter and drainage setup.

Frequently Asked Questions

Can You Put Gutters on an Existing Shed?

Yes. Most metal sheds can be retrofitted with gutters. If there’s no fascia, use over-strap brackets fixed through the roof sheeting into the purlins. Check there’s clearance along the wall for the gutter and a downpipe, and somewhere for the water to drain.

Should Gutters Be Nailed or Screwed In?

Screwed. Screws grip far better than nails, resist wind uplift and won’t work loose as the steel expands and contracts in the heat. Use corrosion-resistant roofing screws compatible with your gutter material.

What Are Good Small Gutters for a Shed?

Mini-line gutters of around 76mm suit small garden sheds and cubby houses. For a shed with a slab or a roof wider than about 3m, step up to a standard quad or square line profile for extra capacity.

How Can I Make Gutters for My Shed?

The simplest option is a gutter kit, which includes the gutter, brackets, stop ends, an outlet and a downpipe. Homemade gutters from timber or cut PVC pipe rarely seal well or last in WA conditions. A proper kit costs little more and performs far better.

Keep Water Where It Belongs

A well-planned shed gutter protects your slab, keeps your shed dry and turns your roof into a water supply. Choose a steel profile sized for your roof, set the fall at 1:500, keep brackets close and add a downpipe for every 12 metres of gutter.

If you’re planning a new shed, gutters and drainage are far easier to get right at the design stage than to retrofit later.