Installing PVC guttering is one of the most straightforward home improvement jobs you can tackle yourself. Whether you are replacing old guttering or fitting a new system on an extension, this step by step guide covers everything you need to know, from planning and preparation through to fitting the downpipe and testing the system.
This guide covers standard PVC guttering systems from FloPlast, Osma, and Marshall Tufflex. The process is the same for half round, square line, ogee, and deepflow profiles.
Tools and Materials You Will Need
Tools:
Ladder (ensure it is EN131 rated and has a stabiliser bar), pencil, tape measure, spirit level, string line, hacksaw or fine tooth saw, file or sandpaper, screwdriver or drill with screwdriver bit, plumb line or plumb bob, silicone lubricant spray, safety goggles, and gloves.
Materials:
Gutter lengths, fascia brackets, union brackets, running outlet or stop end outlet, stop ends (left and right hand for ogee), external and internal angles if needed, downpipe lengths, downpipe clips, offset bends for the swan neck, and a pipe shoe at the bottom. If your fascia board is in poor condition, replace it before starting.
Not sure which system you need? Check our guide to PVC guttering profiles or call us on 03330 151860 and we will help you work out exactly what you need.
Step 1: Plan Your Installation
Before you buy anything, measure the full length of the fascia where the guttering will be fitted. Sketch a simple plan showing where the gutter runs, where the downpipes will be, and where any angles or junctions are needed.
Key measurements:
The total length of gutter needed (add 10% for cuts and waste). The number of fascia brackets (one every 600mm for half round and square, one every 500mm for ogee and deepflow). The number of union brackets (one at every joint between gutter lengths). The number of stop ends (one at each open end). The number of angles (internal or external, 90 degree or 135 degree). The length of downpipe from the gutter outlet to the drain or ground.
Choosing the right fall:
PVC guttering must have a slight fall (slope) towards the outlet so water runs to the downpipe. The recommended fall is 3mm per metre of gutter run. So for a 6 metre run, the high end should be 18mm higher than the outlet end. This is not visible to the eye but makes a big difference to water flow.
Step 2: Remove Old Guttering
If you are replacing existing guttering, remove the old system carefully. Start by removing the downpipe from the bottom up, then remove the gutter lengths by unclipping them from the brackets. Finally remove the old brackets from the fascia. Fill any old screw holes with exterior filler and let it dry before fitting the new brackets.
Check the fascia board while it is exposed. If it is rotten, soft, or damaged, replace it before fitting new guttering. Guttering is only as strong as the fascia it is fixed to.
Step 3: Fit the Running Outlet
The running outlet is where water exits the gutter and drops into the downpipe. Fit this first as it sets the lowest point of the gutter run.
Hold a plumb line against the fascia directly above the drain or where you want the downpipe to discharge. Mark the position on the fascia with a pencil. Fix the running outlet no more than 50mm below the roof tiles using two 25mm x 5mm round head screws. The back edge of the tiles should overhang the gutter by about 25 to 50mm to allow water to drip directly into the channel.
Step 4: Fit the First Bracket and Set the Fall
At the opposite end of the gutter run from the outlet, fit the first fascia bracket. This will be the highest point. Position it no more than 150mm from the end of the run (or from a stop end).
Use a string line tied between the top of the running outlet and the top of the first bracket. Use a spirit level to check the string is level, then lower the outlet end to create the 3mm per metre fall. For example, on a 6 metre run, the outlet should be 18mm lower than the first bracket.
The string line now gives you a guide for all the intermediate brackets.
Step 5: Fit the Remaining Fascia Brackets
Working from the first bracket towards the outlet, fit the remaining fascia brackets at even intervals along the string line. Use the following maximum spacings:
Half round guttering (112mm to 114mm): brackets every 600mm maximum.
Square line guttering (114mm): brackets every 600mm maximum.
Ogee guttering (110mm to 128mm): brackets every 500mm maximum.
Deepflow guttering (115mm): brackets every 500mm maximum.
Always fit a bracket within 150mm of any fitting (union, angle, stop end, outlet). Each bracket should be fixed with two 25mm x 5mm round head brass or zinc plated screws.
Step 6: Fit the Gutter Lengths
Before fitting, apply silicone lubricant spray to all rubber seals on the gutter fittings. This makes clipping the gutter in much easier and helps with expansion and contraction over time.
Starting at the outlet, fit the first length of gutter by tilting it to sit under the back clip of the bracket, then push down at the front to snap it into position. PVC gutter expands and contracts with temperature, so always fit the gutter to the expansion mark indicated on the fitting. Do not push the gutter tight against the stop inside the fitting.
At the other end of the first length, fit a union bracket to the fascia, then clip the next length of gutter into the union. Continue joining lengths in the same way until the full run is complete.
Cutting gutter to length: Mark the cut line with a pencil, then cut with a hacksaw or fine tooth saw. File or sand the cut edge smooth to remove any burrs. Always cut from the front face of the gutter to get a cleaner edge.
Step 7: Fit Stop Ends and Angles
Fit stop ends at each open end of the gutter run. For half round and square guttering, stop ends are universal. For ogee guttering, stop ends are handed (left and right) so check you have the correct ones.
If the gutter turns a corner, fit an internal or external angle piece. Internal angles are used where the gutter turns into the building (like an internal corner of an L shaped house). External angles are used where the gutter turns outward. Always support angles with a bracket within 150mm on each side.
Step 8: Fit the Downpipe
The downpipe connects the running outlet to the drain below. In most cases you will need a swan neck (two offset bends) to bring the downpipe from the outlet back to the wall face.
Making a swan neck: Fit an offset bend to the bottom of the running outlet. Hold a second offset bend against the wall and measure the distance between them. Cut a short piece of downpipe to bridge the gap. Connect the two bends with the pipe to form the swan neck.
From the bottom of the swan neck, run the downpipe straight down to the drain. Fix the downpipe to the wall using pipe clips at maximum 1.8 metre intervals. Use two 32mm x 6.5mm round head screws per clip. If fixing into masonry, use wall plugs.
At the bottom of the downpipe, fit a pipe shoe to direct water away from the wall and into the drain. The shoe should sit approximately 25mm above the drain grate or ground level.
Step 9: Test the System
Once everything is fitted, test the system by pouring water into the gutter at the highest point (furthest from the outlet). The water should flow steadily towards the outlet without pooling anywhere. Check every joint for drips. If a joint leaks, unclip the gutter, clean the seal, apply fresh silicone lubricant, and reclip.
Check the downpipe discharges correctly into the drain. If the downpipe connects to underground drainage, you may need a rainwater adaptor to connect the 68mm downpipe to 110mm drainage pipe.
Common Mistakes to Avoid
Not enough fall: If the gutter is level, water will sit in it and eventually overflow. Always maintain at least 3mm per metre of fall towards the outlet.
Brackets too far apart: This causes the gutter to sag between brackets, especially when full of water or snow. Stick to the recommended spacings.
Ignoring expansion gaps: PVC gutter expands up to 3mm per metre in warm weather. Always fit to the expansion line marked on fittings. If you push gutter tight against the stops, it will buckle in summer.
Tiles not overhanging the gutter: If the roof tiles end before the gutter, water will run down the fascia instead of into the channel. The tile edge should overhang into the gutter by 25 to 50mm.
Not replacing damaged fascia: Guttering fixed to rotten or soft fascia will eventually pull away from the building. Always replace damaged fascia before fitting new guttering.
Mixing brands without adaptors: Different PVC guttering brands are not always directly compatible. If you need to join FloPlast to Osma or Marshall Tufflex, use a gutter adaptor.
Which PVC Guttering System Should I Use?
Half Round the most common profile for UK homes. Suitable for the majority of domestic properties. Available in 112mm (FloPlast), 112mm (Osma RoundLine), and 114mm (Marshall Tufflex).
Square Line a modern angular profile with higher flow capacity than half round. Suits new builds and contemporary homes.
Deepflow designed for larger roof areas or high rainfall regions. Carries significantly more water than standard profiles.
Ogee a decorative S shaped profile for period properties and Victorian terraces.
Mini purpose built for sheds, garages, porches, and outbuildings.
Not sure which one you need? Call us on 03330 151860 and our team will help you choose the right system for your property.
PVC Guttering Installation FAQ
Can I install PVC guttering myself? Yes. PVC guttering is designed for DIY installation. It is lightweight, easy to cut, and uses a simple clip fit system. No specialist tools are required beyond a hacksaw, drill, and spirit level.
How long does it take to install PVC guttering? A typical semi detached house with two straight runs and two downpipes can be completed in 4 to 6 hours by one person. More complex layouts with multiple angles and outlets will take longer.
Do I need scaffolding? For single storey properties, a good quality extension ladder with a stabiliser bar is sufficient. For two storey properties, scaffolding is recommended for safety, especially if you are working alone. If using a ladder, never overreach and always have someone holding the base.
Can I fit new guttering over old brackets? No. Old brackets should always be removed and replaced. Different systems use different bracket designs, and old brackets may not be in the correct positions for the new system. Old screw holes should be filled before fitting new brackets.
What screws should I use for gutter brackets? Use 25mm x 5mm round head brass or zinc plated screws for fascia brackets. Use 32mm x 6.5mm round head screws for downpipe clips. For masonry fixings, use appropriate wall plugs.
How do I cut PVC guttering? Mark the cut line with a pencil. Use a hacksaw or fine tooth saw to cut through the gutter. File or sand the cut edge smooth. Always cut from the front face for a cleaner finish.
Buy PVC Guttering from Gutters.co.uk
At Gutters.co.uk we stock the UK's widest range of PVC guttering from FloPlast, Osma, and Marshall Tufflex. Every profile, every fitting, every colour, all available for fast UK delivery. If you need help working out what you need for your installation, call us on 03330 151860 and our team will talk you through it.