How to install plastic guttering

How to install plastic guttering

Sebastian, self-taught DIY-er, Exeter

Guide written by:

Sebastian, self-taught DIY-er, Exeter

192 guides

Whether you're replacing an old zinc or aluminium gutter or just need to fit a new PVC gutter, just about any DIYer should be able to install their own plastic guttering by following a few basic rules. From measuring your slope to installing the downpipe, read on to find out how to install plastic guttering.

Important features

  • Calculating gutter slope
  • Installing gutter brackets
  • Installing the guttering
  • Installing the downpipe
  • Fitting gutter accessories
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Collecting and draining rainwater from your roof


Designed to protect the outer walls of your house from water infiltration, guttering is an essential system that collects and drains rainwater down from your roof and through a downpipe. Inexpensive to buy, plastic (or PVC) gutters can also be attractive. 

Available in a range of different colours (such as white, sand or grey) plastic gutters can be made to blend in perfectly with any type of façade.This type of system can be glued into place but is more commonly slotted together, in which case the gutters are equipped with rubber seals to make them watertight. In either case, you don't need any special tools which is not the case with zinc, aluminium or copper guttering – this makes PVC gutters the ideal system for DIYers!

Parts of a gutter system

Parts of a gutter system

Choosing a gutter size

In order for the rainwater to drain away easily, you'll need to ensure that your gutter system is the right size for your roof:

  • 5-inch gutters are the most common option in the UK and are generally acceptable for most residential applications;
  • 6-inch gutters, while only an inch larger, can hold considerably more water and are best for very large, steep roofs or areas with a lot of rainfall.

Downpipe sizes

The same goes for your downpipe which must match the size of your gutters:

  • a standard 5-inch gutter system should generally be fitted with a 2x3" downpipe.
  • a 6-inch gutter system should be fitted with a 3x4" downpipe.

Gutter installation

Adhesive sealant

In this case, all gutter components are assembled with the use of a special PVC adhesive. This system is then hung in the gutter hangers in such a way as to allow the PVC to expand and contract with the outdoor temperature. For long sections of gutters, you will need an expanding union every 8 metres or so.

Snap-together gutters

All gutter components (drop outlet, angles, union brackets) are equipped with rubber seals to ensure your guttering is watertight and allow the PVC to expand. The parts are designed to be simply clipped into place.


  1. Calculating gutter slope
  2. Installing gutter brackets
  3. Installing the guttering
  4. Installing the downpipe
  5. Fitting gutter accessories

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Guttering and downpipe accessories

Calculating gutter slope

In order for your gutter system to drain properly, it has be to installed with a slope of 0.5 cm to 1 cm for every metre of gutter

To work out how much you need your gutter to slope, you simply have to multiply the length of the gutter by the minimum slope (i.e. 0.5 cm per metre). The calculation for a gutter measuring 5 metres in length would therefore be: 5 x 0.5 = 2.5 cm. You can then mark out your gutter slope by fixing a screw into each end of your fascia.

  • Fix your first screw at the end of the fascia opposite the drop outlet. Position the screw 5 cm from the end of the fascia and 3 cm from the top.

  • Fix a second screw at the downpipe end using your slope calculation.
  • Tie a string or brick line between the two screws.

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Fitting the gutter hangers

Fixing the gutters to the fascia

  • Mark out points every 50 cm along your slope line. Ideally, these points should line up with where the fascia is nailed down so that the gutter screws line up with the rafter tails.
  • Screw the brackets into the fascia making sure that they align with your string (using the screw hole at the top of the bracket as the reference point). If your guttering requires a union, place a bracket on each side of the union making sure to leave a gap of at least 5 cm to allow the gutter to expand.

Fixing the gutter to the rafters

In this case, the brackets will be fitted with long arms designed to screw into the sides of the rafter tails (side rafter brackets) or on top of the rafter tails (top rafter brackets). You may have to remove the first row of shingles when installing a gutter in this way. 

  • Fit the fascia bracket with a long rafter bracket.
  • Position the fascia bracket against the rafter tail and ensure that the rafter bracket fits against your roof slope.
  • Screw in the rafter bracket.
  • Position and screw in the fascia brackets.
  • Adjust the height of the brackets to align with the string line.

Fixing the gutter to your roof covering

Strap hangers can be occasionally be used to fix your brackets directly to your roof covering (shingles or corrugated metal).

  • Be sure to choose the right type of strap for your roof and bear in mind that this type of installation can cause leaks.
  • Install a bracket every 50 cm.
  • Line up the top of the brackets with the string line.

Installing the guttering

Preparation and installing the gutter

  • Measure the length of gutter required.
  • Mark this measurement out on your length of gutter if your sections are not already cut to size.
  • Cut the gutter using a hacksaw. It's a good idea to use a cutting guide to ensure that your cut is perfectly straight.
  • File off the end of the gutter using some fine grain sandpaper or the blade of a knife.
  • Lay a thin bead of PVC adhesive inside the stopend or the end of the gutter.
  • Fit the stopend onto the end of the gutter opposite the drop outlet.
  • Hold the stopend firmly in place for a few seconds to ensure it adheres properly.
  • Wipe off any excess glue with a cloth.
  • Fit the gutter with a union if required. The union should be connected in exactly the same way as set out above.
  • Cut a second length of gutter to cover the distance to the outlet.
  • Position the first length of gutter into the brackets with the rim facing outwards.
  • Insert the second length of gutter.
  • Apply PVC tape between your seams.
  • Join your sections of gutter.

Fitting the drop outlet

Fitting the drop outlet
  • Glue a stopend onto the outlet end of the gutter.
  • Wipe off excess glue.
  • Apply PVC adhesive around the outlet seams.
  • Slot the drop outlet into the gutter.

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PVC adhesive

Installing the downpipe


The downpipe should be positioned over the opening of the inspection chamber. The drop outlet is connected to the downpipe in an 'S' shape with the use of two elbows (male/female).

  • Mark out the centre of the downpipe on the wall using a chalk line or a straight edge and pencil.
  • Mark out the position of your pipe clips which should be installed every metre or so.

  • Measure the distance between the elbows.
  • Cut a section of your downpipe to fit the elbows.
  • Mark out the position of all components using a carpenter's pencil.

Assemble all components using PVC adhesive with the exception of the joint between the elbow and the outlet so that the downpipe can be easily removed if required.

  • Drill into the brickwork using a drill or hammer drill fitted with a masonry drill bit.
  • Secure the pipe clips using a hanger bolt and the appropriate wall plugs for your surface.
  • Position the downpipe with the female end pointing up.
  • Insert the male/female elbow into the downpipe.
  • Position the elbow towards the outlet.
  • Fit the outlet with a second male/female elbow.

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Fitting gutter accessories

Gutter accessories

It's a good idea to fit your guttering with gutter traps or leaf guards to prevent plant debris from blocking up your downpipe and causing your gutters to overflow.

Gutter trap 

gutter trap

Gutter traps are designed to be inserted into the base of the drop outlet in order to catch debris.

Leaf screens and leaf catchers


Leaf screens are designed to be inserted into the gutter to avoid a buildup of debris.

Water butts


Water is a precious resource that should not be wasted. To collect rainwater, you simply need to fit your downpipe with a rain diverter which feeds into a water butt.

No matter what kind of model you go for, water butts are fairly easy to install: you simply need to cut a section out of (or drill into) your downpipe to fit the rainwater diverter. Finally, you just need to connect the rain diverter to your water butt.

Tips for roofs measuring over 12 metres

If your roof is more than 12 metres long, you will need to install outlets at each end of the gutter system to allow the water to drain properly. This involves creating two opposite slopes starting at the centre point of the roof.

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Water butts

How to install plastic guttering

Required skills 


Unlike installing copper or zinc guttering (which requires real skill), you don't need any special expertise to install PVC guttering. You simply need to be able to do the following: take measurements, use a chalk line, use a drill, assemble gutter components (using adhesive or a snap-together system). You should also be comfortable working at a height

Time required 


1 day

Number of people required 


1 person

Tools and equipment 


Personal protective equipment


Please note: this is a non-exhaustive list; be sure to match your personal protective equipment to the job at hand.

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Guide written by:

Sebastian, self-taught DIY-er, Exeter, 192 guides

Sebastian, self-taught DIY-er, Exeter

Redo a roof with wooden beams? Check.Advise Mister everybody in the DIY shop? Check.Redo the bathroom plumbing? Check.Fit together, build the walls, paint a partition, throw my hammer in a rage thinking that it will fix the problem? Check. The DIY motto ? Learning is better than delegating… well, it's also a question about your wallet! The satisfaction? The beer at the end of the job! What do the best have in common? The influence of Gyro Gearloose, Mac Gyver and Carol Smiley depending on your generation, a good dose of curiosity, a average hand-eye coordination and a taste for risks… and if it doesn't work, try again! Advise you? I'll do my best!

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