Installing New Gutters

From Australian Handyman Magazine

Fix or replace guttering to prevent leaks and damage.
Gutters and downpipes prevent water damage to walls and foundations. Since they’re out of reach, maintenance and repair is often neglected. Damage may be minor and easily repaired, often with a squirt of silicone. If damage is extensive, install a new gutter system.

Download Installing New Gutters project PDF

Styles range from the traditional quad gutters with external brackets that adorn Federation homes, to modern square and half-round styles fixed to steel fascia with suspension clips. Whatever style it is, the guttering should blend in with the house, usually in a colour matching the roof and fascia.

Type of system depends on the flow rate required to cope with the volume of water run-off that spills from the roof. Big roofs need bigger gutters and downpipes.

DIY products, advice and tools come from suppliers, but check with the council if DIY is permitted – some areas require gutter installation to be done by professionals

STEP 1

Assemble the Guttering
1. Cut gutter to length for each fascia run using tin snips or a hacksaw. Overlap joins by minimum 100mm in the direction of the flow, then pre-drill.
2. Run beads of roof and gutter silicone across the base and up the sides of the overlap. Reposition the gutter upside down, overlapping the pre-drilled holes, and join together with 3.2mm-diameter rivets. Seal around the rivets and along the seam with silicone, smoothing so that water flow is not impeded.

STEP 2

Attach Stop-Ends
1. Position stop-ends and pre-drill for riveting with two holes up the back, two across the base and one or two up the face side.
2. Run a bead of roof and gutter silicone along the overlap. Position the stop-end, fix securely using 2mm rivets then dab silicone on rivets.
TIP: There are left and right stop-ends.

STEP 3

Assemble the Spout
1. Downpipe spouts must align with stormwater pipes. Mark the centre of the outlet on the bottom of the gutter. Place the spout, flange side down, and trace the inside. Put timber off-cuts under the hole and cut a V-shaped notch with a cold chisel. Cut 1-2mm outside the lines using tin snips.
TIP: Red snips cut counter-clockwise, green snips cut clockwise.
2. Slip the spout into the outlet hole and pre-drill two 2mm holes on short sides of the flange for rivets. Remove the spout and run a bead of silicone around the opening. Press the spout into the silicone and fix with rivets.

STEP 4

Prepare the Mitre
1. Measure and mark up the mitred corners. For internal mitres, the face sides are shorter than the back. For external mitres, the face sides are longer than the back. Measure the width of the gutter and transfer this measurement along the back or face top edge. Mark this point and draw a 45º line to the opposing corner. Allow 5mm length for the bracket.
2. Test-fit the mitre in the corner bracket. Run a bead of silicone along the bottom edge of the gutter and the top edge of the lower bracket only. Temporarily clamp and tighten the internal bracket in place.
TIP: Don’t glue the top internal part of the bracket until the second half of the mitre has been positioned.

STEP 5

Hang the Gutter
1. To set the slope, drive a nail 10mm below the top edge of the fascia at the high end. Calculate minimum gutter fall of 1:500 (AS2180-1986) for 2mm of fall for each metre of gutter. Drive a nail at the lower end. Fix a stringline between nails and check fall with a spirit level.
TIP: If fall isn’t steep enough, water pools in the guttering.
2. Position brackets along stringline at maximum 1200mm centres. Fix with twist galvanised gutter nails.
3. Get help to lift gutter runs. With external brackets, roll the tip of the bracket strap over the top rolled edge and fix the back top edge of the gutter to the fascia with 40mm galvanised gutter twist nails.

STEP 6

Add Downpipes
1. Houses with eaves require a downpipe offset to return the downpipe to the wall. They can be bought with a slip joint or make your own (see Diagram 2). Prepare the lower offset first and position against the wall to align with the upper offset.
TIP: The downpipe face is cut with this joint.
2. Use a plumb line from the outer edge of the spout down the side of the downpipe and mark. This lower point is the centre point of the upper offset cut (see Diagram 3).
TIP: The downpipe seam at the back is cut with this joint.
3. A second length of downpipe is used to connect the downpipe to the stormwater at 45º. Measure the length needed to bring the downpipe inside the stormwater and mark this around the downpipe. To set 45º on the face, draw a line half the width of the downpipe on either side of the first line and cut out as far as the lower offset (Diagram 4).
4. Slide the bottom half of the downpipe inside the upper section. Position for a snug fit between the gutter and stormwater. Rivet downpipe sections together at the back, then rivet the downpipe to the spout. Anchor the downpipe to the wall with two brackets (astragals) and masonry anchors.