The complete guide
How To Choose And Fit A Round Leaf Cover For An Outdoor Gully
The puddle that comes back every autumn
Most Irish houses have at least one gully outside. It might sit under the kitchen window, where the sink waste comes out. It might be at the foot of a downpipe, taking rain from the gutter. Often it is a round or square pot set into the ground with a grid on top.
That grid matters more than it looks. Take it away, or let it crack and go missing, and the gully becomes an open hole. Leaves blow into it. Moss slides off the roof and down the pipe. Gravel from the path gets kicked in. Children drop things in it.
Everything that falls in settles at the bottom, in the trap. A gully trap holds water for the same reason the bend under your sink does. It stops smells coming back up. But a trap full of rotting leaves cannot pass water, and the first you know of it is a grey puddle spreading across the yard on a wet night.
A cover does not fix a blocked drain. What it does is stop the blockage being built in the first place.
What this cover is
This is a round drain cover, sold as 175mm across. It is made of plastic, it is black, and the maker gives its weight as 60 g. One cover comes in the pack.
The surface is a round grid pattern. The maker says the pattern lets water flow through while holding back leaves and debris. That is the whole job of a leaf cover. Water goes down, leaves stay on top, and you sweep the leaves away.
The maker describes the finish as painted and the look as modern. In plain terms it is a simple black disc that will not draw the eye in a patio or a gravel yard.
What we do not know
It is better to be direct about the gaps than to guess.
The maker gives no thickness. The size of the openings in the grid is not stated. There is no list of gully makes or models it suits, and the fixing method is not described beyond a general statement that setup is simple.
The most important gap is strength. The maker does not state that this cover is made for foot traffic or for vehicle traffic. The maker's description does mention driveways as a place it might be used, but mentioning a place is not the same as stating that a cover can carry a car.
So we sell it as a leaf guard, not as a load-bearing cover. Fit it over a gully in a flower bed, beside a wall or in a corner of the yard where nobody walks. Do not fit it in the middle of a path, and do not fit it anywhere a wheel will cross. A drain in the way of feet or vehicles needs a cover that is made and rated for that load.
At 60 g this is a light part, which fits with that advice.
Measuring before you buy
The single figure to work from is 175mm.
If you have the old cover, measure straight across it at the widest point. Turn it a quarter and measure again. Old plastic covers warp and old gullies are not always perfectly round, so two readings are better than one.
If the old cover is gone, measure the recess it sat in. That is the ledge inside the top of the gully. Measure across the ledge from inner wall to inner wall. A cover that is a few millimetres too big will not drop in. One that is too small will fall through or rattle about.
Also look at depth. If the recess is shallow, a thick cover will stand proud and catch a foot or a brush. The thickness of this cover is not stated by the maker, so the product photos are your guide.
Check whether a pipe discharges into the gully from above. Some gullies have a downpipe shoe or a waste pipe ending just over the grid. The water needs to land on the grid and run through. The maker does not state that there is a cut-out for a pipe.
If your gully is square, or a different size, this is not the right cover. Forcing or trimming a plastic grid tends to end with a broken grid.
Clear the gully first
There is little sense in putting a clean cover over a full gully.
Put on waterproof gloves that reach up your forearm. Lift out whatever remains of the old cover. Scoop the leaves and silt out by hand or with an old trowel, and put it in a bucket for the brown bin or the compost heap, not back onto the yard.
Reach down into the trap if you can and clear that too. Then pour in a bucket of clean water. It should drop steadily and run away. If it does, the gully is clear and you can fit the new cover.
If the water sits there or drains very slowly, the blockage is past the trap, further along the pipe. A cover will not help with that. On your own property it is a job for a drainage contractor with rods or a jetter. If the trouble is in a public sewer, contact Uisce Éireann or your local authority.
We do not recommend chemical drain cleaners for gullies or for any other drain. Clearing by hand and flushing with water is safer for you and does the job.
Fitting and the limits of the job
Putting a loose cover onto an existing gully is a household task. Sit it in the recess, check it lies flat and does not rock, and pour a little water over it to see that it runs through.
Changing the gully itself is another matter. Digging out a broken gully pot, connecting a new one or moving a drain is fixed drainage work. That should be done by a qualified person, and the Irish Building Regulations apply to it. A new cover is a quick fix for a missing grid. It is not a repair for a cracked gully.
Keeping it working
A leaf cover only works if somebody clears it. Left alone through October and November, the leaves mat together on top and the water has nowhere to go. You end up with the same puddle as before, only this time the blockage is at the surface.
That is still the better outcome. A mat of leaves on top of a grid takes ten seconds to lift off. The same leaves packed into a trap take half an hour and a pair of long gloves.
Get into the habit of brushing the cover off when you sweep the yard. After a storm, have a look. Once or twice a year, lift the cover out, rinse it and check underneath. An old washing-up brush clears moss from the openings.
While it is out, look it over. Outdoor plastic lives a hard life between frost, sun and the odd knock from a wheelie bin. The maker describes the cover as made for outdoor conditions but gives no figures, so an annual check for cracks is sensible. Replace it if it has split.
Other ways to keep leaves out of drains
A gully cover is one part of the picture. If the gully takes a downpipe, much of what arrives in it started in the gutter. Clearing the gutters once the trees are bare cuts the load a great deal. A guard at the top of the downpipe helps too.
Around the gully, keep gravel and bark mulch back from the edge. Both wash in during heavy rain. And if a kitchen waste discharges into the gully, the grease from it will collect on the grid over time, so that one will need a wash with hot water and washing-up liquid now and then.
The short version
An open gully fills with leaves, and a full gully floods the yard. A grid on top stops most of it at the surface.
This is a round drain cover sold as 175mm across, in black plastic, weighing 60 g. The round grid pattern lets water through and holds leaves back. Thickness, opening size and fixing method are not stated by the maker, so measure your gully and check the photos.
The maker does not state that it is made for foot or vehicle traffic. Treat it as a leaf guard and keep it out of the way of feet and wheels. Clear the gully before you fit it, sweep the cover when you sweep the yard, and call a drainage contractor if a clear gully still will not drain.