Problems with poor water run-off? If it sits in puddles next to your walls, soaks your lawn for days or runs towards your house instead of away from it, you have a run-off problem.
It is easy to ignore, but water near your home slowly causes damage you cannot always see. In this guide, we explain how home drainage works, what goes wrong and the steps you can take to fix it.
Why Water Run-Off Matters
Water is heavy, and it always finds the easiest path. When it collects around your house, it can cause problems in five main ways.
It weakens your foundations. Soil holds your home up. When water keeps washing past it, soil is carried away, and the ground under your foundations becomes less stable. Over time, this can lead to sinking, movement and cracks.
It makes the soil swell and shrink. Much of Essex and Suffolk sits on clay. Clay swells when it is wet and shrinks when it dries out. This constant movement pushes and pulls on your foundations, which is a common cause of cracks in walls.
It brings damp and mould. Wet ground next to your walls means moisture can creep inside. This leads to damp patches, musty smells and mould, which is bad for both the building and the people living in it.
It attracts pests. Standing water is a breeding ground for gnats and mosquitoes. Damp, rotting leaves and waste can also draw in rats and other unwanted visitors.
It damages your garden. Waterlogged soil squeezes out air, so roots struggle to breathe and can rot. Heavy rain also washes away topsoil and the goodness plants need to grow.
All of this can also lower the value of your home. Buyers and surveyors look for signs of poor drainage, because they know it can mean costly repairs later on.
Signs You Have a Drainage Problem
Walk around your property during or just after rain. Look out for:
- Puddles that sit next to your walls for hours or days
- Water spilling over the edges of your gutters
- Downpipes that empty straight onto the ground beside the house
- Soil washing away from flower beds or exposing the base of walls
- Damp patches, water stains or mould on inside walls
- New cracks in walls, paths or patios
- Drains that gurgle, smell bad or empty slowly
- Patches of lawn that stay soggy long after the rain has stopped
If you spot more than one of these, it is worth looking at your drainage as a whole.
How Home Drainage Works
Most homes rely on several parts working together. If one part fails, the others have to work harder.
Gutters and downpipes catch rain from your roof and carry it down to the ground or into a drain.
Surface drainage deals with water on top of the ground. This includes channel drains across driveways, gullies and shallow dips in the garden that guide water away.
Subsurface drainage deals with water under the ground. Pipes buried in the soil collect water from wet areas and carry it away.
Slope drainage uses the natural fall of the land, often with pipes laid on a slope, to move water downhill and away from the house.
French drains are trenches filled with gravel and a pipe with holes in it. Water drains into the gravel, enters the pipe and flows to a safe place.
The pipes in these systems are usually made from plastic, PVC or concrete. Plastic and PVC are light and last a long time. Concrete is heavy but very strong, so it suits places that take a lot of weight. Whatever the material, pipes must be laid with a steady downhill fall, usually at least 1 in 100, so water keeps moving instead of sitting still.
Common Causes of Poor Run-Off
Most drainage problems come down to one of these:
- Blocked gutters. Leaves, moss and twigs build up and stop water flowing, so it spills over the sides.
- Short or badly placed downpipes. Water is dumped right next to your walls.
- The ground slopes the wrong way. Instead of running away from the house, rain runs towards it.
- Blocked drains. Leaves, silt and fat can build up inside pipes.
- Damaged pipes. Tree roots and ground movement can crack or crush buried pipes.
- Hard surfaces. Large areas of concrete or paving with no drainage leave rain nowhere to go.
- Heavy clay soil. Clay soaks up water very slowly, so rain sits on the surface.
How to Fix Poor Water Run-Off
1. Find Out What Your Soil Is Like
Every property is different, so start by learning how quickly your ground drains. Try a simple test. Dig a hole about 30cm deep, fill it with water and let it drain. Fill it again and time how long it takes to empty. If water is still there after a few hours, your soil drains poorly.
Clay drains slowly, sandy soil drains fast and loam sits somewhere in between. Knowing your soil type helps you choose the right fix. For a more accurate result, a groundworks contractor can carry out proper testing.
2. Keep Your Gutters and Downpipes Clear
This is the cheapest fix of all. Clean your gutters at least twice a year, in spring and autumn. If you have trees nearby, you may need to do it more often.
Gutter guards help stop leaves getting in while still letting water through. Clearing moss and debris from your roof also stops it washing into the gutters.
Check your downpipes too. They should be fixed firmly to the wall with brackets so they do not sag or come loose. Most importantly, they should not empty right beside your house. Add an extension or connect them to a drain so the water ends up at least 1.5 metres away from your walls.
When you replace downpipes, choose a size that suits your roof and the amount of rain you get. Aluminium is light and does not rust, while plastic is cheap and easy to fit.
3. Get the Ground Sloping the Right Way
The ground around your home should fall away from the walls. A good rule is a drop of about 15cm over the first 3 metres from the house.
To check this, lay a long, straight plank on the ground with one end against the wall. Put a spirit level on top and lift the far end until it is level. Measure the gap between the far end and the ground. If it is less than 15cm, or the ground rises away from the house, it needs regrading.
Once the slope is right, keep it in place. Grass, ground cover plants and mulch all help hold soil together and stop it washing away. On steeper slopes, retaining walls and terraces slow water down and keep soil where it belongs.
4. Install a French Drain
If water still collects in one area, a French drain can help. A trench is dug and lined with a filter fabric. A pipe with holes in it is laid on a bed of gravel, then covered with more gravel and wrapped in the fabric.
The fabric matters. It lets water in but keeps soil out, so the drain does not clog. The gravel should be large enough to let water pass freely. The pipe must also fall steadily from where the water gathers to where it can safely drain away.
French drains take careful planning, so it is worth getting expert advice on the depth, size and route.
5. Deal With Hard Surfaces
Driveways and patios cover ground that would otherwise soak up rain. If yours sends water towards the house, a channel drain across the front can catch it.
When you replace a driveway, think about permeable options such as resin bound surfacing or permeable block paving. These let water drain through rather than run off. In England, paving more than five square metres of a front garden with a surface that does not let water through usually needs planning permission. You can read more in the Planning Portal guidance on paving your front garden.
6. Protect Cellars and Lower Floors
If your home has a cellar or sits low on its plot, you may need extra protection. This is especially true where the water table is high. A sump pump collects water in a pit and pumps it away before it can build up. Waterproof membranes on outside walls add another layer of defence.
7. Try Greener Options
There are simple ways to manage rain that are kind to the environment too:
- Water butts collect rain from your downpipes so you can use it in the garden. Make sure the overflow is directed away from the house.
- Rain gardens are low planted areas that soak up run-off.
- Gravel trenches are an easy, low-cost way to guide water away and reduce soil loss.
Keep Your Drainage Working
Good drainage needs looking after. Check your system at least once a year and after any big storm. Look for blockages, cracked pipes and areas where the ground has sunk, or the slope has worn away.
Keep plants under control too. Avoid planting thirsty, deep-rooted trees close to your house or drains, as their roots can break into pipes. Drain guards over gullies help stop leaves and silt getting in.
Heavy downpours are becoming more common in the UK, so it pays to make sure your drainage can cope. The government’s advice on how to prepare for flooding is a useful place to start.
Frequently Asked Questions
Can poor drainage affect my neighbours?
Yes. You are responsible for the water that runs off your property. If your drainage sends water onto a neighbour’s land and damages it, this can lead to disputes and even legal costs.
How do I know if my drainage meets the rules?
New drains must follow building regulations. For larger jobs, or if you are unsure, a qualified contractor can inspect your system and check it is up to standard.
Can landscaping help with drainage?
Yes. The slope of your garden, the plants you choose and the surfaces you lay all affect where water goes. Good landscaping works with your drainage rather than against it.
How often should drainage be checked?
At least once a year. Gutters need clearing twice a year, more often if you have trees close by.
Get Expert Help With Your Drainage
Some fixes, such as clearing gutters, are easy to do yourself. Others, such as regrading a garden, laying a French drain or replacing a damaged pipe, need the right skills and equipment.
At L Groundworks, our team handles drainage work in Colchester and across Essex and Suffolk. We can find the cause of your run-off problem and recommend the right fix. We also offer landscaping, resin driveways and foundation work, so we can fix the problem and the ground around it in one go.
If water is building up around your home, get in touch with our team for a free quote.