Dig out the trench about 6 inches deep along the line, using a slope gauge to slope it 1/4 inch per foot. Dig a dry well about two to four feet wide and three feet deep at the low end of the trench. Line the trench with landscape fabric and gravel. Then lay in 4-inch perforated drainpipe with the holes facing down.
A paver patio is built on granular material that drains quite well. so there is no need for a drain under it. Even if the material under it becomes saturated, the patio surface will still shed water, and eventually the saturated material will still drain.
Slope the pavers an 1/8 bubble towards your desired drainage area. Fill the joints with polymeric sand. Pavers are porous so they will absorb some moisture but heavy rain will sheet off of them and the poly sand.
In most cases, we would recommend that you install a soakaway crate, in order to let the water seep away naturally into the ground.
If your backyard doesn't have a natural slope, you can install a filter fabric or geotextile as they are commonly called. They are made of a permeable material that prevents the subgrade from moving while allowing water to drain. By installing this underneath your pavers, you could extend the lifespan of your patio.
Dig out the trench about 6 inches deep along the line, using a slope gauge to slope it 1/4 inch per foot. Dig a dry well about two to four feet wide and three feet deep at the low end of the trench. Line the trench with landscape fabric and gravel. Then lay in 4-inch perforated drainpipe with the holes facing down.
If the existing concrete patio lacks a drainage system, it is a practical move to install one. In areas where the rainwater collects, cut a sloping channel. A well-cut channel directs the water away from the patio. Fill the channel with decorative stones or gravel so it meets aesthetic ideals.
A concrete patio drainage channel like Slot Drain is the ideal way to protect your outdoor recreation area from the damaging effects of water. The most efficient option available, Slot Drain is a sleek, easy-to-install option that will easily handle any water runoff from your patio area.
Patios must have a slight slope (1" for every 4' to 8') for proper drainage. If you don't provide enough slope, rainwater will settle into low spots, eventually softening and washing out the sand and subbase materials beneath.
Paver sand, however, fills gaps and creates a smooth surface, helping to secure the pavers and improve drainage.
Preparing the base
To lay a solid base for your paving slabs, you first need a layer of hardcore at a depth of about 50mm to 80mm over the area of your patio. Use a rake to distribute the hardcore, evening out any bumps, then add a layer of bedding mortar over the compacted hardcore.
Pea gravel is one of the best materials for landscape drainage because its small size allows for outstanding drainage. These rocks are only about ¾ inches in size. Pea gravel is available in a variety of shades, including brown, grey, blue, and red, making it a good choice for a number of different landscapes.
However before you lay down any paving slabs, you should consider a patio drainage system. By ensuring the removal of standing water from a patio (which can happen as a result of heavy rainfall) a properly installed drainage system can help you to avoid bacteria growth and even insect infestations.
Often, sand is used with crushed stone to gain more durability. Concrete sand is a popular option since it's coarse and won't trap excess moisture under the paver surface. Crushed stone by itself is a common paver base. It's a solid option and provides good drainage.
A channel drain is a linear drainage solution designed to remove large quantities of water from a patio, or any paved, tarmac, or concrete area. It is essentially a long, narrow channel integrated into the hard landscaping covered with a removable grate, to collect and channel water away from the area.
Water erosion is one of the most common reasons for a patio to sink or dip over time. Below all of the foundation gravel and sand is all-natural soil. This soil can be affected by water erosion causing a dip in your patio.
If your patio used to drain well after a heavy rain, but now seems to collect water, you may have a clogged drainage system. Over time debris can collect in the drainage channels and cause a blockage.
Standing water can seep into the ground, eroding the soil beneath the pavers and causing them to shift or sink. A poorly drained base can become soft and unstable, leading to uneven pavers and cracks. Freeze-thaw cycles can cause water trapped under pavers to expand, leading to cracks and dislodged pavers over time.
Soakaways work well for patio drainage and driveways, where the water table or saturation line (the upper level of groundwater that is naturally held within the soil, sub-soil, or bedrock) is of a lesser volume.