- Compacted gravel driveway: the conditions for success
- Two layers of aggregates
- The right materials for a driveway
- Delimit with precision
- A muscular construction site
In order to gain access to his garage under construction and to improve the surroundings of his house, Didier Martinaud has created a stabilized floor worthy of a public works professional. Example to follow!
Time: 4 to 5 days
Cost: 1 400 Euros (for 150 m2)
Equipment: earthmoving equipment, compactor roller 650 kg (rental 95 Euros per day)
Supplies: gravel, geotextile felt, concrete border (50 x 20 x 5 cm).
See the plan of this realization (in pdf): Garage driveway: the plan
Too often, making a gravel driveway is a wait-and-see solution or an economic stopgap.
At the beginning temporary, the gravure continues however and, as it was carried out quickly, the inconveniences do not take long to appear. Nature takes back its rights: the weeds point, the earth goes up, the ruts widen...
If you want to create a driveway, do not just spread a few wheelbarrows of gravel packed with a grass roller. for a price barely higher, you can have a stable, durable and easy to maintain.
Like Didier Martinaud, follow all the requirements imposed by the technical regulations for the realization of a "low-paved unpaved road".
Compacted gravel driveway: the conditions for success
The first rule is to delimit precisely the border between the grass and the alley. With a trench 30 cm deep, filled with a concrete sole on which are sealed edges (stone or concrete), the problem is solved: the grass will not pass over or the roots underneath.
The second condition is the thickness of the layer.
Here, the first bed measures 20 cm and the second bed 10 cm. It is therefore necessary to remove 30 cm of soil thickness over an area of 150 m2, ie a volume of 45 m3. Which corresponds to a little more than sixty tons of earth.
The following is easier.
The bottom of the excavation is lined with a polypropylene geotextile felt (type Bidim Green). It prevents upwellings, stabilizes the soil and delays the passage of roots.
Two layers of aggregates
The two layers of aggregates that fill the excavation fulfill different functions.
The first, the thickest, ensures the shape and stability of the whole. It has a relatively coarse grain size, 0 to 31.5 mm in diameter. It is usually a mix of crushed material that rolls well. Attention, it is indeed a compactor roller or, failing that, a vibrating plate, not a simple grass roller!
The use of this machine is essential for the durability of the coating. The more it is packed, the slower the ruts will appear. The rental networks of construction equipment (Loxam, Kiloutou...) offer this type of machine. Ask about the delivery terms.
The second layer ensures the drainage of surface water and the appearance of the driveway. Living in Beaujolais, Didier Martinaud has obtained a beautiful ocher / red coating. Choose a finer aggregate (0/14 mm) than the primer. The appearance will be more regular. This layer is compacted like the previous one.
The right materials for a driveway
The classification of aggregates is complex because it takes into account many parameters.
Unless you are close to our reader, you will not find the same variety of aggregate because it depends mainly on the production site.
When you are looking for suppliers in your area (quarries and trade in professional materials), ask for the standard designation NF EN 13285 of "Graves Untreated" (GNT or roadside) of caliber 0 / 31.5 mm (GNT 2 ) and 0/14 mm (GNT 4).
Then let them know what exactly it is, since it can be a career granulate like a demolition product recycling.
The origin influences the price, the ordered volume and the delivery distance.
Delimit with precision
Borders materialize the limits of the aisle. They are sealed in a concrete trench about 30 cm deep. The string is set to pass 2 cm above the finished floor.
The search is disbursed on a spade depth (about 30 cm). Stakes approximately adjust the level. There is no slope to predict since the coating drains the rain.
The bottom of the excavation is equalized to the rake and then lined with a synthetic felt. The overlap between the strips is about 30 cm. A few shovels of rubble keep them flat on the ground.
A muscular construction site
A layer for stability. the truck empties its load at the entrance of the property. It takes several tens of wheelbarrow trips to spread the aggregates, 20 cm.
The compactor roller is rented. Weighing 650 kg, it is fortunately self-propelled! It takes five or six passages in all directions, paying attention to the edges to properly compact.
A layer for finishing. More regular, it measures only 10 cm thick. Spread and equalized before being generously watered and rolled, it is flush with the level of the borders.
The color of the coating will be different depending on the region of the production site. By choosing a fine aggregate, you will get a regular appearance after a new compaction.
For a more natural look after compaction, spread with a shovel, a thin layer extra to equalize then to the rake held upside down, the teeth turned to the sky.