ᐅ Construction of a driveway using gravel, crushed stone, and paving stones?

Here is my brief experience report: https://www.hausbau-forum.de/threads/pflaster-und-platten-von-rinn.14699/#post-125407

It is common to use 30-40 cm (12-16 inches) for driveways. You should not go below 30 cm (12 inches), but usually, more than 40 cm (16 inches) doesn’t make much sense if the subsoil is stable, meaning natural ground. If the area was previously excavated, it doesn’t matter whether you use 30 or 60 cm (12 or 24 inches) of material on top. If the ground settles, the gravel layer above will settle as well. Therefore, it must be well compacted and ideally left to settle over the winter; after that, there will be less further settlement. For paving work, it often makes sense to do it the following year. Around the house, this is usually not an issue, as the working space is always refilled with appropriate material and well compacted. However, drainage trenches (which are usually located in the driveway area) and terraces are often only refilled with excavated soil from the construction pit, and settlement can occur despite good compaction.

I would definitely use 0/32 basalt gravel, with a separation geotextile underneath (which is inexpensive but very effective), and then compact the entire layer thoroughly, preferably with a large vibrating plate or a trench roller. The smaller vibratory plates available at hardware stores typically only compact to 20-30 cm (8-12 inches). These are good for later compaction to avoid damaging the paving but are unsuitable for the base layer.

For terraces, I would never go below 20 cm (8 inches), preferably 25-35 cm (10-14 inches). The 10 cm (4 inches) difference only costs about €60 in materials for your area. But as mentioned, a thicker gravel layer won’t help if the soil underneath is settling.

Hi,

86bibo schrieb:


For the terrace area, I definitely wouldn’t go below 20 cm (8 inches), preferably 25-35 cm (10-14 inches). The 10 cm (4 inches) difference only costs about €60 in materials for your area. But as mentioned, a thick layer of gravel doesn't help if the soil underneath settles.

For a 40 m² (430 ft²) terrace, an extra 10 cm (4 inches) means over 4 m³ (140 ft³), which is about 7 tons. Where do you get that material for €9 per ton? At first glance, I’m seeing prices around €18-28 per ton instead.

Best regards,

Andreas

So, we are getting the 0/32 aggregate here for 9.30 gross, including delivery.
I wouldn’t save money on the frost protection... even if it costs twice as much.
It’s no benefit if you regret it later because everything is dented after 2 years.

10 euros per ton is possible with a short transport distance. However, it also depends on whether an extra truck is needed for the 4m³ (5.2 cubic yards) or not. Usually, the civil engineer adjusts accordingly (applying only 28 cm (11 inches) instead of 30 cm (12 inches) on the surface). Additionally, excavation is generally not that precise. For the foundation pit, a tolerance of +/- 5 cm (2 inches) is normal and should be roughly maintained by the civil engineer. I have also seen many foundation pits where parts were excavated 20-25 cm (8-10 inches) deeper. During weighing, work is generally not extremely precise (often using a measuring tape instead of a laser level), so with a target height of 35 cm (14 inches), sometimes 30-50 cm (12-20 inches) of gravel has to be added to achieve a level surface.

However, I would not want to save on 5 cm (2 inches).

At the beginning, the excavation contractor told us that 80cm (31.5 inches) needed to be replaced. That was obviously way too much, especially since he replaced 80cm (31.5 inches) measured from the original ground level, and we are now easily 25-30cm (10-12 inches) higher than that. So in the end, 110cm (43 inches) were replaced. Hopefully, we'll have a harsh winter soon, and all the areas with just 40cm (16 inches) will have problems. Then the 3,000-4,000€ that we were charged initially due to lack of knowledge will have been worth it. I had no chance to check anything at the time. The only question on site was, “Shall we replace the driveway as well?” Eight hours later, the hole was already dug and filled with gravel the next day. On top of that, a large amount of recycled material was used. I was, of course, a bit annoyed by that, but well, now at least the whole thing will hold up every winter.

The area where 110cm (43 inches) was replaced measures 140sqm (1,507 sqft), so it’s not just a few meters or anything small.