Construction of the driveway with gravel, crushed stone, and paving

Here is my little experience report:

Also common is 30-40 cm for trafficked paths. You shouldn't go below 30, but over 40 cm usually doesn't make sense if the substructure is okay, meaning natural ground. If it was excavated beforehand, it doesn't matter whether you put 30 or 60 cm on top. If it settles, then the gravel layer above also settles. So this has to be well compacted and ideally it has already been through one winter; after that, it doesn't settle that much anymore. For paving work, it often actually makes sense to do it the following year. Around the house, this is often unproblematic because the working space is always backfilled with suitable material and well compacted. However, the sewer trenches (which are mostly in the driveway area) and the terrace are usually only backfilled with the soil from the excavation pit, and here there can be settlement despite good compaction.

I would definitely use 0/32 basalt gravel, underneath a separation fleece (doesn’t cost much but brings a lot) and then compact the whole thing well, namely with a large vibrating plate or (trench) roller. The DIY store vibrating plates often only compact 20-30 cm. They are good afterward so as not to damage the paving but unsuitable for the substructure.

In the terrace area, I definitely wouldn't go below 20 cm, rather 25-35 cm. The 10 cm are just about 60€ material cost for your area. But as said, a thick gravel layer doesn’t help if the soil underneath settles.

Hi,

In the terrace area, I definitely wouldn’t go below 20 cm, rather 25-35 cm. The 10 cm are just about 60€ material costs for your area. But as I said, a thick layer of gravel doesn’t help if the ground underneath settles.

For a 40 sqm terrace, 10 cm more is a good 4 m^3, so about 7 tons. Where do you get that stuff for 9 euros per ton? At first glance, I find prices more like 18-28 € / ton ??!

Best regards,

Andreas

So we get the 0/32 bulk for 9.30 gross including delivery. I wouldn't skimp on the frost protection... even if it costs twice as much. It's no use if you regret it later because everything has dents after 2 years.

10€ per ton is possible with a short drive. However, it always depends on whether an extra truck is needed for the 4m³ or not. Usually, the civil engineer adjusts it accordingly (they simply apply 28 cm instead of 30 cm to the surface. Moreover, it is generally not excavated that precisely anyway. For excavation pits, +/- 5 cm is normal, or rather the civil engineer should roughly adhere to that. I've also seen many excavation pits where parts were excavated 20-25 cm deeper. For paths, work is usually not done very precisely (often even with a measuring stick instead of a laser level), so with a target height of 35 cm, 30-50 cm of gravel sometimes has to be installed again to achieve a level surface.

But I wouldn't want to save on 5 cm either.

At our place, the civil engineer initially said that 80cm should be replaced. Of course, that was way too much, especially since he replaced 80cm from the base level, whereas we are now easily 25-30cm higher. So we ended up replacing 110cm. Hopefully, the winter of death will come and all those with 40cm replacements will have problems. Then the 3000-4000€ that they took from us due to ignorance at the beginning will have been worth it. I didn’t have any chance to check anything either. They just asked on site, "Should we replace the driveway at the same time?". Eight hours later the hole was already there and the next day filled with gravel. On top of that came a lot of recycled material. Of course, I was a bit pissed off about that, but well, at least the thing holds up every winter now.

Area where 110cm was replaced: 140sqm, so not just a few meters or something.