Ask every quote for a depth

How deep is the sub-base, and what is the total excavation depth. That is it. A quote that answers in numbers and a quote that answers in adjectives are not the same document, whatever the totals say.

Here is why it matters. A hundred millimetres of compacted Type 1 under a twenty square metre drive is about two tonnes more stone than seventy five millimetres, plus the muck-away for the extra dig, plus the machine time. On a small drive that difference is several hundred pounds, and it is completely invisible the day the job finishes.

So a firm that wants to be the cheapest quote on your kitchen table has an obvious place to find the money, and it is a place you cannot check and will not notice for two years. We are not suggesting anybody does this dishonestly. Plenty of people in this trade simply build the way they were taught by someone who also did not measure.

What the depth should be depends on what stands on it and what is under it. A car on sand or gravel wants a hundred. Clay adds fifty and a membrane. A van wants a hundred and fifty. A caravan or a horsebox wants two hundred and upward.

You do not need to know which applies to you. You need the number written down, on every quote, so that you are comparing the same job. If one of them will not put it in writing, you have learned something more useful than a price.