Definitely encourage your friend (or help him?) to clear out every single weed . . . easy at this stage when you can see them clearly. If some are left, and your friend is truly an 'amateur' then when plenty of things are growing, he might be unable to distinguish between a genuine plant and a weed?!

His daughter will then have a pristine patch to enjoy gardening.

I think, too, he needs to level it or he might find he has less topsoil to spread than he thiks.

Oh, I'll help him alright, he once bought a large mill and I built him a suite of offices inside, him mixing mortar and me laying blocks, all in 5 weekends.
Thanks for the info, I'll pass it onto him. Is there anything else we should do prior to spreading the topsoil ?

After weeding and leveling and before the topsoil addition I then he should sprinkle on weed preventer. Then after the topsoil has been applied sprinkle the same over that layer.

Thanks L, wll pass that on too. More ?

Weed preventer? As far as I'm aware, that type of product is not available in the UK, pre emergents here are only for agricultural/professional sports use, Loosestrife and not available to amateur gardeners, unlike in the USA.

I'd confirm he does need to remove all weeds, by the roots, before the topsoil goes on. Bear in mind though, unless he's bought top quality topsoil, most of what gets delivered these days is motorway spoil with the biggest rocks removed, so it'll come with its own crop of weed seeds, which will grow over the next few months, so regular hoeing will be a necessity - even so, its still best to get out anything that's already there. If its going to be planted later on, I'd also suggest he turns the soil over before the topsoil comes in, and he should add some composted manure in with the topsoil, probably around 4 bags worth as a minimum, to up the fertility.

Hi Hank, I agree with all the above, I have tried for tears to get hold of some casaron g, weed preventer without success, Derek.

Is corn gluten meal available in the UK, Bamboo? It is shorter acting than the chemicals, but it might still be helpful.
Just a note on weed preventers: they are most effective when applied after all planting is done, and non-living ground covers are applied. Any digging done after the weed preventer is applied will "break the barrier", and allow weeds to sprout. Also, most weed preventers stop weed seeds from sprouting successfully, but will not stop weeds growing from underground roots.

Not easily, Tug - if it is sold here, its sold as a feed for livestock. Plus I found this somewhat interesting article about lookalike products which won't do the same job. I've never used any kind of pre emergent, organic or chemical, always relied on the old fashioned dig it out and dig it over, then just hoe and add composted materials year on year... but then, gardens here, generally, are so much smaller than many in the States

https://lawnsavers.com/blog/will-the-real-corn-gluten-please-stand-up/

I'm using preemergents because I must now enter into methods used in the garden to lessen the work load and make things as easy for myself as possible. The time has come to morph my garden from a cottage one to a geriatric one.

Raised beds, a lot more paving and lots of geotextile membrane then, Loosestrife;-))) Or move...

Move? You're a mind reader Bamboo:) Looks like this Victorian of mine will become a Bed and Breakfast in the not to distant future.

Not really a mind reader - comes to all of us in the end, if we live long enough, needing to downsize... so long as the downsize isn't something that measures roughly 6 x 3 feet, I reckon we're doing alright!

LoL! In the end I'll be weed feed. In that case, no pre emergents or herbicides will be used.

I'm expecting to be ash, blowing in the breeze, eventually, though hopefully not yet a while...;-))

I always said I wanted a rowan tree planted on my grave so that the birds would have something to eat. Then I realised they'd also poo......

Well, you probably wouldn't notice, Arbuthnot! What I actually want is something called promission - freezing in nitrous oxide, then shattering into bits. No burning, no Co2 emissions, but its not available here yet... Still, its a ways off yet...

Most likely N2O will never be made available to the public aside from being a propellant in whipped cream cans. Too much potential for abuse(substance type)

Ah, well, wasn't thinking of doing it at home, Loosestrife, lol! No, there was some talk of crematoriums changing over to the N20 system because of new legislation tightening up on emissions, which would mean the crems needed to invest thousands to get their emission reductions down. Just as cheap to switch to N20 instead...

Well, N2O is in the category of a greenhouse gas pollutant so that would be a poor choice for turning a former human being into an Ice Popsicle so it can be hit with a cricket bat and smashed to pieces. A better cryogenic fluid would be plain liquid nitrogen I think.

Ah, okay, that's probably what I mean then, lol! Its so long since I read about it, and I'm no chemist, find all that difficult to get a handle on and remember, so I probably said nitrous oxide when I meant liquid nitrogen - whatever they used in The Terminator, I think;-))

My friend had gis load of topsoil delivered, spread it, and now needs another load ! As someone said he would.

Arb don't you know that a bird bombing your head means good luck.... but then again..... if your six feet under?