garden Topsoil or no topsoil, that is the question

[Ebrin_devon]

Good morning all,

 

Thank you for allowing me to take part in this forum. Just to introduce myself, my name is Eric and I'm a newbuild homeowner. The reason why I am writing on this forum is to seek guidance from other more knowledgeable users in regards to landscaping.

 

I am based in East Devon, in an area which is predominantly very clayey. The land where my development was constructed used to be farmland, and so I assume that it is quite fertile. Anyhow, I think I'll just start off describing my concerns in chronological order:

 

1. At reservation stage, the developer provided us with a standard specification setting out finishes, colours, etc. One of the items in the spec was the finish to the garden areas (back garden and a strip out front along the facade). The spec stated that the ground would be finished with a 150mm thick layer of topsoil. I was quite glad that this was the case, as my concern was that the underlying clay would challenge the garden's ability to drain rainwater.
2. Fast forward to completion, we get the keys to the house and to my surprise, the garden was topped off with site-won material, i.e. clay. In addition, the plot was plagued with stones the size of fist. To me that didn't look like topsoil... However, the next question I asked myself was: what is topsoil anyway?
3. Doing some research, I found that there is a British Standard entitled "Specification for topsoil" (BS 3882:2015 - in case you're interested). This standard sets out the requirements for a soil to be classified as topsoil. One of these requirements is that the "maximum coarse fragment content" greater than 50mm has to be 0%. In other words, stones greater than 50mm in diameter should not be present at all, which is something that my garden clearly doesn't meet.
4. I have gone back to the developer with this (it's been more than a month already) and they are still figuring out what to respond. I am not trying to be picky here, but I've paid a large sum of money for my new home and I will  always try to make sure that I obtain a quality product that meets the minimum standards. I should add that the NHBC standards specify that gardens should be finished with a minimum of 100mm of topsoil.
5. NB: my neighbours have placed a ver thin film of topsoil on their garden after picking out the majority of big stones. They then planted some grass seed and it's growing well. However, I think as soon as they start transiting the grass, the clay will compact and it'll become boggy with rain, which will eventually compromise the health of the grass, etc.

 

I would be grateful if others could share their views/experiences on the matter, as I'm not sure if I'm making this a bigger issue than what it really is?

 

Thank you very much,

 

Eric

[joe90]

Welcome to Devon, yes I am on clay and it can be very difficult, no drainage. I “bought” 20 tons of topsoil from a local farmer and it was awful, very clayey. I bought another 40 tons from a landscape gardener who guaranteed it was slightly Sandy and this was a lot better. Stick to your guns, get the seller to provide what was in the “contract”. My nephew bought a new house on an estate and the first time it rained their garden flooded, they made the contractor instal land drains to rectify.

[Ralph]

Second what @joe90 writes. We are on clay and it's a pain to deal with when it rains. Getting rid of stones and improving soil takes a lot of work so do try and keep the pressure on the developer to sort it out.

 

You may also find all sorts of things buried rather than taken off site. 

[Mr Punter]

I have worked on sites where if you are planting trees in the winter the hole you have just dug will fill with water before the tree is staked.

 

Make sure you have paving where you are going to walk or you will end up with an unsightly track over your new lawn.

 

As above, 150mm topsoil is what you paid for.

[Thedreamer]

On individual self builds, the usual practise would be to scrap the top soil and keep it to one side for landscaping. But on a developer site who knows where the original top soil went.

 

How much garden ground are we talking, if it's a small developer garden maybe just a three or four bulk bags from the building merchant would do the job.

 

 

 

 

[saveasteading]

If the developer is one of the big companies, there is always resistance. One of the barriers is that they forget that they do not consider themselves contractors and try to blame someone down the line.

In reality, their methods are usually to take all the soil off site and dump it. Then later they try to cover with as little real soil as they can get away with.

 

Perhaps someone on here who has argued with developers before can point you in the most efficient direction.

Letter to the CEO never does any harm.

A story in the local press can work as it affects the perception of quality.

 

Cynically, they will often offer a solution to one complainant on condition that they don't tell anyone else. 

[Ebrin_devon]

Gents, thank you very much for your prompt responses.

 

3 hours ago, joe90 said:

Welcome to Devon, yes I am on clay and it can be very difficult, no drainage. I “bought” 20 tons of topsoil from a local farmer and it was awful, very clayey. I bought another 40 tons from a landscape gardener who guaranteed it was slightly Sandy and this was a lot better. Stick to your guns, get the seller to provide what was in the “contract”. My nephew bought a new house on an estate and the first time it rained their garden flooded, they made the contractor instal land drains to rectify.

Thanks @joe90. I'd have to read in detail what the British Standard says about the clay content and the drainage capacity of the soil, but it could be that the first batch you "bought" from the local farmer may not have been something that met the BS requirements? The fact that the soil is located on the top stratum does not mean it can be classed as "topsoil". At least that is my interpretation of this very confusing topic. Thankfully we haven't had any flooding, but puddles do form here and there, so it's not great.

 

3 hours ago, Ralph said:

Second what @joe90 writes. We are on clay and it's a pain to deal with when it rains. Getting rid of stones and improving soil takes a lot of work so do try and keep the pressure on the developer to sort it out.

 

You may also find all sorts of things buried rather than taken off site. 

Thanks @Ralph. Agreed, not great being on clay! I wouldn't be surprised if we found random stuff buried in the ground...

 

3 hours ago, Mr Punter said:

I have worked on sites where if you are planting trees in the winter the hole you have just dug will fill with water before the tree is staked.

 

Make sure you have paving where you are going to walk or you will end up with an unsightly track over your new lawn.

 

As above, 150mm topsoil is what you paid for.

 Thanks @Mr Punter. Good point about the paving. We'll certainly have that done eventually. However, we're thinking of getting a puppy sometime soon, and I can already see myself running around the lawn. Regardless, provided the top layer is not comprised of very fine particles, i.e. clay, this shouldn't compromise the ground's ability to drain?

 

2 hours ago, Thedreamer said:

On individual self builds, the usual practise would be to scrap the top soil and keep it to one side for landscaping. But on a developer site who knows where the original top soil went.

 

How much garden ground are we talking, if it's a small developer garden maybe just a three or four bulk bags from the building merchant would do the job.

 

Thanks @Thedreamer. I am pretty certain the material was site-won from the excavations of the foundations and general earthworks on the actual development. Interestingly, the garden was originally meant to be two-tiered, but what we found is a completely level garden. We prefer it being level for obvious reasons, but I'm sure this was done to take advantage of the amount of excavated material. The fact is that I wouldn't mind if they used site-won material... My concern is that such material is not compliant with the aforementioned British Standard.

 

Garden is roughly 90 sq. m, so I reckon 20t would be needed for a thickness of 150mm. However, we also need to factor in the excavation of the material currently in place, which is no small task! Don't know how the contractor would do it due to the fact that the garden is completely fenced off (can't bring in a digger).

[Ebrin_devon]

7 minutes ago, saveasteading said:

If the developer is one of the big companies, there is always resistance. One of the barriers is that they forget that they do not consider themselves contractors and try to blame someone down the line.

In reality, their methods are usually to take all the soil off site and dump it. Then later they try to cover with as little real soil as they can get away with.

 

Perhaps someone on here who has argued with developers before can point you in the most efficient direction.

Letter to the CEO never does any harm.

A story in the local press can work as it affects the perception of quality.

 

Cynically, they will often offer a solution to one complainant on condition that they don't tell anyone else. 

Thanks @saveasteading. It certainly is one of the big companies. They can try to blame whoever they want, but they are ultimately the party responsible to deliver a product that meets specific quality standards to someone who has made a great financial commitment! Would be good to see if, as you suggest, there is someone on this forum that has experienced a similar situation.

 

After having raised this issue over a month ago, I might consider sending a letter to the CEO. So far, the developer's "technical team" are still dealing with my queries... There are thousands of new homes planned in my area for the coming years, so I reckon the local press would be an interesting route. I could also consider raising awareness amongst my neighbours!

[saveasteading]

There have been many reports of much worse problems that were ignored, and of very nasty tactics by developers.

Therefore be firm but reasonable at all times, and have an independent person confirm the situation in writing and with samples and photos. Does not have to be an expert when it is so simple.

This is a good one for the press as it is easy to understand and difficult to argue against.

But first write the reasonable letter with a 1 month deadline (response by xth January) before you take further action. Recorded delivery.

[Temp]

Our plot was a field on clay. We scrapped the top layer off (about 6"?) and replaced it after construction. We also put in land drains. Fast forward 13 years and the clay is still an issue for the lawn. I reckon it would  take an awful lot of topsoil to permanently improve the ground. Perhaps a foot or more as worms turn it over to quite a depth? 

 

My guess is they may offer you topsoil but before you rush to accept don't forget you may need to remove what you currently have to avoid raising ground levels. 

 

 

 

 

 

 

[TonyT]

Get some sand in there and some air you will soon have a good lawn!

[joe90]

Yes I added all the leftover sharp sand after the build to our soil, also found that the council green re cycling, turned  into soil conditioner is free if collected or you can pay to get it delivered.

[Thorfun]

before self-building we bought a new build and our garden turf was laid directly on builders rubble and clay. it was shocking and sank in places. neighbours had the same issue and they complained and eventually got them to put topsoil down and turf it again. we couldn't be bothered in the end as we were selling up to self-build.

 

but as has been said above there will definitely be resistance from the builder but stick to your guns and get the topsoil put down.

 

good luck

[Makeitstop]

Ebrin_Devon,

 

Can you share who the developer is?

 

I have experience of a similar issue with Redrow (who at least listened to peoples concerns when I went through this, unlike some developers)

 

They had to be pulled on ground levels at rear of the property, had to be told the topsoil was inadequate and also had to be pushed to install a land drain along one side where the ground was sloping toward this rear garden. It was pretty sticky soil and became heavy clay at a depth of approx 12", although it had pockets of all sorts in it. Some of the stone buried in there was more substantial boulder than 2" stone or anything easily handled. It was ridiculous.  The larger developers will always leave all kinds of crap under the surface, because it costs too much to do anything more.  

 

For your current situation, I'd say you need to remove what you have that's half decent, then cut out to depth of maybe 250mm minimum. From there, ensure that there is sufficient drainage to ensure you dont get excessive water trapped below your decent soil. Some level of gradient is wise, as is a very gritty layer of soil below a fairly sandy upper layer of topsoil, to help with good clean drainage. If you are looking to use turf, then it'll appreciate that, along with good exposure to sunlight.

 

Sadly, people in new build properties often seem to wonder why the lovely lush green turf they "had" became a patchy bog of dying grass, bare earth and moss. It's mainly because none of the above has been sorted out.

 

Push them to at least get you most of the way to the above conditions and you will be going in the right direction.

Edited December 20, 2021 by Makeitstop