New lawn

m_tariqs

Hello. I am in the process of getting someone to do my garden. I'm having approximately 5.6 meters by 6.5 meters of turf laid minus an 8x6 shed. The gardener has given me quite an attractive quote but i just wanted to run the technique by yourselves.

* Currently there is a dip of 20cm from the patio to grass  (ill post pic later).
* String laid from patio to end of garden  to indicate slope downwards to fence and to aid water flow through fence to field. May drill holes in fence to aid further waterflow.
*All weeds to be dug out, a substrate to be laid and then 2 ton of top soil spread over the substrate, which would result in approx. 6 inches of top soil over the substrate. This will also result in no dip from patio to grass i.e. all one level
*No substrate around the borders to allow growth of bushes
* Mid wear turf to be laid over top soil

I'm ok with everything just a bit nervous of the substrate. Gardner says if you fill just with top soil its going to sink and pool. What is substrate, is this the right thing to do ?

Many thanks.

K67

Best ask the chap supplying and laying it for a sample. If he means a membrane what you don't want is a cheap plastic one but a proper geo textile.
As to whether it would prevent dips I don't know.


PS if you just slightly crop your photo it will load the rightway or take a landscape one. The website seens to be having trouble with portrait photos

m_tariqs

Thanks. He mentioned it was a growing substrate. Like little pieces of light weight rock. Ill try and adjust the pic

K67

I thought its the sort of thing you put down under artificial grass.
Most grass is laid on levelled top soil and often sharp sand is used on top but as he is the one recommending and doing the work  i certainly don't know enough to question his methods.
Ask about a guarantee for his work and get an invoice in case there are problems afterwards.

JennyJ

If the drainage is poor, adding grit or similar to the soil will help, but I think I'd be inclined to dig it into the soil first, before covering with the new topsoil.

What makes lawns sink/subside in patches is insufficient/inconsistent firming of the topsoil (here's a video https://www.youtube.com/watch?v=J2Tv-ML36r0  firming starts at about 1.50 - I have no connection with Alan Titchmarsh or his sponsor, it was just the first thing that Google found).

Loxley

I've no idea what he means by 'substrate'. I've heard of green roof substrates - they're basically crushed aggregates with some composted green waste. Not sure why he would want to lay a lawn on that (unless it's on a green roof!) so he must mean something else, it's a bit of a vague word.

Does he mean subsoil?

m_tariqs

I will find out before proceeding

m_tariqs

Hello. Thankyou for all the advice here, it helped me from rushing into the job. I asked the person about the substrate and he came back with limestone base. I wasnt happy about it so did not proceed. I have decided to prep the soil myself and just take my time. Hope its ok to resurrect the post.

As things stand there is a lot of stone and weed in the current soil.

* So im thinking of using resolva and spray all over the grass and weeds

* I have already removed 5 bags of hardcore from the soil and am now left with small pebbles and will do a few more passes and keep removing

* Will use a fork and rake on soil and get ready for turf or seed at some point

* There will be a lot of topsoil going on top, starting at patio about 20 cm in depth with a gradual decline to fence

Things im worried about are:

1. How clean (stones) does the soil need to be before the top soil goes in? Possibly looking at 10 tonne in total, eventually.

2. If i use resolva will this hamper growing grass on same soil in future

3. 20 cm of top soil makes me apprehensive that it will be too soft and start sinking

Apologies for being a bit pedantic about things, but just trying to do the right thing.

Many thanks.

K67

Hello again!


Resolva works on plants and wont linger in the soil.

Stones will work their way to the surface so you could be there till next year. 

Yes 200mm of soil is quite a lot, can you borrow a roller to consolidate it.
Failing that build it up gradually and do  the funny walk up and down where you shuffle along -  there is bound to be a video  This one is good https://m.youtube.com/watch?v=J2Tv-ML36r0

Then you rake again  shuffle again and keep doing this until your heels don't sink in, rake again then do the grass.
After all that by next year it will still have sunk in places!

m_tariqs

Thankyou. The video is very informative