(or… garden project days 4, 5 and 6)

Seeing as Vinny asked about levelling a garden I thought I would turn this update into a bit more of a “how to” post.

One thing to bare in mind having done this for pretty much the first time is that beforehand I thought it would be very complicated and hard to get everything level, but having done it, it was actually pretty simple*. So if you are worried about giving it a go I would say don’t, stop procrastinating, and just get on with it 🙂

*That’s not to say it’s not “hard” work, but it just wasn’t as complicated as I thought it would be.

A quick note… I am guessing some people may just want to know how to level a garden without actually laying a patio over the top, for example if you just wanted to lay some turf. I’ll write a few notes as I go about that as well but to be honest unless you require uber flat grass (putting green in the garden anyone…? 🙂 ) then you can just do that with a bit of grunt work with the shovel and use you eyes in my opinion. Anyway with that said here is…

How to level a garden and lay a flat patio base

1. Work out how far you need to dig down

For a patio base, you need it between 12-20cm below the final level. This allows 5cm for you sub base, 2-5 cm for a ballast/sharp sand  to help level it out, 3-5cm for the mortar level and 2-5cm for the patio slabs – obviously change this according to how you want each level. There are various ways of doing the base, for example you can miss out the mortar level entirely and just lay straight on a sharp sand level, so watch a few youtube vids, here are a couple with the different methods:

Please note there is an disproportionate number of Australians knocking about on Youtube patio laying videos, so viewers discretion is advised here 🙂

I did my layers as follows:

  • 5cm old broken up concrete blocks I had laying around the garden
  • 3cm ballast
  • 2cm sharp sand
  • 4-5 cm cement
  • 35mm patio slabs

So as you can see I was trying to dig around 18-20cm below the final level I required.

Important Note: A patio next to a house needs to have a final finished level around 15cm or two bricks below the damp proof course of the house (it’s the weird black line you can see in between the bricks in case you didn’t know what that is!). Mine ended up a brick and a half… I’m sure that is also fine 🙂

 

2. Dig out down to the level required.

Simple grunt work required for step 2!

If you are only levelling for grass/turf then you don’t need to dig down that far, you just need to get it low enough so that there are no humps that go below your final desired level, plus and extra 3-4cm for the turf if you laying that on top.

It might be worth getting some builders line and some metal or wooden pegs, and running that across the area a couple of times. Make sure the lines are level using a spirit level of course!

You could also do this with the patio base if your starting area is really bumpy, but I didn’t bother as mine was already quite level – I just did this by eye by drawing a chalk line on my wall and roughly following it.

For the patio base, it doesn’t have to be mega level or flat at this stage so don’t beat yourself up about getting it totally flat.

For the garden/turf levelling – pretty much all you have to do after this is put some earth back into the bits that are now under-levelled. It will help to break up the earth nicely with your shovel either before you put it back on or as you are doing it, so the mud is finer and you can spread it around easier and get it more level. You can then just rake it nice and level with a metal rake, something like this, and job done, go and have a cuppa or a cold brewski of your choice.

 

3. Stick in some wooden pegs and get them all level

Back to the patio base then. You will either need to buy some wooden pegs or make them. I made mine from some old fence posts I took down when I dismantled the decking and just cut them once with a straight cut and then again with a diagonal cut to make them easier to hammer into the ground:

My home made levelling pegs

Hammer them in – I used a rubber mallet here as I bought one for use later on when laying the actual patio.

Start in one corner of the area where you know the exact height you want your base to go up to, and hammer it in so it is the level of the first layer you want to compact if you are using a compactor. For example mine was level with the ballast layer, because I wanted to compact that layer. If you aren’t using a compactor (although I would highly recommend you do!) then you could put the pegs at the height of your final non-mortar layer.

Put in a peg every metre or less in a square formation, if you go over that distance it becomes hard to see if things are really that level in between the pegs. Use a long spirit level or a flat piece of wood with a level on top of it to make sure the pegs are all level, like this:

Important note II: When levelling a patio next to a house, you need it to actually slope away from the house so that water drains away properly and doesn’t sit next to the bricks. An easy way of doing this is to make sure each wooden peg is not actually 100% level, but the bubble is nearer to the side nearest the house. If you get the bubble edge either on the side nearest to the house or slightly over it, then you should get a very small drop which will drain water along nicely.

You could also just measure the drop along the actual wall (if you have one to work with such as I did as there were two walls I was laying against) and draw a line on in chalk. They say the drop should be 1 in 100 to 1 cm for every metre.

Once you’ve finished it should look something like this:

At this stage, if there are any obvious bumps or troughs you should be able to see them and you can excavate/fill in any earth as needed. Again it doesn’t have to be like a snooker table here, as your sub base and subsequent layers will do a lot of the levelling for you so don’t tear your hair out over it.

4. Add in your sub base and compact if necessary

It will be much easier to buy some Sub base MOT 1 (no idea what that stands for, but that’s what it’s called apparently!?) that to do what I did and manually smash up a load of extremely thick and heavy concrete blocks, but it seemed silly in my case to have to get rid of the blocks and then pay for some extra sub base. ANYWAY… be prepared for a lot of heavy lifting here and in subsequent steps. 25KG might not sound a lot but once you’ve lifted the 30th bag of the stuff… man it starts to hurt!

Anyway here is a pic of me starting to lay my base:

 

Here is it nearly finished. Naturally, I played the Tetris song 1 on loop while I was doing it to make this more fun 🙂

And another view here:

As I say hopefully you will have a much easier job of just poring out some bags/wheelbarrows of some nicely already broken up sub base and then you just need to rake it into position and compact it. A compactor is a very heavy machine that vibrates and flattens the base levels for you, and it looks like this:

Cost me about £50 to hire for the week… money well spent!

I couldn’t compact my sub base as it was too “chunky” so I left it as it was.

 

5. Add in your next layer(s) and compact, repeat till fade

So now depending on what other layers you have, you just need to add them, get them looking level compared to the pegs and then compact yet again. The compactor should do most of the work in getting it relatively level from here but I guess if you notice any huge outcrops of base then you can get the spade out again.

So for me this step meant adding in ballast and compacting. Here is a picture of my ballast level before I compacted it:

 

You may not even have this level so you would skip straight to the sharp sand level. This is the final level which should get things really nice and level once you’ve compacted that.

Remember to use the rake to get things looking nice before you use the compactor.

Nearly two weeks off and this is the closest I’ve come to raking a bunker! 🙁 😀

And here is a picture after the sand level has been compacted:

As you can see there are a few lines of sand dotted about, this seems inevitable as when you turn the compactor it is so heavy it will always make a bit of a line.

 

6. Screed the sand level with some flat wood and recheck final levels

Screeding simply means dragging a piece of wood or flat edge over the surface and taking off any excess sand. I found that hardly any sand came off during this process which meant that the compactor did a bloody good job of the whole thing! But saying that, it was still definitely worth doing the screeding process, as there were a few tiny peaks and troughs still there.

Also check the level of this final base layer with your spirit level. Remember that it should be sloping away from a house so in that instance you don’t actually want it 100% level (and certainly not sloping towards the house!)

Here is a picture of me doing some screeding:

 

 

7. Get a brew on / grab a cold one from the fridge for a good hard day’s (or 2, or 3!) work done!

That’s it!

 

I’ll leave you with a few more pictures of what I got up to on days 4, 5 and 6 of the garden project!

Patio slabs got delivered and taking up precious parking space outside our house!

 

Another view of the semi laid base and huge pile of earth

These used to be black believe it or not!

My finished “Crazy paving” style sub base

Both of the raised flower beds now dismantled and moved out the way for now

Found this little fella living underneath one of the raised flower beds!

Notes:

  1. The 90s “rave” version… obviously!