When we first did the patio we wanted to use up a bit of space behind the garage. The area was below the rest of the patio. It consists of a narrow strip into which I could only just fit the builders’ “large” paving slabs. It was also low enough down that we needed a step.
That arrangement lasted for a large number of years and went through several iterations. At one point it housed a plastic shed full of children’s toys.
For the grand rework project I wanted to lift it to the same level as the rest of the patio. The step downwards was irritating. I’d also paved it with a mix of left-over building materials. This included a mix of some of the builders’ 900x600mm heavy slabs, some of the newer 450mm square slabs, and a little bit of poured concrete. Did I mention also that the space originally wasn’t straight-sided. The builders put the fence at a slight angle to the wall, with the narrowest part at the entrance.
When I re-did the fence in 2018 I discussed this issue with my neighbour. He was happy for me to straighten it out to be a consistent width. It meant we also straightened out an area of slate-covered border on his side. I nicked a bit of land at one end, and gave him a bit at the other end. He now has a fence that’s parallel to his garage wall too. After building a straight line here (we moved no more than 10cm) I was able to rejoin to the line of the original fence. The fence is now a consistent 105cm away from the garage wall. The original patio was 90cm deep, so I had a few extra centimetres I could use for paving.
So having made myself a straight space two years ago, it was time to exploit that.
To raise the level I would need to add about 120mm. I tried initially to lift some of the old slabs to clear out the whole base and start again. That proved to be a nightmare. I switched solutions and decided to just “chop” the edge off the old slabs so I could lay a course of heavy blocks as a base for the new area. When I say “chop”, I should more correctly say that it was a troublesome activity, which broke a number of lightweight tools and generally caused a lot of swearing. It was hard going and I generated a lot of waste concrete.
I eventually managed to break through the surface of slabs and get down to a combination of hardcore and clay, which is a lot easier to work with. It was dry enough that I could separate the two and use the hardcore as aggregate in a concrete base. That’s just as well, because I was doing this part in April, when it was quite hard to get hold of building materials. I had a couple of bags of cement and some sand left over from the fence work, and it was just enough to get the job going.
When the shops reopened, I was able to get mortar and I quickly upcycled some big concrete blocks that next door gave me (they used to be a base for their shed). They were of the very heavy 300x200x150mm variety. These formed a nice base which I subsequently left for a while until I had finished a first pass on all the planting beds and was ready for some actual paving.
As with the fence, I wasn’t really sure what I was doing when I started laying paving slabs, and the area behind the garage is both hidden and only accessible by carrying materials all the way around the house. So this was my starting point. The next job I had to do was to raise the level up to where I wanted it. I hadn’t really planned this bit. However, I’d bought a lot more breeze blocks than I needed for the retaining wall. These were cunningly just thick enough to bring the level to where I wanted it (at the back at least). They also cunningly fit four across into the 800mm gap I needed to fill. The previous paving made a stable base, I just to chucked down a thinnish layer of mortar and dropped the blocks straight in.
Closer to the house the level came up a bit, so I had a thinner layer to fill. I bridged this by making some concrete out of the rubble. I also had about 300 block paviours left from another past exercise. These had been going to waste for 8 years. I wouldn’t build walls out of them, but I reckon they’re more than adequate for filling a hole. Even closer to the house I only need 50mm of depth, which I just filled with some hardcore. In fact, I suspect this bit of patio base will still be there after the apocalypse. At the end of this, I’d managed to make myself a flat platform of about 5.5m long and 1m wide.
This put me ready to do a bit of actual paving, so I began on that one weekend with a bit of assistance from Ami, who helped me mix some concrete and paint some of the slurry. We also had to cut slabs for this section as it wasn’t possible to make a 1m width without cutting slabs.
As an extra learning point, I’d drawn scale plans of each area of the new patio so I knew what slabs to lay where, but for this area I’d drawn it as if I was starting at the house end. I couldn’t work that way due to lack of access, so I was working all back to front. I had to begin by laying slabs at the opposite end. It sort of worked though.
Laying the slabs turned out to be fairly uncomplicated. It’s a little slow if you mix the mortar by hand, but we got into a nice routine of mixing mortar, laying flat bed, and then putting a slab on the top. We used a semi-dry mortar, so the bigger slabs were actually OK to walk on straight away, but it was still best to be working by reversing out of the narrow space. I spent about 8 hours of total effort in laying the slabs here. It was awkward having the wall of the garage right alongside us, and I left rather a large joint to be filled, but I couldn’t really do it any other way.
The slabs then stood untouched for a few more weeks while I got on with a few other parts. Finally, at the start of September, I got around to experimenting with the joint filler and sealant. Again, when I started I had never done it before. The instructions said to brush the filler in, but I found it easier to use a hand trowel and a small sweeping brush. The filler isn’t cement based, so it doesn’t leave grey strains. It does need to be wet throughout to stop it from sticking to the slabs. Once settled, you have to leave it in place for a couple of days to harden. When it’s hard you can use the edge of a trowel to scrape the surface to remove irregularities, high spots and so on. It was quite easy to do and the finish is really good.
The final stage of the process is to clean the slabs with a hydrochloric acid solution and then (after rinsing and drying) paint it with the water sealant. This only took a couple of hours on a warm day. I bought an “invisible” sealant rather than a “wet look” one. The effect is quite pleasing. The surfaces of the slabs look a little dusty and the original grain shows. When it rains they look a little darker, but the water doesn’t absorb into the surface very much. They don’t look as dark as untreated slabs.
Anyway, I finished this area behind the garage well before anywhere else. I like the overall finish and (as a bonus) I can use the space to store little-used outdoors items again.