Sandstoning the apron

part III

Steps revisited

Having completed the perimeter we now had the heights finalised all around the building and we were ready to tackle the front steps.

We were also quite pleased with the system we have developed for the side steps and it seemed obvious to continue in that style.

Defining the boundaries

This time we used 3 pins per step since the steps were up to 3 metres wide and curved to boot.

The top and bottom steps were done first and we worked towards the middle.

Reinforced concrete pins were constructed to define each step and a curved formwork made to be used to shape the front of each step.

This is what it looks like from the bottom.

The top and bottom risers are poured and they both have their sandstone facing poured in place.

You can see the string lines used to determine the pin positions and the top and bottom risers in place.

The string lines and some of the pins are visible to the keen of sight also.

The bottom riser has been poured - we chose to pour the concrete with the sandstone facing in situ to avoid the hassle of having to face the curved surface at a later stage.

Some more steps (risers only) poured.

The curved formwork (2-sided) is visible - an exercise in economy, we used one face for the top concave steps and the other for the bottom convex steps.

The light coloured stuff under (photo-wise) it is the concrete. They are fairly massive as we used the earth as the internal face of the forming up and it was easier at times to mix an extra bucket of concrete than to fiddle around getting the earth neat and tidy.

Here you can see the rebar in place - nicely curved by the three concrete pins and contributing a bit of tension (stress) to the final structure.

The formwork needed to be leveled side to side and front to back as well as being set back and up the correct distances.

Despite the rather casual approach to the forming up all the risers ended up within 2 mm of where they should be - a tribute to the versatility and flexibility of the material.

At the bottom of the steps the slope had shallowed out so that we couldn't use the earth as part of the formwork without creating unnecessary (IOHO) work.

We used some bracing ply and clamps to retain the wet concrete.

Defining the sides of the stairs

The risers have all been poured and now we need to identify the edges of the steps to determine the boundaries for laying once again.

Electrical conduit is a good flexible, not-easily crimped, material to define a curved edge.

Once completed there was some more earthmoving and filling with crusher dust to create the level surfaces to take the sandstone.

You can see the pieces ready to place, by this stage the trusty wheelbarrow had been converted to a stone transporting platform.

We spent days constructing devices to minimise the effort of moving the slabs of sandstone - in the end the wheelbarrow was streaks ahead of every other idea we had.

Sometimes you just can't beat simplicity.

The sandstone laid to form the step treads, we had by this stage decided to use 10mm white quartz between the slabs in preference to spending months grouting them.

This also means we can easily lift a slab should we need to get at any of the pipes beneath them.

But it also meant that we had to use mortar between the slabs at the perimeter to prevent the quartz running out.

What a delight to be able to walk up and down that slope in the wet without taking our lives in our hands!