A Little House at No. 18

The ins and outs and inbetweens of building a new house in Little Howard St, Fremantle


Finishing the flooring – part 2

Over 3 years ago we vaguely remember laying a concrete slab which would one day would become the floor we now call home. It seems so long ago. Just enough time to increase the surprise when we recently had the concrete polishers back to run their wet diamond polishing machines over the floor again to reveal a nearly forgotten treat. If you were to skip back to the earlier blogs of May and June 2013 you will get the initial concrete floor project happenings.

But now at the pointy end of our project we have an exposed aggregate slab with 3 different colour mixes raked together, seeded with resin filled cowrie and cone shells, river stones, bauxite (pea gravel), random trinkets (distinctively visible forever more) and our houses position, expressed in Latitude and Longitude shaped out of brass and embedded in the concrete at the front door.

Besides the plumber, the concrete polishing guys have the privilege of visiting a construction site well in its infancy, long before the scale and form of the building have begun to appear, and during the “icing on the cake” stage, just before the “keys are handed over”! It must be a real perk of their trade. It certainly was for them on our project anyhow. When we last saw them, they covered the honed concrete surface with a screed which acted as both a filler for bubbles and pitting and to protect the surface throughout construction. This final step of doing the polishing and sealing has been more of a psychological completion than we were expecting.

The boys from APCG (All Polished Concrete Grinding) must have a good memory because they arrived and immediately recalled the detail and features of the floor that we all discovered for the first time, 3 days after the slab was initially laid. They run a very well organised and methodical operation and within a short period of time had the large polishing machine up and running on the floor to start the final steps of the process.

This involved grinding the surface several more times and another layer of screed in the process to fill any newly appeared cracks, pits or voids. Starting with quite a course (80 grit) diamond polishing disk and working up to 400 grit, each time the surface became smoother and with it more physical texture would disappear as the visual texture would show greater and finer detail.

It was fascinating to see the many and varying “ingredients” making up the contents of the floor conform to the actions of the polishing stones, all developing a uniform smoothness as one body of mass. There is so much fine detail in every exposed piece of aggregate. The closer you looked the more amazing things you see. However, on a larger scale, from the mezzanine floor the subtle transition from dark black concrete to the lighter “natural” concrete can be seen more obviously.

The final day saw the application of several coats of sealer before we could stand and admire our efforts in all its glory. The journey to complete this floor has been a process to say the least. Being laid on pre-cast planks, with hydronic floor heating water piping, to laying the one floor using 3 different coloured concrete mixes, seeding with an array of trinkets, shells and unique stones as we went along and including a feature brass inlay have all involved many hours of research to allow us to tackle our ambitious dreams. Now all we have to show for our efforts is a floor we get to call our home and enjoy for many years to come.

I have found myself saying a little bit lately, “if I knew then what I know now, I would never started this project” but the comment itself by no way reflects any regrets. It just highlights how crazy and alternative some of our ideas were and in hindsight it was great that we were not as wise in the beginning. The ideas were purposeful and original. And achieving them was only limited to the time and effort we wanted to invest in solving them and transforming them into a reality.

One example was that we wanted a homemade end grain parquetry flooring in the kitchen, similar to that of chopping boards. Made out of scrap timber offcuts, it sounded like such a practical, good looking, hardwearing solution for all the small bits of timber remaining, it just ticked so many boxes that there seemed like no better alternative. Now that we were ready to install a kitchen, the time had come to build the long foreseen floor. Plus, the main slab had been poured with a 25mm stepdown in the kitchen to allow for the floor so it was not a matter of what we were going to do but how we should tackle it!!

Best place to start was by going through the “scrap” pile and finding all the offcuts that were about 500mm long. Chunks varied from 30 x 30mm to 150 x 200mm offcuts from the main truss beams. The aim was to find as many random dimensions and colours of jarrah possible. We started by planning and thicknessing the pieces smooth so they had square corners but removing the minimum amount “waste”. Once we had a large enough collection of machined pieces, we cut a 19mm slice off the end of each to create a random collection of tile-like blocks. For reasons of unimportance and reasonlessness we decide to arrange the pieces to fit millimetre perfect into a 325mm square pattern. In the big picture, this would eliminate the possibility of ending up with tiny voids between randomly placed blocks, working across such a large floor area.

To a great extent, the pattern “made itself” quite easily and fashioned “appropriately random” to end up about 90% resolved. To complete the puzzle, some of the remaining tile-blocks were marked down in size one or two dimensions to fit snuggly, completing the large square tile, each one consisting of about 24 individual pieces. The longer bits of pre-machined timber that corresponded to the re-sized blocks were then re-machined to bring the whole piece down to the required dimensions (more often than not, this meant only removing around 5mm or so).

By now we had 24 pieces of random timber that were all about 500mm long. If you laid them down in a neat stack, and in the right order, they would form a perfectly solid cuboid (a rectangular cube) with no gaps. If each of the individual pieces was then meticulously cut into approximately twenty 19 mm slices you would then have 1) Lots and lots of little blocks of wood everywhere. 2) Enough blocks to make twenty 325 x 325mm squares of end grain timber that just oozed character. You could seriously hang them on the wall as a piece of art. By the time we had completed this stage of the production we were two days into the process and we had just made 2.2 square meters of end grain parquetry. As we had over 8 square meters of floor to cover, all we had to do was repeat the process another 3 times and we’d have enough blocks to do the kitchen floor!

After 6 days of machining, measuring, cutting and sanding, we had hand produced around 1,560 pieces of end grain parquetry flooring. Enough to pave our kitchen floor.

In order to fix it permanently to a concrete pad underfloor we used a Sika primer MB (moisture barrier), a bright blue epoxy resin, that when spread over the concrete floor dried like glass and provided a perfect surface to glue the parquetry to using Sikabond T55, a highly flexible polyurethane timber flooring glue. The parquetry was laid like tiles, one piece at a time. We made a few jigs to help us pre-arrange the pieces from the piles nearby and transport them to within easy reach of the waiting, glue smeared floor. Within 2 days we had the nearly 1,600 pieces arranged and firmly set onto the floor.

After leaving the floor for a good 5 days to let the glues set, we got the floor sander black to gently run over the end grains with a large 120 grit rotary sander to lower any corners and give it a pleasant feel under foot.  The final task was to preserve the timber and protect it from the potentially staining liquids it’s likely to endure in the future. The finish was largely experimental but also, research showed, historically commonly used on strip parquetry. This technique involved rubbing warm bees’ wax (I used our Jarrah bees wax) across the finished surface before warming it with a heat gun until it melted into the grain of the timber. By also “scrubbing” the waxed surface with a plastic scourer whist the wax was still liquid aided the penetration and even distribution. I then used a buffing cloth to wipe the residue off. This initially left a very shiny and slippery floor but made the timber grain water resistant, bright in its colour and feature and a good start to its life as a solid hardwearing floor. Since the initial waxing I have applied several coats of linseed oil and bees wax cold liquid mix (home made) and the floor “evolves” with each application. We are very pleased with the kitchen floor and how it looks and feels beneath bare feet. We are also very excited to see how the floor will mature over time. Unlike most flooring types, end grain parquetry has a real reputation for outlasting generations, reportedly only ever getting better looking and feeling with constant use and wear.