7 Secrets to Good Concrete with Peter Colquhoun – Part 2

Part 2

Everyone wants to know the secrets to achieving the perfect pour when laying concrete.

So we asked our resident architect Pete Colquhoun for his tips on getting the best results for your project.

He says there are seven key considerations that you should take into account when planning any type of concreting.

Today Geostone brings you Part 2 of this 2-part mini series to help you with your concrete selection and concrete pouring. If you missed Part 1, read it here.


When is a good time to call in the professionals?

There’s an old sailing term, if you think you need to put a ‘reef knot in’ – then you need to put a reef knot in. In other words, if you’re in any doubt, get some professional advice or have an emergency concrete contact handy. If you are attempting a simple concrete pour on the ground or somewhere in the garden then sure, have a go – but anything that involves structural steel, formwork or polished concrete floors should be left to the professionals. If you want to be involved, offer to push a wheelbarrow instead or stand back and watch them do it in a tenth of the time and achieve a better result than we mere mortals will ever dream of. Also if cracks or breaks appear in concrete and structural steel is exposed, seek some engineering advice before you attempt to patch it. If salt air or other contaminants get into a slab that is then covered up, the steel can slowly rust and you end up with ‘concrete cancer’ which will end up being quite costly to repair.


How do customers choose the best concrete colour or aggregate mix for their home?

I always say keep it simple. Darker coloured concrete will certainly make a statement,  but too much can become imposing or corporate. Lighter concrete is safer in the home and works well with timber finishes. Large concrete areas can sustain larger aggregates, but if you’re doing a smaller area choose smaller aggregates. You can view the Geostone exposed aggregate and coloured concrete range available in your local area on the Geostone website, or your nearest display centre.


What are some of the differences to keep in mind when planning and pouring a polished concrete indoor floor vs an outdoor concrete surface?

The main differences are practical. Internal slabs will have a higher level of finish while external slabs require a gentle fall to allow water to run off. The other main difference is you are more likely to slip on an external slab if it’s wet, so exposed aggregates and coarse finishes are advisable.

In terms of planning, internal slabs need to be carefully coordinated in and around the rest of the building program. Builders often like to get the floor slabs down as early as possible in a new build or renovation, which then gives them a solid surface to work off. The finishing of indoor slabs such as grinding and polishing should take place toward the end of the job to avoid damage while the rest of the work is completed.


What is a popular way of using concrete in the home?

One of the great mid 20th century modernism design features, still quite popular today, is continuing the look of an internal slab across the threshold and into the outdoor patio area. While a seamless transition is aesthetically pleasing, a step or at least a drain will need to be put along this junction to stop water coming into the home. Sometimes practicality must rule over aesthetics and careful detailing must be considered when you are trying to achieve an ‘indoor-outdoor’ look.


Any final words of advice for people considering Geostone decorative concrete in their home?

Concrete should be considered more than just a floor surface, driveway slab or paving material. Today concrete is used for a variety of functions including walls and ceilings as well as internal seating and benches. Because of this versatility and the various finishes available, concrete has undergone a renaissance and is very much considered the go-to material in contemporary design.

Remember though, either in its raw or decorative state concrete is still only a building material and it won’t remedy a poorly planned house. By this I mean you must understand your renovation or new build in terms of the first principles of good house design before choosing any building material. These include:

  • Getting natural light and ventilation into the home
  • Creating various family zones for congregation and private retreat
  • Exploring the potential of circulation zones like hallways and stairs into the plan
  • Creating flexible living areas that may have dual or multi purpose functions

Once these principles of good planning are understood, a material like concrete can then be put to its greatest effect. While as a material it won’t fix bad design, concrete will certainly make good design great.

Good luck with your selection and pour!

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