Received a call from the builder last Monday to discuss the happenings with the build.
Apparently, we haven't been seeing much action on site as they have been having difficulties finding a stumper who would be willing to travel to Kilmore. Given that they have not built a house on stumps for about 10 years, they didn't have many contractors on their books to choose from.
All is good now - they have now made contact with a stumper willing to travel (who comes highly recommended by the surveyor) and everything is good to go again.
Unlike a slab house, we will not need drastic excavations done for our drainage as it will all be underslung under the floor joists and connected to the outlet at a later stage. The only drainage required at this stage will be for the laundry, which is being built as part of the garage slab. The garage slab should be done this week, and once that is set, the stumper will come in to do the stumping. Keogh expects all this foundation work to be completed in the next 2-3 weeks.
At this point you may be asking yourself, why even build on stumps at all?!
Well...when building on completely flat ground, building on a slab is far cheaper than on stumps. However, as the land slopes more and more, there reaches a point where building on stumps becomes more cost effective because it basically offsets a lot of the excavation and site works required to build on a slab.
So let's imagine for a moment that we had a graph showing the cost of building on stumps vs. slab, where cost is the y-axis and land slope is the x-axis (let's just simplistically leave it at the single level of land slope at the moment). If both graphs are linear, with stumps starting out as more expensive, as land slope increases at some point the cost of building on a slab and on stumps should meet and cross over - eventually resulting in some cost economies to building on stumps.
While our block is not quite at the point where building on stumps was cheaper than a slab, we were quickly approaching that crossover point. Additionally, the added benefits of stumps (and personal preference!) over slab pretty much sealed the deal , making the extra costs worth it in our minds. Like everything, it all comes back to the $$$....from what I have read, this is the main factor that dictates the popularity of the slab in modern buildings.
For our personal situation, we weighed up the pros and cons of stumps vs. slab and came up with the following list:
PROS OF STUMPS:
- Extra space under the house for storage
- Insertion points for ducted heating can be installed under the floor (more energy efficient, as hot air rises)
- Ease of service additions later if required
- More in keeping with the traditional "feel" of Kilmore
- Easier to check for termites
- Slabs are vulnerable to water and roots - water or roots can crack a slab, and once moisture gets in this can cause concrete cancer that can never be detected until it reaches an advanced stage
CONS OF STUMPS:
- Bearers and joists are comparatively more expensive than concrete
- Takes longer time to build on stumps
- Other items required to be incorporated into the build to attain a 6 star energy rating (e.g. require underfloor insulation)
On balance, we have more pros for stumps than we have cons, which is why we decided to take this option - that is not to say that slabs do not have their pros either, it just wasn't going to be as suitable for our situation.
