So Urban Utilities has finally come to the game and provided an online GIS (that stands for graphical information system) so that we humble mortals may identify the depth and diameter of their precious underground infrastructure (ie pipes).
Until now we’ve been using the free Dial Before You Dig website to identify what services are located on a property we are interested in, and a Dial Before You Dig is still an excellent tool for identifying whether buried infrastructure might affect your project. So probably run a DBYD first.
Click “I agree to the above terms and conditions.”
Type in an address in the search bar.
Click on a line (a sewer line) or a circle (a sewer access hatch) and you’ll be able to identify the depth and diameter of the Urban Utilities sewer infrastructure near you (so long as you are in an area serviced by Urban Utilities).
If your property is mid-way between two access hatches, you’ll need to interpolate the depth of the pipe between the two known invert levels because Urban Utilities does not give invert levels along pipelines – only at specific connection points and bends.
A client came to me for a second opinion about a quote to underpin his residential property in Queensland. The quote was from a local builder for 25 underpins to an approximate depth of 2.5m in order to ‘stabilise a single level house.
The quote was based on an engineer’s assessment. A geotechnical engineer had also attended and provided the results of a soil investigation. Both good signs.
So on the face of it, everything seemed legitimate. However, once I dug deeper the justification for spending so much money was very thin.
So very thin.
So how do you, as a homeowner, evaluate a quote for underpinning from a builder and determine if you’re likely to get value for money.
Let’s go through my independent assessment process together.
Have you got a house on a sloping block with drainage problems?
The queries we get go something like this:
Hi. My house is on a sloping site (slopes from the back towards the front) and water gets in under our house when it rains. The ground under our house gets wet and then takes ages to dry out. Sometimes the water gets into the downstairs rumpus room, storeroom, laundry, garage slab (pick one or two!).
How can I stop water getting under my house? Should I use an ag pipe and or should I install a better drain?
Well, we have some ideas (and a video) that might just help.