Forgot the kitchen drain has roots through it (which I can control reasonably well with copper sulfate) and judging by the extra green patch of lawn we get (and the sewage pipe that runs directly under it) I can conclude what has happened there as well haha
Norm, I also catch the water off around 1/4 of the house into several drums and 240L bins. Then I just use a submersible pump to drain it out. I also have a mate with a double garage under the house - complicated by the fact he also has a double carport at the front. He is forever worried the drain will fill up and flood.
I figure the significant amount of moisture in the fresh mulch causes the steam. Don't be surprised if you need to pressure wash the driveway underneath as the heat rots the bottom stuff quick smart.
Gadge, the gutters are what worries us the most (and the carport) so that will definitely need doing before winter. Fortunately they haven't rusted through, however the sagging directs water the wrong way. Only 2 spots have issues, and thats presumably where the water runs the wrong way over the seam. I have drilled a few holes to funnel to water out into the garden.
I have been trying to work out the pipe material as getting rusty water has to be steel of some description. The only part I can think of it the HWS tank as the rest should be copper in a 1987 house. But, only certain taps are affected, the laundry runs clear after approx 9l, but the bathroom can take 40l before it runs clear.
Anyway, probably will have plenty of time soon enough. Breaking news 5 mins ago another container ship over here with a covid out break, so we will be beyond stuffed soon enough.
