Thread: Setsuna - A Goat Island Skiff build in Sydney, Australia

This is way out of my territory, but I do know water.

If the Pool is 50mm deep then it is that far off draining properly.

Just a thought... Whatever it's worth

G'Day MIK,

Thanks for the input . The problem is that I can't raise the building 50 mm . I have just done a bit of measuring inside and out so I now know that I "only" have to dig down about a metre on the outside of the house to get at the leak. A bit of galvanised deformed reo and several wheelbarrow-loads of concrete should shut that one up! The quotes around the "only" is because I'll be digging in a confined space with the threat of rain. Still, I'm no stranger to that combination of conditions - unhappily . (Note to self: supplies will need to be ordered before I start digging.)

And there's The Rock and its attendent strut to contend with, of course...

Another note: I've been digging and grading the path above the "chute", where the water is coming from, in order to re-direct the flow from the top of the hill down the path instead of the chute, and also to reduce the likelihood of it flowing over the top of the row of bricks at the top of the chute. That row of bricks will get some mortar shortly to help seal things up. Step by step.

Cheers,
Alex.

Do I see the top of an ag drain in the gravel already?
How far below the visible gravel is the concrete floor?
Are there any dips in the bottom of the trench under the gravel which would
allow water to pool rather than drain?

Footing for the pier to support the rock would be more... 'interesting' than the
pier itself. How much of what looks like erosable dirt is dirt, & how much is
rock? Might be worth using a diamond disc & demolition drill to cut a hole for
a pad. Then insert a thick walled galv steel or heavy timber pier cut to length
& packed.

Cured a similar drainage issue with our home when I was a teenager.
We raked out a trench, with a slight fall in the right direction.
Painted moisture barrier on the wall. Then got the bottom completely flat
& straight with sand, & lined it with plastic sheet forming a channel 6" or so
up the trench walls. Laid 50mm ag drain in it & back-filled it with gravel.
Of course, there wasn't a ruddy great rock hanging over our heads as we did it...

All the best with it mate. At least it'll get you out of painting for a while...
cheers
AJ

Hi AJ,

What sharp eyes you have :). That is indeed a (32 mm/1.25 ") ag line, and a peculiar beat it is indeed. There is a leak even higher up (near the top of the house) that I haven't been able to get at, which comes down the rock inside. I constructed a massive concrete block at the bottom (inside) that served the dual purposes of holding up one end of the ENORMOUS rock that the house sits on, and stopping other leaks. You can start to understand why the workswamp is so damp and why I've had so much trouble with surface coatings of various descriptions.

The ag drain threads through the end of the wall of the house, through the concreet block, and exits via a funnel shaped into the top of the concrete block. I'll post some snaps later to show what I mean - I'm having to dig rather deep (as it were ;) since this predates the boat by a year or two. The idea being, of course, with the ag drain, that the water flows down the rock, through the block and back outside and exits further down the hill (near some drainage-in-progress). One day I might be able to stop the upper leak(s) and make that drain redundant, but it isn't a priority as the amount of water from that source is relatively small.

The floor is around a metre (+/-) below where the ag-drain is at the uphill end of the trench - the height decreases as you move downhill, of course. I'll draw a diagram of the outside situation and post that, a picure being worth two or three thousand of my words ;).

But as you say, the silver lining is that I get to put off the painting for a while longer :))))).

Cheers,
Alex.

Who painted that lining silver?

As they say in the classics: Every silver lining has a cloud...

Now there's a thought - get MIK to do the painting !!
He did say he's good at it.

Originally Posted by b.o.a.t.

As they say in the classics: Every silver lining has a cloud...

Now there's a thought - get MIK to do the painting !!
He did say he's good at it.

Heh . What a great idea!

Well, I had an interesting time observing what was going on with the water during this morning's un-forecast RAIN. Isolated showers indeed - it were isolated rain, right on top of us . This neck o' the woods is known to be a bit of a rain-magnet...

I've discovered at least one entry point at the bottom part of the wall at the top of the house outside, and another possible one right at the top of the chute, also outside, but I'll have to dismantle what I've already installed to check that one. I'll probably go the whole hog and rip the rather poor concrete off the chute area and redo it from scratch. But that is a lower priority as the bulk of the water - the taddie-pond is about 10 mm deep at time of writing after being almost dry at lunchtime - is entering under the footings near the propped rock so I have to dig down the necessary 3+ feet/one metre to get under the gap 'twixt footing and rock and permanently seal it with concrete. And for which I'll need some dry weather.

I also spent some time today sifting through my various image archives for the concreting photos, and eventually found them in an unusual spot, a result of using the camera on my old Sony Ericsson phone. Possibly. At any rate, there's far too many to post in this Goat thread so I'll have to do some sorting.

Cheers,
Alex.

Dude! You need consult from a hydrologist before your whole house slides downhill. Plugging holes ain't gonna do it. You need to redirect the flow well uphill, before it gets to your house. Or someday you are going to find the living room down in the valley somewhere.

Originally Posted by AlexN

the bulk of the water - the taddie-pond is about 10 mm deep at time of writing after being almost dry at lunchtime - is entering under the footings near the propped rock so I have to dig down the necessary 3+ feet/one metre to get under the gap 'twixt footing and rock and permanently seal it with concrete. And for which I'll need some dry weather.

Meaning:
1. the water is entering the ground somewhere further uphill, & trickling flowing
down thru that awful bloory awful sandstone to fetch up against your wall/slab somewhere
under your existing ag drain ?
or
2. falling past the ag drain in the gravel beside the wall to bubble up again between wall & slab?

The second scenario is easier to fix, and doesn't need concrete... just the
profiling plus plastic sheeting I mentioned earlier.

Scenario 1 probably can't be fixed with concrete either. Not externally anyway.
Might be easier in that case to assist the water to leave quickly than prevent
it from entering. Much easier.
cheers
Alan J

ps. What is this 'rain' to which you refer ?
S.A. mythology has it that it is something like the light showers to which we are accustomed, only more intense.
Clearly the person who thought of that was off their rocker.....

Originally Posted by b.o.a.t.

Might be easier in that case to assist the water to leave quickly than prevent it from entering. Much easier.

And safer, if the flow is really eroding that much of the fill around the house.

I grew up in a house with similar issues. We eventually cut in a big drain uphill and re-graded everything between the drain and the house to redirect all the flow around, rather than through, the foundation. But in the decade it took us to save up the money for that job, we learned that we sustained far less damage by opening up some holes in preferred locations and directing the flow through the basement and out the garage. Yes, the basement was frequently damp. But it was not undermined. So the house didn't shift.

Trying to plug holes is treating symptoms, not causes. The water will either find another way in or it will erode the fill as it flows around or under. Or both. Relieve the pressure with controlled inlets until you can redirect the flow the right way.

Perzaktly !!
Although there won't be much fill around a properly built house in Sydney ironstone/sandstone country.
The bigger difficulty is excavating the footings to pour concrete around the rocks..

Originally Posted by b.o.a.t.

Although there won't be much fill around a properly built house in Sydney ironstone/sandstone country.

True. But the corner of the foundation only has to drop 1cm before you have cracks in the walls and your doors don't close properly anymore. And you start to have weird conversations with the wife about whether it makes more sense to hang the pictures level and have them look wrong next to the crooked window or hang them to match the crooked window and have them not level. Trust me, you don't want to have that conversation!

Originally Posted by paulie

And safer, if the flow is really eroding that much of the fill around the house.

I grew up in a house with similar issues. We eventually cut in a big drain uphill and re-graded everything between the drain and the house to redirect all the flow around, rather than through, the foundation. But in the decade it took us to save up the money for that job, we learned that we sustained far less damage by opening up some holes in preferred locations and directing the flow through the basement and out the garage. Yes, the basement was frequently damp. But it was not undermined. So the house didn't shift.

Trying to plug holes is treating symptoms, not causes. The water will either find another way in or it will erode the fill as it flows around or under. Or both. Relieve the pressure with controlled inlets until you can redirect the flow the right way.

Ahem ... When the builder who worked on the excavation and formation of the area under the house, he said that the first thing that we should do was to create a berm up the hill a bit, directing the water around and away from the house. He advised that simply using a couple of layers of bags filled with a cement/sand mix would probably be sufficient, but to try it and see. And of course, idiot here got stuck into plugging the leaks instead - in part because of structural deficiencies under the footings created by the excavation and the need to under-pin and lock them in place - and, um, "forgot" about the berm. Ahem, again . Mea culpa...

Looks as though I'm finally going to have to brave the tick colony that lives in the bracken up the hill (I'm highly allergic to the little eight-legged monsters) and get stuck into it. Or pay someone who isn't as tick-sensitive to do it.



The other thing that needs to be done is to seal the path at the back of the house and - ahem - install a drain along the uphill side thereof... As can be deduced, some (probably most) of the problems have been of my own making...I really should be ashamed of myself.

Originally Posted by b.o.a.t.

Meaning:
1. the water is entering the ground somewhere further uphill, & trickling flowing
down thru that awful bloory awful sandstone to fetch up against your wall/slab somewhere
under your existing ag drain ?
or
2. falling past the ag drain in the gravel beside the wall to bubble up again between wall & slab?

The second scenario is easier to fix, and doesn't need concrete... just the
profiling plus plastic sheeting I mentioned earlier.

Scenario 1 probably can't be fixed with concrete either. Not externally anyway.
Might be easier in that case to assist the water to leave quickly than prevent
it from entering. Much easier.
cheers
Alan J

ps. What is this 'rain' to which you refer ?
S.A. mythology has it that it is something like the light showers to which we are accustomed, only more intense.
Clearly the person who thought of that was off their rocker..... :D

It is likely to be both 1. & 2. I've cleaned off the chute quite thoroughly and started to clear the channel running along the wall/footings (again). There is buried 100 mm/4 " socked ag line running from the front of the hose down the hill that takes water that reaches it away. This works pretty well as there is always a swamp at the bottom for a while after it has rained.

One solution would be to demolish the whole joint and rebuild it properly, but that's not going to happen, at least by us.

I've been doodling around with a pencil trying to sketch the thing, but have got the proportions of crucial elements wrong, so will redo.

As to rain, I was beginning to think that it was something that I imagined, even here in Sydney - until the drought eased a bit. It's still not nearly as wet as it was when we first moved in, but it has got considerably damper than it has been in more recent times! Wish I could send some across to you - that way it might also fall on the Warragamba Dam catchment ;).

Cheers,
Alex.