# Forum Home Renovation Sub Flooring  Sub floor drainage

## dabba

A recent buildings inspection report on a potential purchase highlighted an inadequate sub floor drainage.
in brief:
The ground floor has had recent flood damage and has fresh carpet laid.
The owner is currently in the process of digging a sub floor trench under the house connected to a drain in the brickwork going outside the house.
The builder has advised the the trench should be well below the ground (3m), currently the trench is higher than the ground floor(floor).
The builder has also advised that the sub floor drainage should not ideally be under the house but at the edges leading away from the house. Unfortunately the house sits on a plot containing solid rock and would most probably require major excavation.
Due to the rock, estimated cost around 50k! (as really unknown how difficult the digging will be).
Note-The ground floor walls also show high moisture levels on the internal walls as no proper damp proof membrane was installed on the outside, also the concrete driveway is higher than the floor in the ground floor room.
House is 40yrs old, 2storey,brick/timber frame, weatherboard clad. Structure-concrete infill slab and pier with strip footings. It also has some generic problems you would typically associate with a house of that age.
Im inclined to pull out as got a family on the way and have only really budgeted for renewing a bathroom or a kitchen, not major drainage works. 
Am I being slightly paranoid...?
Help please...!!

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## Bloss

Unless the price is reduced by $50k to account for the drainage needed stay away from it IMO. But then again you might say, if it has been lived in for 40 years by a number of owners how bad can it be? Actually pretty bad . . .

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## Uncle Bob

On the bright side the place sounds like it's got a decent foundation. That said, I reckon I'd keep looking.

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## Compleat Amateu

I have a house a bit like this, but older kids, more time and more cash.  Great fun, but I have all the tools and time. 
From what you have typed, family happening etc .... don't touch it.

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## barney118

I have similar issues with my house, I have excavated by hand 1m against the side wall of the brickwork (room is 1m below ground level) so far this has proved to be part of the issue with ground water seeping through the bricks. I plan on injecting some DPC (Tech-Dry - Rising Damp | Waterproofing | Water Repellent Sealers | Concrete Admixtures | Graffiti Removal) into the bricks and concrete, and then putting an infill slab in with a membrane under and going to go up the walls with it.

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## Kinroh

At least you can be certain that the foundations arnt going anywhere  :Biggrin:  Id stay well away from such a property, poor drainage results in a whole list of problems as you have already outlined + more.

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## dabba

Thanks all for the advice, said a big 'No'' to the .sub floor drainage' house and have now bought another 'hassle free' property instead. 
Note - Still scope to do some reno's on the new property so all good. 
Thanks again  :Smilie:

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## shauck

So, what did you buy? What will you be doing to it and/or what does it need doing? Got any pics yet?

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## dabba

> So, what did you buy? What will you be doing to it and/or what does it need doing? Got any pics yet?

  Very early days (move in next month)... 
But potential projects might be: 
New kitchen (original kitchen 60's).
roof void conversion to useable room.
garage is a bit weathered, could do with replacing, maybe provide plumbing/sewer/power for a granny flat type idea... (note- purely conceptual at this stage, and no realistic evaluation carried out of the cost..).
Bit of landscaping in the back yard - currently has a pergola and a raised grass area (which is completely shaded by a mini maple tree!). Not sure what's underneath the raised area though..?
A few new GPO's, maybe change the config of the lighting...
Also has potential for converting a section of the kitchen area to study/office space..? Sounds weird but will investigate further.. 
Damm I hate the tv series 'The Block', I get these sensational ideas about reno's and think I can pull them off...!!!

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## shauck

Sounds like a good project. Post in Go to whoa?

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## dabba

> Sounds like a good project. Post in Go to whoa?

  Will do. I'll appreciate all the advice/tips I can get...

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## shauck

And everyone loves watching a good reno in progress. Lots of pics especially

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