Foundations

[ariel]

Hi guys! I need some advice from you, please.

I would like to build a retaining/feature wall between my home external wall and my neighbour's carport wall that is seating right on the boundary line.

The picture of the situation is the carport foundation spreading about 150mm outwards.
It is hanging above my side's ground floor level because dirt had to be dug out to achieve the home floor level that was required.

My question is if the excess foundation can be cut off (say 100mm) and if doing so that will not affect the carport's stability. . That would enable me to build a wall closer to the carport and provides some more room between the carport and my home which is at the moment only 800mm. (If I could I would insert a photo of the subject)

My intention would be to leave a gap wide enough between the retaining wall and the carport's that would be filled with concrete.

Thanking you in advance for any advice.

Ariel

[johnc]

Ariel,

I would start off with a chat to the neighbours before you get to carried away, they may not be all that happy about you chipping away at their footings. Incidently do they encroach over the boundry?, if they are on the neighbours side they are off limits, if on your side you may be entitled to give it a haircut. Interfering with foundations is not to be taken lightly and you really need to get someone to have a look and give a proper opinion, perhaps the local building inspector might give you a few ideas about your options.

John

[Sturdee]

My advice is that your action in excavating the ground level to below the foundation of the carport wall was already a big no no without consulting with your neighbour and getting an engineers report.

At least you should have shored up the foundation as you will be liable if something goes wrong.

BTW have you considered the possibility that your neighbour might well have claim to that bit of land that is covered by the garage foundation by way of adverse possession and that you were trespassing when digging out below it.

So go and do the proper thing and consult with your neighbour to see if he will contribute to an engineers report.


Peter.

[Exador]

Hi guys! I need some advice from you, please.

I would like to build a retaining/feature wall between my home external wall and my neighbour's carport wall that is seating right on the boundary line.

The picture of the situation is the carport foundation spreading about 150mm outwards.
It is hanging above my side's ground floor level because dirt had to be dug out to achieve the home floor level that was required.

My question is if the excess foundation can be cut off (say 100mm) and if doing so that will not affect the carport's stability.

How long has the footing been exposed? Who was responsible for exposing it? If your builder exposed it he may well have to bear some of the cost of remediation. Are you on Perth sand? What is the carport made of? What sort of retaining wall structure are you planning? Remember that the retaining wall will be supporting the building as well as the soil.My minimum recommendation would be to shore the footing IMMEDIATELY and then go seek guidance from a geotechnical engineer. Douglas Partners Pty Ltd are very good, as are Soil and Rock Engineering. As others have said, your neighbour may be willing to contribute, but I have to say I think you've left it too late to ask. If I was your neighbour, I'd say "fix it - NOW!".

That would enable me to build a wall closer to the carport and provides some more room between the carport and my home which is at the moment only 800mm. (If I could I would insert a photo of the subject)

My intention would be to leave a gap wide enough between the retaining wall and the carport's that would be filled with concrete.

Thanking you in advance for any advice.

Ariel

Your basic plan appears sound, but you MUST seek professional advice. If something goes wrong down the track you will be the one paying to fix it. If you are not on sand, your problem becomes all the worse. Either way, your retaining wall is going to be a lot more complex than you might think.