New build level / grading issue

Hi Everyone,

I think I have a bit of a problem with the back yard of our completed new build property. I could really do with some advice please It's hard to explain, so please bear with me!

In short, the current ground level of the property is at least 20-25 cm below the intended level (the level of the rainwater drainage pipe grids installed by the builders confirms where I think the levels will be). This in itself is probably pretty standard. I'll have to get a lot of sand / top soil to grade the back yard to the correct level.

The problem I think I'll have is that when I keep the correct ground level throughout the garden the ground level will be piling up against our colorbond fence by at almost 15-20cm's. The fence (+-30m in length) is installed up on a retaining wall and I don't believe they are designed to have dirt / soil pushing up against them? Put in another way, it seems like the developers levelled our property ground level even with the top of the retaining walls and the house foundation got installed on top of that. Bringing the ground level up to suit the house it will be higher than the retaining walls and it will be pushing up against the colorbond fencing.

I hope that is clear enough to form and understanding of what I think could be a problem. To me it seems like either the land developers levelled / graded the property ground level to the wrong level, and / or the builders did not install the slab at the correct height.

Do any of you know who I should contact to get a professional opinion on this OR know what I should do? Any advice will be highly appreciated!!

 

Do you have a photo?

There will be a FFL (Finished Floor Level) nominated on your building permit which should be the height that the top of the slab is at.

It would be fairly normal for the developer to stipulate that levels are to remain what they are (usually in your land contract) and builders then put the slab on top of that. As the bricks go down to the bottom of the slab there shouldn't really be any need for you to increase the levels after so I'm perplexed what you mean by rainwater pipe grids.

Do you have a photo?

Do you mean the drains at the bottom of the downpipes? These are often raised a bit so that if you pave around them they are the same height as the paving.

The builder may also have allowed for the land to slope away from the house to the retaining wall. This is also quite normal - not all blocks are going to be perfectly flat from edge to edge but it probably would have shown so on your site survey plan.

 

I have a similar issue, the grade behind the house is lower on all sides and water will pool there until it hits the grate that is about 4 inches above ground level. The only thing I can think of is to build the land up and then grade it towards the grate.

 

Have the grate lowered by 75mm or pour a patio slab.

 

@waterbaby Presumably you should have paving or slab outside that sliding door, not bare earth. The builder will always leave those drains higher than they should be to accomodate future works.