How high can lawn be against house?

[Drish]

Hi all,

I’m building a new house in Perth, and it’s a double-brick home. I’m keen to do my own landscaping; however, I’m a bit confused about how high I can bring the lawn sand.

I’ve checked with ChatGPT, which suggests the lawn level should be 75–100 mm below the bottom of the weep holes. However, at that level I reach the concrete footing (maybe overpour).  I am planning to put a Gravel strip next to the brickwork, however I am unsure if I need to cut the concrete overpour to make it sit cleanly. 

I’m looking for tips or guidance from anyone who’s been through this.

Thanks in advance.

.

[MitchellMc]

Welcome to the Bunnings Workshop community @Drish. It's amazing to have you join us, and many thanks for your question about laying a lawn.

Yes, it’s important to keep a clear gap beneath the weep holes. As a general rule, finished ground levels, whether that’s soil, sand, mulch or gravel, should not be brought up to or above the bottom course of bricks. The damp proof course sits just above this level and is designed to stop moisture tracking up into the wall, so covering that area can allow moisture to bridge the DPC and cause long-term issues.

In practice, this means you should maintain a visible clearance below the weep holes, commonly around 75 to 100 mm. If you are already hitting the concrete overpour at that level, that’s quite common on new builds. It’s not good practice to simply build up against the brickwork, even with gravel, so cutting back the concrete overpour is often the correct approach to allow the gravel strip to sit lower and maintain that clear zone beneath the weep holes. This also helps with drainage and keeps the wall able to breathe.

So your plan to include a gravel strip is a good one, but it does need to be set at the right height. Keeping soil and landscaping materials away from the lower bricks and below the weep line is both good building practice and a building code requirement, and doing it right now will save you moisture and durability problems down the track.

To remove the overpour, you might be able to knock some of it off with a mini sledge, but an angle grinder with a masonry blade is likely the most proficient method. Remember to wear PPE, including a dust mask and safety glasses.

There’s also an earthing wire and electrical conduit running through or near the concrete overpour in that area, so if you do decide to cut it back you need to be very careful not to damage them. If you’re unsure where they run or how to protect them during the work, it’s a good idea to enlist the services of a licensed electrician before proceeding. Taking that extra step will help ensure the work is done safely and avoids creating an electrical issue while you’re trying to solve a drainage and moisture one.

Please let me know if you have any questions.

Mitchell
 

[Drish]

Thank you Mitchell, is there a way for me to know the extent to which I can cut the overpour and not cut any of the footing concrete inadvertently. I have attached the footing and brick relationship as per the engineering drawing

 

[JacobZ]

Hi @Drish,

The overpour, if it is indeed an overpour, is not going to be shown on the plans as it is not a planned part of the foundation. Unfortunately, this means we won't be able to use them in this scenario without further investigation.

If you wanted to confirm that it is indeed an overpour and see the extent of it, you would have to dig out the soil to visually inspect it.

If you were to do this, you should be safe and contact Before You Dig Australia (BYDA) to confirm the location of your services before breaking ground.

Once you can visually see what the slab edge looks like, you will have a much better picture of what can and can't be removed. At this stage, you could upload a photo of the slab edge for us to have a look at and offer guidance, but without seeing the slab edge, we would unfortunately be playing a guessing game.

Let me know what you think.

Jacob