How to pave path and alfresco?

[whopper]

Hey Bunnings Crew,

I’m looking to begin paving a path and small alfresco area on my new build. Just wanted to check to see I’ve got my heights right before I put down my DPC and then go ahead with my roadbase.

How it stands, I’ve dug out a depth of 200mm to allow for the following:

-DPC

-75mm Road Base

-30mm Bedding Sand

-40mm thick paver

-50mm breathing space

The DPC should come up to roughly 150mm after it has been trimmed which should go about my pavers but allow for the breathing space in the foundation.

I’m finding the paperwork I’ve been given not ultra clear but to my current interpretation this is what I’ve got planned at this stage.

How does this all look or am I will I need to get back on the shovel?

My only other question is around the paving of the alfresco area. I’ll be paving on top of the slab so the depth is a lot lower. Current plan here is to still lay the DPC and then just put down less road base as the slab is already solid? I’ve got about 150mm of working space here so working on my above calculations it’d be 25mm of road base through the alfresco. 

All responses are appreciated, cheers!

[MitchellMc]

Welcome to the Bunnings Workshop community @whopper. It's fantastic to have you join us, and many thanks for your question about paving.

For a standard paved path, you usually just need a compacted road base, bedding sand, and then your pavers on top. A DPC isn’t normally required for paving, because it can actually trap moisture within the base layers rather than letting it drain naturally.

Height-wise, 75 mm of compacted road base, 30 mm of bedding sand, and your 40 mm pavers is fine. The 50 mm “breathing space” you’ve allowed, I’m not entirely sure what that’s intended for. If you could clarify, that would help. Here's a helpful guide: How to lay paving for a path.

For your alfresco over the existing concrete slab, you generally wouldn’t need a road base at all. The slab itself is already a solid base, so you could either lay your pavers directly onto a thin mortar bed or use a suitable adhesive system for pavers over concrete. Again, the DPC isn’t really needed here either.

In summary, the path looks fine with the compacted road base and bedding sand, but the DPC in both areas seems unnecessary, and over the concrete slab, consider embedding your pavers in mortar instead of adding road base.

Please let me know if you have any questions.

Mitchell
 

[whopper]

Hey @MitchellMc thanks for the response. I have viewed the guide and will definitely be using it as support.

Apologies for being a little unclear around the usage of the DPC. The paper work from the builder recommends using DPC between the slab/foundation and pavers. As your recommendation, my current plan was to have a clear path between pavers and base layer so that moisture can naturally drain. It was also the builders recommendation to have 50mm of slab exposure to allow the concrete to breath.

It is really quite confusing as my internet searches have provided a range of different responses.

[MitchellMc]

Probably best to follow the advice of the builder @whopper. However, I'm unsure what a DPC over the concrete would achieve. Typically, it could be left exposed to the elements, and you are just adding another layer of mortar and pavers over it. It's no more exposed due to that. I'm not aware of the specific elements of your project, so it might be best to clarify the need for the DPC with the builder or take their advice and include one.

Mitchell