Patio Drainage - Suggestions Please

[Willmott85]

Evening all. I'm hoping the community can offer me some advice, and maybe an alternative, to a patio drainage problem that I am going round and round in my head on how best to solve.

I am re-landscaping the garden and as part of the work re-modelling an old decking area, and introducing a 3 tiered patio and decking mix, as shown below. The reason I'm adding in the middle decking is just to break up such a large patio area and create some contrast.

The problem I am trying to solve, is finding the best solution for the drainage, to set the fall of the patio.

Points to note that are not shown in the attached images.

1) There is a grassed garden extending on from the patio/decking area.
2) In due course (likely next year) an outdoor undercover eating area will be built, represented by the dashed area in the 3rd image.
3) Slabs are likely to be 800x400 Bradstone Romeli porcelain.
4) I'm an engineer by day, but keen, and pretty handy on the tools. Downside is I overthink things!

In terms of drainage, two of the areas are easy:

1) The lower patio (dark blue) can drain off straight into the garden, which is beyond.
2) The decking can drain into a existing drainage that will be under the decking itself.

It is the upper patio area that I am unsure of how best to manage. As there will be steps around 2 of the edges, I feel it is best to either drain towards the steps, and have an ACO drain at the start of the steps, or the inverse and drain away from the steps to the house/boundary wall, and have the ACO drain along those edges.

I do not think it is wise to have a fall along the length of the steps, purely from a build perspective. But maybe I am wrong on this?

Whilst the drainage solution proposed in the image seems sensible, I am not sure how the finished result will be with a mitre joint in the patio.
If you were posed with this problem, what would your proposed drainage solution, and fall direction, be?

The fact that a large portion of the upper area is likely to be covered makes me think I don't need to worry about drainage on that portion, as water will be minimal. However, if built sometime next year, that would be ~12 months of no cover, and potential problems?

Any help or advice you can give would be greatly received.

 

[blup]

Evening all. I'm hoping the community can offer me some advice, and maybe an alternative, to a patio drainage problem that I am going round and round in my head on how best to solve.

I am re-landscaping the garden and as part of the work re-modelling an old decking area, and introducing a 3 tiered patio and decking mix, as shown below. The reason I'm adding in the middle decking is just to break up such a large patio area and create some contrast.

The problem I am trying to solve, is finding the best solution for the drainage, to set the fall of the patio.

Points to note that are not shown in the attached images.

1) There is a grassed garden extending on from the patio/decking area.
2) In due course (likely next year) an outdoor undercover eating area will be built, represented by the dashed area in the 3rd image.
3) Slabs are likely to be 800x400 Bradstone Romeli porcelain.
4) I'm an engineer by day, but keen, and pretty handy on the tools. Downside is I overthink things!

In terms of drainage, two of the areas are easy:

1) The lower patio (dark blue) can drain off straight into the garden, which is beyond.
2) The decking can drain into a existing drainage that will be under the decking itself.

It is the upper patio area that I am unsure of how best to manage. As there will be steps around 2 of the edges, I feel it is best to either drain towards the steps, and have an ACO drain at the start of the steps, or the inverse and drain away from the steps to the house/boundary wall, and have the ACO drain along those edges.

I do not think it is wise to have a fall along the length of the steps, purely from a build perspective. But maybe I am wrong on this?

Whilst the drainage solution proposed in the image seems sensible, I am not sure how the finished result will be with a mitre joint in the patio.
If you were posed with this problem, what would your proposed drainage solution, and fall direction, be?

The fact that a large portion of the upper area is likely to be covered makes me think I don't need to worry about drainage on that portion, as water will be minimal. However, if built sometime next year, that would be ~12 months of no cover, and potential problems?

Any help or advice you can give would be greatly received.

I would make slab the middle area and rely on the fall to drain off. Otherwise ACO’s as suggested to minimise discolouration/rotting of the decking. But you can probably get away with it if it is to be covered and properly guttered ie no overspill from rain at the very edges that need protection

On the design, I can see how you have approached it as an engineering solution. An acquaintance employed a similar solution, and young kids and well oiled guests have to be very careful moving about at bbq’s because of the trip and fall hazard from the proximity of the steps and relatively narrow patio sections like yours. I would design a single flat patio with steps at the side(s) and an enclosure around the edges. This also maximises the use of the space.

 

[Willmott85]

I would make slab the middle area and rely on the fall to drain off. Otherwise ACO’s as suggested to minimise discolouration/rotting of the decking. But you can probably get away with it if it is to be covered and properly guttered ie no overspill from rain at the very edges that need protection

On the design, I can see how you have approached it as an engineering solution. An acquaintance employed a similar solution, and young kids and well oiled guests have to be very careful moving about at bbq’s because of the trip and fall hazard from the proximity of the steps and relatively narrow patio sections like yours. I would design a single flat patio with steps at the side(s) and an enclosure around the edges. This also maximises the use of the space.

Thanks for your reply.

I'm not keen on slabbing the middle area. Will just be too much I think. Unless it was done in a different type of slab. Either way the drainage problem for the upper section remains the same.

As you say if covered then I will make sure it has adequate guttering, but that will only be for the upper section closest to the house. The upper section running away from the house, along the boundary wall, will still need some drainage surely?

Regarding the design, it is already a 2 tiered layout at present. To make it one level section, would be 10's of tons of hardcore. Coupled with the fact I think just one large flat area will be too overpowering, i'm not keen on that.

I think the images do not show the scale properly. I have marked it it out already with line paint and looks nice and spacey. The 'narrow' section of upper patio running along the boundary wall is nearly 3m wide. Thats pretty spacious.

I've been through the idea of brick/walled planters along the edges where there are not steps, and partner is not keen. We will just be having lots and lots of large pots/planters, so they will act as a form of barrier. Not keen on a formal barrier, glass or otherwise.