retaining wall for patio

[Jupiter01]

Hi, I have a patio area that needs to be raised to the same level as my bifold doors. I was planning to build a wall using blocks and then board this with appropriate timber to make it aesthetically pleasing.

Question, should I lay the blocks in regular fashion? I wasn't sure if a single block wall would be strong enough once hardcore is packed inside to bring the area to the correct level.

 

[noseall]

Looking at your photo says to me that you will likely be bringing the external GL up to at least the brick height, yes? This will leave just one block height once you consider that the patio will finish two courses down from DPC. A single skin of block could retain this sort of depth easily.

However, the fact that you will probably be building the patio before making up external ground levels and that you will be compacting the material within the patio area, suggests that you would be wise to double up the wall thickness. Make sure you fill the gap (20mm) between the block leaves also.

 

[Jupiter01]

Hi,
Many thanks for your response.
The GL is now set. We may need to alter slightly when some top soil and turf goes on but long story short, we had to go down to that level to have a reasonably flat garden bit at the same time maintain a subtle fall. I suspect that by the tine the turf and flower pots etc are out, the block will no longer be visible.
Returning to the patio, presumably you are suggesting that I finish up two rows below the dpc as this the allows me to lay a bed of sand/cement and then the slabs to ensure that the final finish is flush to DPC? Please clarify as this point was especially helpful.
On the blocks, can I use wall ties and build with a single leaf and yes I will be compacting hardcore in there, do I go with two leafs as you suggested or do I lay a single set of blocks in a flat fashion? One of my main concerns is the cost of blocks but clearly I don't want to compromise on the integrity of it either. The size of the patio is 2.2m x 4m. Thanks again

 

[Jupiter01]

I was wondering if someone can kindly glance over the above as I plan to work on this in a few days and would like to get it right. Thanks in advance

 

[Himaginn]

This will leave just one block height once you consider that the patio will finish two courses down from DPC.

Hi,
Returning to the patio, presumably you are suggesting that I finish up two rows below the dpc as this the allows me to lay a bed of sand/cement and then the slabs to ensure that the final finish is flush to DPC? Please clarify as this point was especially helpful.

I think noseall was suggesting your finished patio level should be two brick courses below your DPC. This is to prevent rain water splashing above your DPC.
A minimum of 150mm below DPC is required.

On the blocks, can I use wall ties and build with a single leaf

How could you use wall ties in a single leaf wall?

do I go with two leafs as you suggested or do I lay a single set of blocks in a flat fashion?

I would have thought either will do.
But I'm no pro'

 

[Jupiter01]

Thanks for the reply.
Is it not possible to be flush to DPC then? I thought I've seen plenty of pictures where there is little or no step from bifold door out to the patio? I will finish my patio lower if I must but aesthetically, it would have been nice to reduce the step as much as I can. I'd appreciate some clarity/confirmation on this.

On the comment about wall ties, I should have said wall starters. I was wondering if a single block leaf in the conventional manner would be sufficient if I tied it into the existing brick courses using a wall starter at these points. Hope that makes sense...

 

[Himaginn]

Thanks for the reply.
Is it not possible to be flush to DPC then? I thought I've seen plenty of pictures where there is little or no step from bifold door out to the patio? I will finish my patio lower if I must but aesthetically, it would have been nice to reduce the step as much as I can. I'd appreciate some clarity/confirmation on this.

http://www.pavingexpert.com/dpc01.htm

On the comment about wall ties, I should have said wall starters. I was wondering if a single block leaf in the conventional manner would be sufficient if I tied it into the existing brick courses using a wall starter at these points. Hope that makes sense...

That might prevent some lateral movement at the ends of the wall, but not in the rest of the wall.

 

[Jupiter01]

That link was very helpful. I will be going with a patio and DPC drop of 150mm and then slope the tiles as per advice. This will mean that I don't need a channel or a linear drain. Thanks again.