New patio questions

[lfc84]

Hi

I'm doing a new patio. The old one was pre cast concrete slabs on a sand / gravel mix. The drainage was poor. We've taken up the old slabs.

Now doing the preparation for the new patio. There will be a wall on two side. You can see the start of the two walls in the photo below.

We've had some heavy rain. This is the result....

https://photos.app.goo.gl/Mt9BwUvkg75NTrgP2

I think we should stop now and remove all of the current base and take it back to soil. Removing the sand and sorting the drainage. Presume people here agree ! Also, should we build the 2nd wall now or wait until after the patio is complete ?

 

[LawnMower]

Start with your drainage.
If you have drains that take storm water away I would tap into them, you could put a soakaway in but these often fail in heavy rain and especially if your ground is clay and you have a high water table. Failing that build a sump hole and insert a pump with a float valve https://www.toolstation.com/shop/Po...220/Draper+25360+750W+Dirty+Water+Pump/p60074

Once you have sorted drainage you can either dig footings for new walls or lay slabs (the edge slabs only) on a reinforced base of concrete (dig 200mm 100mm of compact hardcore then 100 mm concrete with steel rods running through it all) which will allow you to build straight off the slabs afterwards.

 

[r896neo]

Patio drainage is run off. You don't improve drainage of the ground under paving? You capture the water and send it to somewhere.

You would normally build walls first. Never put hardcore under a wall footing.

Your new walls will be retaining walls presumably so you need drainage and weep holes behind them.

Hard to give specific advice without a better overview of your plans and the wider area.

 

[lfc84]

Thanks for the replies