Front yard

[saveasteading]

weed membrane will do fine if you have some around. FYI The random fibres type is better than the woven in keeping everything out but it will be marginal for your circumstances.

[JohnBishop]

Hi again All,

  I continue to work on it and I realised I need to address the runoff rainwater on the side wall. There is tarmac and concrete between the houses and there is a bit of slope down towards my house what you can see on the picture.
Neighbour's DPC line is at least a foot above mine and rainwater that hits this hard surface between the buildings, I would say 15-20 sqm runs towards my wall and have nowhere to go.
Not sure why they did it this way but this whole bit next to the wall filled with gravel is contained, rainwater has nowhere to go without soaking the wall at the same time. You can see it being wet. I mean the gravel is no longer doing it's job as over the years mixed with soil, it holds moisture, some weeds pop up, also fat worms present in it tell me it's not gravel anymore.

While excavating this material I hit sand in few places but I still don't believe this is how the rainwater should be directed just next to the wall.
So I am thinking about extending this drainage to the existing one in the front yard. What do you think?
Orange on the picture is the existing soakaway that goes somewhere, the French drain with a 60mm perforated pipe (red on the picture) will go over that soakaway and next to the retaining wall

This is how it looks in relation to the schematic:

 

Just so you know this is not square but of this shape because of the concrete footing that redirects rainwater even closer to the wall.

 

We will see if I can dig out a hole under the concrete to run the pipe or will have to cut the concrete.

Edited May 26 by JohnBishop

[saveasteading]

7 hours ago, JohnBishop said:

the gravel is no longer doing it's job as over the years mixed with soil, it holds moisture, some weeds pop up, also fat worms present in it tell me it's not gravel anymore.

That is normal. remove the gravel then either wash it and reuse or replace it. The mucky gravel can be renamed 'free draining compost' as loved by succulents and herbs,

 

7 hours ago, JohnBishop said:

extending this drainage to the existing one in the front yard

Good idea. A small pipe will be enough to shift that small amount of water.  Make sure hat it can't work in reverse.

[JohnBishop]

while digging we come across some pipe, it's yellow, it's either water or gas. This looks like is going to be below a new layer of new material (MOT) 20cm MOT and 5cm grid with gravel.
Do we have to cover this pipe with anything to protect it from vibrations at this depth 25-30cm?

[ProDave]

Yellow is GAS.  (water is blue or older pipes black)  So get advice what to do with a GAS pipe.

[SimonD]

19 hours ago, JohnBishop said:

Do we have to cover this pipe with anything to protect it from vibrations at this depth 25-30cm?

 

Gas pipes need to be buried to at least 450mm under a driveway with light vehicular traffic. If you can't reach that depth then you need mechanical protection, like a concrete slab at least 100mm above the pipe. If you've got heavy vehicles, then you may need more depth, like 600mm. The pipework should be bedded in sand.

[JohnBishop]

36 minutes ago, SimonD said:

 

Gas pipes need to be buried to at least 450mm under a driveway with light vehicular traffic. If you can't reach that depth then you need mechanical protection, like a concrete slab at least 100mm above the pipe. If you've got heavy vehicles, then you may need more depth, like 600mm. The pipework should be bedded in sand.

Thanks SimonD
We are going to expose the pipe and see how deep it is. I think it slopes down towards the house so it could be between 35cm-60cm deep or it doesn't go parallel to the fence.
So I understand the idea is to bed the pipe in sand and cover with a slab, so we don't need to create a void, a bridge over it just make sure the pipe is 10cm in sand below the slab.

[JohnBishop]

it looks like the gas pipe had a bit of a slack on it and it waved up to about 35cm deep however once we exposed it we were able to lower it to 50cm. I slowly slopes down as it goes away from the public pavement. We also come across a water pipe (blue) at about 70cm.


Can someone recommend a suitable membrane to put to cover the driveway area before we put MOT aggregate? This is going to be a 20cm layer of mot then 5cm grid+gravel

[saveasteading]

47 minutes ago, JohnBishop said:

recommend a suitable membrane

As long as it is heavy duty, not just weed control, then almost any will do.

 

like this.https://www.toolstation.com/heavy-duty-landscape-fabric/p62380

 

if you need to lap it, then the lines show you how much.

 

Non- Woven membrane can be  stronger and doesn't get the little gaps between fibres that the above woven one does.  but the Toolstation one is for weeds only and I can imagine it tears easily.

[JohnBishop]

On 21/05/2024 at 22:47, Alan Ambrose said:

Only for v heavy duty or v long life.

I can see this installation guide for Ecogrid

https://ecogrid.co.uk/wp-content/uploads/EcoGrid-Gravel-Fill-Installation-Sheet.pdf

 

Did you work out the thickness of your subbase?

There is a table for "Field guidance for estimating sub-grade strengths".
I understand this is basically how much clay is in the soil what makes it soft or firm. In my case it's no clay at all but soil and pretty much all sand underneath.
I reckon the subbase supposed to between 200-100mm

I see some installers putting the grid directly onto the membrane without screed (sharp sand)
some don't even use the membrane:

 

Edited June 16 by JohnBishop

[saveasteading]

In approximate terms , the load of a wheel will spread at 45 degrees into the ground.  With dry hard earth you don't need much spread. With wet, weak earth you do.

 Plain grid will work a bit, but you really need sub- base.

The membrane isn't for strength but to keep the sub base separate from mud beneath. Or to keep the pretty stones in the grid above the lower layers, which isn't usually necessary.

 

[JohnBishop]

3 hours ago, saveasteading said:

In approximate terms , the load of a wheel will spread at 45 degrees into the ground.  With dry hard earth you don't need much spread. With wet, weak earth you do.

 Plain grid will work a bit, but you really need sub- base.

The membrane isn't for strength but to keep the sub base separate from mud beneath. Or to keep the pretty stones in the grid above the lower layers, which isn't usually necessary.

 

It looks like some of them use two membranes which makes sense to keep different materials separate. Nidagravel grids (not sure if all) have a built-in membrane into the grid.
I agree re sub-base. I am just not sure how deep 10, 15 or 20cm.

[JohnBishop]

I think I go between 10 to 15cm. I think this should be enough. I just have a hard time sourcing MOT Type 3 aggregate locally. They all have Type 1.

[saveasteading]

4 hours ago, JohnBishop said:

hard time sourcing MOT Type 3 aggregate

Type 1 will allow the rain to pass through, but doesn't have voids for storing it. Remind me if you were required to use type 3 or store water.

[JohnBishop]

13 minutes ago, saveasteading said:

Type 1 will allow the rain to pass through, but doesn't have voids for storing it. Remind me if you were required to use type 3 or store water.

Last time user Temp said "You might consider MOT type 3 hardcore instead of MOT Type 1. I believe Type 3 is water permeable where as some versions of Type 1 can be like concrete."

[saveasteading]

1 minute ago, JohnBishop said:

You might consider MOT type 3

OK. so it was a very good suggestion, but hard to find. Type 2 will drain a bit better but it ruts until covered over.

 

But who said you need highway quality sub-base? It isn't  a motorway.  My go-to is recycled road planings. ask a haulage company what they have.

[JohnBishop]

We built the retaining wall using dense hollow blocks. it's just two courses of blocks. One course of decorative brick will go on top.

Edited June 23 by JohnBishop

[JohnBishop]

We have removed some more material and we come across this oldschool soakaway. It's just in the middle of future driveway.

https://ibb.co/jrP2Gm7

The top of the pipe is about 45cm below the future grid surface.

 

What do you think I should do about it?
 

1. bury it as it was and cover with concrete slabs
2. build some concrete reinforcement around it

 

Edited July 5 by JohnBishop

[JohnBishop]

We built this proper soakaway but I think I can leave it empty inside, remove the rubble from inside as we cover it with a reinforced concrete plint cut in half.
Does that make sense to you?

[JohnBishop]

We opened the manhole and it looks like a sewer but it's not foul sewer, no smell, pretty dry inside could still be an abandoned sewer.
There is no indication of such sewer on any of the maps I looked including the online one. There isn't any sewer in the vicinity either but foul sewer at the back of the house.

[saveasteading]

8 hours ago, JohnBishop said:

it looks like a sewer but it's not foul sewer,

It looks like an unused sewer. well built and in good condition. Have you dared to examine the nature of the deposits?

If you project the pipe  directions you should find other manholes or likely connections to buildings. then you can pour water in and maybe see where it goes.

I would certainly not mess with it. Is it a problem in any way?

[Dave Jones]

On 29/07/2024 at 15:51, JohnBishop said:

We opened the manhole and it looks like a sewer but it's not foul sewer, no smell, pretty dry inside could still be an abandoned sewer.
There is no indication of such sewer on any of the maps I looked including the online one. There isn't any sewer in the vicinity either but foul sewer at the back of the house.

 

from condition looks like grey water. Can you put hosepipe into a downpipe connection and see ?

[JohnBishop]

On 20/05/2024 at 17:44, Alan Ambrose said:

If it helps any, these are the grids I'm looking at atm for heavy duty:

 

Option	Link	Size	Area	Volume	Depth		Weight	Cost
								ex VAT
		M			CM		M^-2	M^-2
Duratex	https://www.duratex.co.uk/permeable-paving-grids/173-heavy-duty-permeable-paving-grid-80mm-thick.html	.5x.5			8		12.8	36.00
Truckpave 80	https://grassmats.co.uk/product/truckpave-80/	.6x.4			8		12.8	41.46
Bodpave 85	https://grassmats.co.uk/product/bodpave-85/	1x1			8.5		6.2	16.69
Truckgrid	https://www.sure-green.com/truckgrid-max-heavy-duty-permeable-paver.html	.6x.4			8		9.0	46.01
Bodpave 40	https://grassmats.co.uk/product/bodpave-40-per-m2/	1x1			4		4.5	13.95
EcoGrid E50	https://ecotradecounter.co.uk/collections/permeable-paving-systems/products/the-indestructible-ground-reinforcement-grid-e50	.33 x .33			5		9.6	19.98

 

You might find some of these a bit too heavy duty, but I like to do these things only once. I also learned that the weight / m^2 is a good proxy for 'strength' and you can largely ignore the manufacturer's 'acceptable loading' figures. For heavy loading, the sharp nature of the gravel is important.

Hi again Alan,

  I reread your old post and I see this important note you made about using sharp gravel.
What classifies as sharp gravel?
I got for heavy duty 50mm grid.
I think about filling up the grid 2/3 with some cheaper material (sharp)
and some more decorative on top. What do you think?

[JohnMo]

13 minutes ago, JohnBishop said:

some more decorative on top

If by decorative you mean rounded stones, they provide zero load bearing and just slide about.

[JohnBishop]

19 hours ago, saveasteading said:

It looks like an unused sewer. well built and in good condition. Have you dared to examine the nature of the deposits?

If you project the pipe  directions you should find other manholes or likely connections to buildings. then you can pour water in and maybe see where it goes.

I would certainly not mess with it. Is it a problem in any way?

What do you mean by examining the deposits? Should I use my tongue? 😂

Its location is weird. It's few meters from a house and even further away from the street.
The manhole is at a bend.
It could be it connects with the manholes on the street (in green). Have a look at the attached map.
Orange is foul sewers at the back of the houses.

The concrete is too prominent to my liking but we won't demolish it. If unused I could convert it to a cellar or a one-man hurricane shelter or something.
However we will lower it by 2-3 courses of brick so it's more or less level with the ground.

Thanks for the suggestions, I definitely test with a bucket of water to a nearby manhole to determine the connections if any.
However it makes sense to examine the deposits first before I flush them away. LOL