The Brew Cabin

Posted: **Wed Oct 08, 2008 12:41 am**

Hi all,

First of all I got to say that this site is fantastic, however with so much information I am getting confused the more I read various pages not to mention other sites and the advice from various contractors all of whom say different things. So some help on here would be most appreciated.

The plan is to put down Drivesett Duo with aco channel drain near the front of the house.

On excavation of the front drive the builder has come across very soggy sub soil near the house end of the drive and suggest that we put hardcore then concrete down as a result and then lay Marshalls Drivesett Duo blocks on a bed of dry sand / cement mix.

Is this the right way to lay these 50mm blocks? Do I have to worry about drainage of the bedding layer if the above bedding method was used as mentioned?

Or should be it just dry sharp sand on thick hardcore?

F.Y.I Hardcore is going to be the old crazy paving plus grit sand and then more hardcore. with compaction.

If blocks are laid this ay will they take longer to dry out in wet spells.??

Also we have damp walls under both windows.. any advice on this would be most appreciated. Do I have to remove the render up until the DPC and apply some kind of liquid damp proof membrane ? and then render again with somekind of waterproofer/retard mix in the render? whats the best thing to do.

The black strip you see painted under the window in my opinion does not do anything, its seems more cosmetic then anything at present .

Thanks in advance

Stephen

Drive Picture A

Drive Picture B

Posted: **Wed Oct 08, 2008 5:51 am**

it depends if you are going for rigid, or flexible paving. i would dig out as much of the mud as you can, remove the water with an old tin can, surround the gas in sand then place dtp1. the damp under the window must be getting in around the frame so check that area and where the guttering is, or internal pipework to see if that is leeking.

Posted: **Wed Oct 08, 2008 8:38 am**

this is what i'd do,

dig it out and get rid of the bad ground till you hit firm solid ground, terram or another geotextile and then fill back upto level with dtp1 in layers compacting them as you go, depending on what your using we use 2 ton roller so we do 150mm-200mm layers. with a whacker i'd come up in 100mm layers and give them a good whackering. you cant just pile it up and whacker through like 400mm end up with soft spots.

my 2 pence

Posted: **Wed Oct 08, 2008 1:16 pm**

Thanks for your post

I not sure what the best option to go for solid or flexible with these blocks as i am getting conflicting opinons.

I want to do it right. My worry is drainage of the bedding layer if I go for solid

however on flexible he suggest to use dray sand and cement for the bedding layer ? is this correct ? most sasys it should be only sand.

Posted: **Wed Oct 08, 2008 7:04 pm**

DIYStephen wrote:however on flexible he suggest to use dray sand and cement for the bedding layer ? is this correct ? most sasys it should be only sand.

for flexi paving just sand for the bedding layer, cement will have an adverse effect

Posted: **Wed Oct 08, 2008 10:31 pm**

The question I would be asking is why the ground is waterlogged. it looks like a gley soil which is permanently wet clay, it may be coincidence but the water seems to follow the line of the gas pipe, maybe they damaged a drain when excavating the trench. Does the water have an odour

Posted: **Thu Oct 09, 2008 4:48 am**

slimdotjim wrote:The question I would be asking is why the ground is waterlogged. it looks like a gley soil which is permanently wet clay, it may be coincidence but the water seems to follow the line of the gas pipe, maybe they damaged a drain when excavating the trench. Does the water have an odour

could be a coicidence but maybe it could be to do with the rain we have had :;):

Posted: **Thu Oct 09, 2008 8:21 am**

DIYStephen wrote:Thanks for your post

I not sure what the best option to go for solid or flexible with these blocks as i am getting conflicting opinons.

I want to do it right. My worry is drainage of the bedding layer if I go for solid

however on flexible he suggest to use dray sand and cement for the bedding layer ? is this correct ? most sasys it should be only sand.

Flexible should be cheaper and at least as long lasting. It's more forgiving as well.

I'm sick to death of contractors advocating cement in the bedding. When they say it's better, they mean that it's better for them - you don't need to get the sub-base as even or the screed consistent if you add cement - the blocks go down faster and you get a good, quick effect. The problems come later when the contractor's long gone.

Posted: **Thu Oct 09, 2008 9:11 am**

slimdotjim wrote:The question I would be asking is why the ground is waterlogged. it looks like a gley soil which is permanently wet clay, it may be coincidence but the water seems to follow the line of the gas pipe, maybe they damaged a drain when excavating the trench. Does the water have an odour

its likely to be water logged as it disturbed ground, i.e from when they put the new gas main in and back filled with the outcomings. acting like a drain as its the lowest point.

Posted: **Thu Oct 09, 2008 10:34 pm**

Yeah that makes sense GB, It was just the colour of the soil having that bluey grey look, which is usually an indication of long term saturation.

Posted: **Fri Oct 10, 2008 8:49 pm**

Posts and emails such as this come in all too often and there are certain words and phrases that trigger panic in my breast. Words such as "builder", "hardcore of crazy paving", and worst of all "sand and cement bedding". Put all three together and my cowboy alarm starts going ring-a-ding-ding at full volume!

The Brew Cabin

Driveway layers for marshalls drivesett duo blocks - Driveway advice with pictures included