chased a line in concret down to wet earth, what now!!!

[mattadamson]

Hi All,

i have an old hoses with an extension. in the extension we are putting a shower (ground floor). i have cut a channel in the concrete for the drainage pipes but i have got down to earth with in a bout 7 inches (its a tiny extension only 1 meter by 4.

i noticed bits of clear plastic used as a DPM but now i have this channel how do i protect it against damp?
the garden is higher than the house by a foot and i expect the next time the garden gets sodden water may try and push up into my channel.

the channel is about 1.5 meters long with a cube (20cmx20cmx20cm ish) cut out at the end (for the shower drain to sit in).

help!! as the pipe goes in v soon and i want to make sure i protect my self as there will be a nice floor going down on top.


thanks chaps and chapettes.
Matt

 

[noseall]

insert a 'u' shaped bit of dpm into the trough and then concrete.
fit the dpm so that it goes half way up the sides of the existing concrete.

 

[mattadamson]

sorry for any double posting.

the forum said my post had not be accdepted at 1209 as i had posted a different question a couple of mins before and it told me to try again later,
i had assumed that it had not been accepted.

sorry Mr M

 

[mattadamson]

Hi noseall,

sorry for the double post, pure accident.

thanks for the advise, should i put the U shape DPM in place and lap the edges over so its almost an M shape or am i over worrying this damp???

 

[noseall]

so long as you do as i have described, in that none of your new concrete will be in contact with the earth, then you are taking reasonable steps to prevent damp.

the fact that no insulation is present means that there is a chance of condensation forming anyhow. this is only usually evident when lino or similar vinyl coverings prevent the surface of the concrete from being in contact with fresh air - and subsequently drying or evaporating the condensate naturally.