damp issue in garage

[robjal123]

We have a garage building with some damp issues.

Some background:
Down one side on the outside there is raised beds that butt against the garage wall.

At one end there is a raised patio that is almost certainly above the level of any damp course (if there is one). Also at this end the guttering down pipe appears to take all the roof water into a soak away (i can't see the water draining into either the main drain or the old cess pit in the garden). Currently the soak away appears blocked as there is standing water in it - though this is only recently appeared.

At the patio/soakaway end there are damp spots (small circles) in a thick line that are above the patio level outside (which as mentioned above is above any damp proof line.

Question 1) Obviously i know i need to unblock the soak away. It drains under the raised patio to is it just a case of getting my hand down the drain and removing as much silt/debris as possible until the water drains away?

At the other end of the garage there is similar damp areas that start above the ground level.

Any ideas on how to proceed?

Question 2) How do I check to see if there is a damp proof course (sorry i'm a bit of a newbie). The whole building is rendered (an plastered on the inside) so i can't spy any dpc from the outside?

 

[flameport]

1. If this is a proper soakaway, there won't be a 'drain' to unblock.
If there is a drain hole, then it's not a soakaway - its a drain which is full of rubble and other mess.
A soakaway should also be several meters away from any building, so it has either been installed wrong, or it's actually a drain which is blocked up.

2. If there is a DPC, then the only way to locate it will be removing some of the render on the outside. However it shouldn't have render over it anyway.

The cause of the damp is almost certainly the blocked drain and the patio/ground outside being above the floor level of the garage.

 

[robjal123]

ok so i took the plastic grill off that the guttering downpipe empties over. after sticking my hand down it seems that there is something like this in there:

Untitled

• robjal123
• 28 Jul 2011
• 1

...except my one is terracotta. there was a bit of silt in the bottom which i fished out but there was no obvious blockage. I stuck a hosepipe down and into the horizontal part and manage to feed it in about 2-3 meters through a pipe (that runs under the patio) before it stopped going in. I left the hose in and turned the water on and it all seemed to go somewhere, ie it didn't back up in the u bend so it doesn't appear blocked.

 

[Static]

It may be that your soakaway is clogged or incorrectly size/built.. only way may be to dig it up and looksee..

 

[robjal123]

yup, think i'll have to invest in a lump hammer and decent chisel!