Block paved drainage issues - Help needed

At a loss · Post: # 68374Post **At a loss** Sat Sep 17, 2011 12:50 pm

Hello,

I hope someone can help me, I have a block paved driveway long enough for one car. In between the front of the house (built circa 1920's) and the start of the paving is a 200mm wide channel of gravel. The driveway is flat and doesn't pool water, the problem is inside the house. There is mould inside the front room on an external wall just above the skirting (including in the corners where a disused chimney breast is). Recently mould developed on a pair of leather sandals my wife left in there (we don't use this room as we've been redecorating the house since we moved in). There are many other pairs of leather shoes in the room on which mould has not developed.

I suspect that this mould problem has something to do with the driveway as in the adjacent front room (which has grass outside) there is no problem.

More info: The room is North facing and has two external walls, which get battered by the wind and rain, there is a damp proof course (injections) which goes all the way round the house (but around the air-bricks) and seems to be working (green moss below but not above dpc). The mould on the walls is black spots, the mould on the sandals was white and furry. In the room there is a desk with books on it, no dampness on the books but we did have a bed in there which we have moved today but there was mould on the bottom of the mattress and on the wooden bed-slats.

Can anyone advise me what my options are? I am happy to provide more info as needed.

Many thanks,

John

Sat Sep 17, 2011 2:25 pm

try keeping a window open
mould generally thrives where there is poor ventilation
also could you post a picture of the drive and its relationship to the house
also of the level of the airbricks
lastly do y our gutters leak?
LLL

Carberry · Post: # 68380Post **Carberry** Sat Sep 17, 2011 3:59 pm

lutonlagerlout wrote:try keeping a window open

Second that. Solved all damp problems in my sisters house, she never opened the bloody windows.

local patios and driveway · Sat Sep 17, 2011 5:43 pm

i assume that your house being constructed in the 1920's will be a solid wall construction, have you done anything to insulate the walls or are they as they were when built? solid walls have a common issue when warm air touches the cold wall causing the black mold you mention. ventilation will help this somewhat. if this is the case the long term fix would be insulating the house at a cost of maybe 4k saving perhaps Â£200 year in heating bills anyway

it could also be likely that the height of the 'french' drain is too high in comparison to your damp course (picture would help at this point)

you could have a mains water leak under the floor.

the pointing and haunch on your chimney could have failed and water could capillarate down from there.

there are a lot of options

At a loss · Post: # 68384Post **At a loss** Sat Sep 17, 2011 6:38 pm

Hi all,

Thanks for the replies, after further investigation we have one under floor joist that is soaking wet underneath, it runs across the room and butts up to the chimney breast. We have lifted floorboards in other parts of the room and all other joists are dry but bricks (under dpc) are wet.

We have been advised to dig out the channel between house and drive to 18inches and put in better drainage (terram, stones, pipe, stones), but I'm not convinced this will solve the problem.

Any further advice? I can put pictures on tomorrow.

Thanks, John

local patios and driveway · Sat Sep 17, 2011 7:22 pm

for my money a linear drain leading to a soakaway or main drain (depending on your council and if they allow that) is the best option.

the wet floor joist shouldnt be wet as that should sit above the damp course unless the damp course has failed you need to find out how water is getting above the damp course.