Patio prone to ponding

[gazdavtom]

Hi,

I moved into a property about six months ago and it was noted on my survey that the rear patio did not appear to have any surface water drainage and could therefore be prone to ponding. Since living at the property I have observed that it does indeed pond in times of wet weather. Other than causing puddles and slippery surfaces are there any larger hazards I should be worried about by allowing this to continue? To give you a better picture, the patio runs adjacent to the back of the house, is constructed of large concrete slabs and measures approx 6 x 2.6m. The ponding mainly covers an area 1 x 3m and occurs about 1.5m from the back wall. I believe the surface water ultimately drains through the unpointed joints of the patio into clay soil underneath. I would greatly appreciate any advice on this.

[seanandruby]

Freeze thaw could have an effect on the wet surface and a really severe frost could go down between the joints and lift the flags etc: Might be best to incorporate some drainage and Also put a fall on the flags.

[gazdavtom]

Hi seanandruby,

Thanks for your advice, so not detrimental to the foundations of the house or anything like that? And what sort of drainage system would you recommend? Beyond the patio is a lawn but this is on a terrace with a dwarf/retaining wall dividing the two. Flower beds also flank each side as you look out from the house.

[gazdavtom]

Anyone out there who can advise re previous post?

[seanandruby]

Does your terrace wall have drainage behind and drain to a lower point. You could maybe get away with training to the turf area. An linear drain between turf and patio could be a goer but would need a gully and regular cleaning, also somewhere to drain to. Alternative work around would be here

[gazdavtom]

There may be something behind the wall but certainly not obvious. It does have weep holes along it.

[Tony McC]

A simple linear channel to collect the water (I'm assuming the patio falls toward the low wall) and then connect to existing SW or a soakaway (if poss)

[seanandruby]

Photo's talk. So you only have a crossfall, no fall whatsoever away from the house, or to the house? Can you lift some flags and do a percolation test to see how fast the water drains. It is a good sign that the water eventually goes, just needs to be quicker by way of added drainage. Once you know for sure you can then dig a soakaway. Give your lawn a good deep spiking to help it drain down into the soil.

[gazdavtom]

I have just been all over the patio with a level and in terms of falls it is all over the place to be honest. The edges of the flags aren't flush with the next so I'm guessing it will need to be relaid. I am hopeful that the garden is suitable for a soakaway. What about the weep holes in the wall between the patio and turf area? With a soakaway installed should I just allow these to work as normal?

[Tony McC]

It might be that you use a cannel at the foot of the wall to collect any water from the weepholes and direct it to a soakaway.