Rainwater pooling on indented flags - Is a skim the answer ?

[davowolf]

I wonder if there is any experience of this ? Short of replacing the flag would a solution be to put a skim of coloured mortar over the offending flag indentations ? Then hopefully with the level being slightly more raised, water would not collect and pool the way it is currently doing. If so what composition is best ? This is a newly laid patio. The first picture shows it very wet, the second when its almost dry.

/Users/peterdavies/Pictures/iPhoto Library/Originals/2010/19 Nov 2010/PB192482.JPG

/Users/peterdavies/Pictures/iPhoto Library/Originals/2010/20 Nov 2010/PB202484.JPG

[mickg]

the above links are not full URL's

to make it simple view the image in your browser and then copy and paste

[seanandruby]

change the flag.

[GB_Groundworks]

There not even urls they are the file paths on the hard drive of his Mac.

You nee to upload the photo to the net and post the links maybe with your mobile me or flickr or photoshack etc loads of free image hosts

[mickg]

link to photos

[mickg]

a few questions
it looks like the drainage channel is just higher than the side path flags on the corner of the house

am i right in thinking that the fall on the side path is from the corner of the house towards the timber structure after the side door as you can just see the brickwork joint appearing but its not visible on the corner of the house...thats if the existing house brickwork is level

does the drainage channel go across the rear of the house towards the conservatory ?

where is the outlet for the drainage channels ?

[davowolf]

The drainage channel is OK I think Mick - the plastic cover was a bit high after the regular maintenance it needs - I just trod it back in level.

I believe the fall was meant to be away from the timber tool shed towards the drainage channel but I think it ended up more or less level along the side of the house but falling away from the house perpendicular to it.

The drainage channel only extends about 1m towards the conservatory. The main sewage outlet was too close to the surface, otherwise the original plan was to extend all along that back wall to allow drainage for the patio.

Those channels open into a common opening to a soakaway with the roof drainage downpipe which is open above a semi-circular cap into the hole. This used to be a closed system before the patio work was carried out.

If I understand your drift, you're thinking 'is this a drainage problem or one arising from the slab indents alone' ? mmmm....see what you mean....I did think it was the flag indents but you may have a point.

If it is the flag indents, the question would be to change the flag or use a skim. I'm not sure whether such a skim is normal practice for such a problem but if it is, what sort of compound would best be used ?

[mickg]

damage limitation advice, not the correct way but.............

without seeing the job on site and checking for the fall on the flags there are 3 ways to try and rectify the paving as adding anything to the surface of the paving won't look nice for sure and won't last either

1....take up the low area and re bed these flag
the down side to this is it looks from the photos very tight on fall so you could end up pushing the water to another area and still have the puddles

2.. drop the height of the drainage channel and the height of the flags holding water from nothing along the straight line you have in the paving from the back door to where the green bin is to the new height of the channel once its set to the lower level, this may only be 10mm or what ever is needed to give the flags enough fall to disperse the water

you may always have some water in the bottom of the channel but at least the path is draining correctly, water finds its own level anyway so if the channel has got slight back fall (even though its not the correct way) it can't build up and overflow back onto the flags unless the outlet becomes blocked but at least your path is clear of puddles

3...take up most of the flags to the side area and relay giving path a fall of at least 1:60 1:80 minimum towards the drainage channel
a lot more work involved but this is how it should of been laid in the first place

oh and one more
4.....live with it

[davowolf]

Thanks Mick ....and for doing the pictures...lots of food for thought here.....I'll let you know of any progress.....if any.....

[lutonlagerlout]

imho 4 maybe the path of least resistance :;):
LLL