Bad patio

[Notch7]

Get your hosepipe out when its dry and see where the water goes.

Acos arent much money, the gravel top ones are a bit dearer. The complication is whether there is a convenient gulley. Do you have any house downpipes nearby that discharge into a gulley?

 

[Tony Hayes]

Only the one in the far left of the second picture.

Are there any cheaper alternatives? It is accumulating at the garage. To be fair I can now see that the lie in that area is not great. In the far corner the water does runaway from the house. But in the corner near the garage it is running back.

 

[Tony Hayes]

Ok. So I ran the test with the hose pipe. The water does run away from the wall however it does puddle a little, not to far from the wall.

The levels are a bit up and down on this patio. Would cementing the edges so water can' get down where the pebbles are help? Or would that make it worse? Another person has quoted 850.

 

[Doggit]

Still way too much. All it is, is cut the slabs with a 9" angle grinder that has a diamond blade. Dig out the gravel and any crap. Bed the drain channels in with a mortar mix, and then get the outlet into the drain with a bit of flaunching work. Post us a better picture of the surface water drain.

Have a look on youtube for fitting acco drain channels. Try this one.

 

[Tony Hayes]

Hi Doggit,

A picture of the downpipe is attached.

Would a gravel boarder work? How much would you say installing aco drains should be. I include a picture of the whole patio area.

 

[Doggit]

The gravel border fills with dirt, and becomes useless. If there's earth underneath the patio, then you cut a 4" channel around the house, and then dig down to the earth, and put in 1" stones. If it's clay, then you still need a channel somewhere to take away the water that collects down there.

The price for the job, is the one you manage to negotiate I'm afraid. If I told you £400 for a days work, and £150 for the materials; if you couldn't get anyone local to do it for that, then you'd be fuming, but 2 men should do that job in a day.

An angle grinder with a diamond blade will cost you about £60, you can get the drains from Wickes for £40 for 3mtrs, and you need sand and cement. Have a look on the internet to see how it's done, and have a go when the weather gets better.

 

[Tony Hayes]

Great advice. I have been thinking of doing it. Would I have to ensure that the acos, were angled correctly?

Would you just cut the slabs in place on the ground? The two people who have quoted both want to take these up and cut them.

 

[Doggit]

If you angle them to get the water to flow, then they'll end up dropping below the level of the patio; the water won't flow so well, but as long as you have a taught line to keep them as level as possible, then the water shouldn't sit in there very long. I cut the slabs whilst they were in place. Depending on how steady your hand is you can either mark them and take it carefully, or if you have a 4.5" grinder, you can hold a length of wood against slab, and then run the grinder alongside it.

 

[Tony Hayes]

Sounds like a great idea. So as long as they run parallel to the patio. Then the water should run away. Great. I have watched a few videos now so think I can do it.

A French drain is a no???

 

[Doggit]

Totally up to you. Cut the channel for the drain, and then asses the what's below it.

 

[Tony Hayes]

So you rate both equally?

 

[Doggit]

Yes, but things end up growing out of a french drain, and it needs ongoing maintenance, and can end up looking messier over time - but it's simpler.

 

[Notch7]

A French drain is gravel with a perforated pipe below, the disadvantage is as it silts up it will hold water against the house wall.

You could cut out out an acos width all the wall along, dig out a fair bit of soil and put in suitable gravel, leaving the level lower than now -that might be enough to resolve your problem.

Are you sure your bricks werent wet before? Rain water can get driven against a house wall and run down to the bottom as well as water running across a patio.

Think of a drain channel as being the same as a length of gutter, which is all it is. It will allow water to flow away, which is what you are trying to achieve

 

[Doggit]

Now are you suggesting just sitting the drains on the gravel bed Notch, as that would be a pretty easy DIY fix. You're right in your desription of a true French drain, but nowadays, it pretty much accepted as a gravel filled trench, except the gravel fills with earth, and the wet gravel lets the water soak across.

 

[Tony Hayes]

Brilliant. This is really helpful. To be fair. I am not sure if it was wet before as we only moved here in July. Pictures before the patio was laid and up to October time show it dry. Then the rain came!

Problem is I have nothing to compare it too. You can see from the pictures that it is an L shape at the point at which it is getting wet. It isn' wet along the whole length of the house. So it could be what you say Notch7, water driving into that corner, which is North facing and running down the wall. It struggles to dry as it never gets sunlight. Interesting the first slabs to dry are I that corner as the water runs off them and away.

It's difficult as 2 people have said that it is the patio, but they could be scouting for work. I am just worried as on the inside of the garage the bricks are wet (It's a single skin) again below the DPC. It makes me think that there is alot of water. However, doing the hose pipe test and using a spirit level shows that the water does run away from the wall. It feels difficult to get an accurate opinion. You guys have been incredibly helpful. Like I say one person quoted over a grand for drains! I don't know if he is just trying to make me panic so I part with a lot of cash!