# Concrete slab patio - drainage



## rustyfisher (Apr 21, 2011)

So . . . I'm here, even after reading all the various concrete slab patio problems, yet still without a solution.

We just bought a house within the last year, which was built in 1960. At that time there was an in-ground pool built in the back yard and a 12'x24' patio(with awning) adjacent to the attached garage (also slab). A well underneath the patio slab was also built, with the pump and tank just inside the garage. A 2'x3' hole in the concrete exists as apparent access to the well below (as informed by the original owner), which is covered with a heavy duty steel plate. Note we have a crawl space under the house.

About 10 years prior to our moving in, the pool was decomissioned and removed, and the water lines running to the well pump (for filling the pool) were capped.

The slab has a crack along the width, across the center of the hole, resulting in poor drainage towards the middle (in the direction of the hole) as well as towards the house. Before I go building a deck on top I would like to deal with the drainage issue, especially in the absence of the awning.

I've recently had dreams of a little backyard rehab. I've removed the rusted awning, with a plan to lay down (an easy-painless-very basic-do in one day) wood deck. My deck idea was some what simple; 1x4 sleepers set 16" on center - perpendicular to the house and cedar deck boards parallel to the house.

I had purchased some self-leveling cement in the hopes of atleast creating a flat surface if not a slight slope towards the yard. I realize the problems creating the original crack will probably show through to any newly poured concrete if not properly corrected. 

So - here are my questions. Mind you I am trying to avoid more expensive alternatives, which include; mud jacking, and tearing down the slab to rebuild.

1. How can I correct the drainage problem with the slab? Can this be done DIY at all.
2. I have to keep access to the whole in the slab for well purposes. How do I cover the access hole (2' wide, across 1+ sleeper) to avoid to much water flowing in, while maintaining proper spacing of the sleeper.
3.Since the awning has only been recently removed, I do not know the potential drainage problems. Is it worth building a simple deck and watching for any possible water related problems?

It's supposed to rain here for the next 4 days and we have very overall poor draining soil, so we will see what happens before I get back to working on this project. I don't mind accessing the slab hole by removing a sleeper and several deck boards if the necessity deems so.

Any advice would be greatly appreciated. So much for the easy project here...


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## inspectorD (Apr 22, 2011)

Ok, this may hurt a bit,
I always ask folks, if you do not have the funds to do it right the first time, do you have the funds and the time to fix it the second time?

water issues around the home are the biggest problems you can face. I'm sure this is nothing new to you, but I just hate to see folks waste time and $$ on a dream I know from experience will have problems after you build it.
 If you have frost, installing a deck on a slab is a bad idea, it will only continue to move and fall apart.

To do this right, 
Remove the slab and fix the grade below a deck with piers and a wood structure underneath.
Or, Mudjack the existing concrete and install brick or patio pavers over the top of the slab. Sometimes this is an easier solution.No deck to stain or protect, easily removable to gain access to the pit, and water drains away.
And patios are not a TAXABLE property structure, and need no permits like decks do.
Hope this helps,


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## joecaption (Apr 23, 2011)

1 X 4's will just rot out, if a wooden deck has no air flow under it you will be fighting rot and mold from day one.
Have you at least installed a gutter over that area?


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## rustyfisher (Apr 24, 2011)

Well... that puts me in more of a quandry. We could mudjack the cement but then are still left with a concrete slab we can't deck over (not enough drop from the back door), and really can't lay down pavers (wont work real well with the current well hole). My current thought is to rip up the concrete and lay down pagers directly in front of the door on sand then raise a floating deck with a step. 

Let know if there is any other advantage to keeping the concrete.


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## inspectorD (Apr 25, 2011)

There really are no advantages of keeping the old concrete. I does remove any water near the foundation a little faster, but it is expensive to keep it sloped away, and harder to work with. 
Sloped Soil is a DIY project that also lets you change the grade (slope) as you need to.
And a cover for your well does not need to be paver. You can build a stationary Bar or table, even a wishing well. Just use a steel plate, or a small wooden cover out of Pressure treated plywood. Then cover it with a piece of furniture.
Or build your deck as you suggested, only you know the reality of what will actually work the best. 
Hope this helps.


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