Help: Pool deck causing moisture issues in house

poolnovice1

Bronze Supporter
May 11, 2018
95
Houston
I hope I posted in the right forum (mods feel free to move if not).

We bought the house in 2014. The pool/spa and deck were built in the early 2000s.

We've been dealing with an extremely frustrating problem. Water/moisture is getting under the floors of the house in the rooms adjacent to the deck. Our wood floors in these areas have moisture damage. We've replaced the damaged areas twice and now we will tear out the floors and put in tile.

But onto resolving the source of the moisture...

There are 5 drains throughout the deck which are all functioning.

However, from the right side (left in picture) to the middle of the house, the concrete is poured at a level that is at the top of the foundation. I believe this is allowing any water that misses the drains to seep into the brick and weep holes. The deck then slopes to the left the house (right in picture) and towards the front of the garage. I guess the idea was to get water to flow towards the driveway.

We installed new 6" roof gutters which help quite a bit but it has not resolved the problem.

I can think of three ways to fix this:
1. Tear out 10" of deck along the back of house and put in gravel (no drain).
2. Tear out 10" of deck along the back of the house and put in a channel drain.
3. Tear out a larger portion of the deck (see drawing #2) and put in grass.

#1 would be the least expensive but would it even work? Would #2 hold in a heavy storm or hurricane? #3 seems like a surefire solution but I'm having a hard time figuring out how to make it look good.

Any thoughts, suggestion, or ideas will be appreciated. Thank you.
 

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Bperry

Gold Supporter
Aug 20, 2020
874
Knoxville, TN
Pool Size
27000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
CircuPool RJ-60
I hope I posted in the right forum (mods feel free to move if not).

We bought the house in 2014. The pool/spa and deck were built in the early 2000s.

We've been dealing with an extremely frustrating problem. Water/moisture is getting under the floors of the house in the rooms adjacent to the deck. Our wood floors in these areas have moisture damage. We've replaced the damaged areas twice and now we will tear out the floors and put in tile.

But onto resolving the source of the moisture...

There are 5 drains throughout the deck which are all functioning.

However, from the right side (left in picture) to the middle of the house, the concrete is poured at a level that is at the top of the foundation. I believe this is allowing any water that misses the drains to seep into the brick and weep holes. The deck then slopes to the left the house (right in picture) and towards the front of the garage. I guess the idea was to get water to flow towards the driveway.

We installed new 6" roof gutters which help quite a bit but it has not resolved the problem.

I can think of three ways to fix this:
1. Tear out 10" of deck along the back of house and put in gravel (no drain).
2. Tear out 10" of deck along the back of the house and put in a channel drain.
3. Tear out a larger portion of the deck (see drawing #2) and put in grass.

#1 would be the least expensive but would it even work? Would #2 hold in a heavy storm or hurricane? #3 seems like a surefire solution but I'm having a hard time figuring out how to make it look good.

Any thoughts, suggestion, or ideas will be appreciated. Thank you.
If water is actually getting in where you think it is, channeling it away is the best solution. Putting in gravel seems like it’ll just hold more water at that 10” channel unless it’s slopes to allow it to drain out to a lower spot. If you were going to fill with gravel, adding a french drain pipe on the same spot wouldn’t be much more expensive. I’m also not sure grass does a lot for you unless you change the slope of the grass area to slope away from the house.
 
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superuser

Well-known member
Nov 16, 2020
195
Spring, TX
This is Houston, it's possible things have moved around and the house is now lower in relation to the deck from where it was originally constructed. It may be worth calling out a foundation company to put a water level on your slab and see if your house shows to be down on the pool side. Not that it would make the resolution any better, because if that's the case you'd need to break up the deck anyway to have the slab piered.
 
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JamesW

TFP Expert
Mar 2, 2011
27,709
It seems odd that the pool is so high, which makes me think that maybe the pool floated.

I would put in at least one dry well so that you can monitor the ground water and pump it out as needed.




 

poolnovice1

Bronze Supporter
May 11, 2018
95
Houston
If water is actually getting in where you think it is, channeling it away is the best solution. Putting in gravel seems like it’ll just hold more water at that 10” channel unless it’s slopes to allow it to drain out to a lower spot. If you were going to fill with gravel, adding a french drain pipe on the same spot wouldn’t be much more expensive. I’m also not sure grass doesn’t a lot for you unless you change the slope of the grass area to slope away from the house.

I'm not 100% sure if water is getting in from there because the moisture damage on the floors are in random locations in those two rooms at the back of the house.

After Harvey, those areas at the back of the house were damaged. The restoration company tore out the baseboards and some drywall along the back and they were definitely wet. That's why I think it is the patio.
 

poolnovice1

Bronze Supporter
May 11, 2018
95
Houston
This is Houston, it's possible things have moved around and the house is now lower in relation to the deck from where it was originally constructed. It may be worth calling out a foundation company to put a water level on your slab and see if your house shows to be down on the pool side. Not that it would make the resolution any better, because if that's the case you'd need to break up the deck anyway to have the slab piered.
We haven't seen any signs of foundation damage, like cracks inside the house, windows or doors not shutting, or cracks on the exterior of house. I've walked around the house and there I see no damage to the foundation.
 

poolnovice1

Bronze Supporter
May 11, 2018
95
Houston
It seems odd that the pool is so high, which makes me think that maybe the pool floated.

I would put in at least one dry well so that you can monitor the ground water and pump it out as needed.




Interesting. We have heavy clay soil and a shallow water table. Do you think a dry well will work here?
 

JamesW

TFP Expert
Mar 2, 2011
27,709
Interesting. We have heavy clay soil and a shallow water table. Do you think a dry well will work here?
Check with a local contractor who has experience in ground water control.

It partly depends on what the pool backfill is.

If they used rock, then it is likely to be worthwhile putting a sump tube close to the pool in the rock.

It looks like you could probably put in a tube near the pool wall or just outside the deck on the left.

How shallow is the water table?

Where does the overflow drain go to?

1633976699587.png
 

poolnovice1

Bronze Supporter
May 11, 2018
95
Houston
Check with a local contractor who has experience in ground water control.

It partly depends on what the pool backfill is.

If they used rock, then it is likely to be worthwhile putting a sump tube close to the pool in the rock.

It looks like you could probably put in a tube near the pool wall or just outside the deck on the left.

How shallow is the water table?

Where does the overflow drain go to?

View attachment 377323

The overfill goes to a PVC pipe that runs to the street from the side of the house.
 

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poolnovice1

Bronze Supporter
May 11, 2018
95
Houston
I don't know who else is left to call anymore. I've called plumbers, irrigation guys, drainage experts. We've ruled out leaks in the house and leaks outside the house. I don't think there is a pool leak - did the bucket test. I'm only losing about 1/4" of water per day.

I haven't called my insurance company as they never cover these sort of "gradual" damages.

Here's what the drainage guy has proposed for $8,000:
1) Saw cut and remove concrete 10" wide parallel with foundation for the entire back of house.
2) Dig out along foundation and apply sealant to foundation for this area.
3) Re-install soil to proper finish level allowing for new 5" channel drain installation.
4) Install new channel drain 3" below foundation cemented in place with concrete sloped slightly on both sides of drain.
5) Connect new channel drain to solid 4" PVC SDR-35 drain pipe, with a pipe sloping underground down both sides of house.

I'm thinking about going with this, replacing the floors, and seeing what happens. I don't know what I will do if this doesn't fix the problem. I think we have bought ourselves a money pit.
 

JamesW

TFP Expert
Mar 2, 2011
27,709
In the area at the back of the garage which has poor drainage, I can hit water within a foot of digging. In other areas with acceptable drainage, perhaps two feet.
That's a lot of water.

I suspect that the pool probably floated at some point.

I would think that you would need to create areas of rock that allow for water to drain to a central sump tube so that the water can be pumped out.

Here are some places I found on the Google.




 
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poolnovice1

Bronze Supporter
May 11, 2018
95
Houston
That's a lot of water.

I suspect that the pool probably floated at some point.

I would think that you would need to create areas of rock that allow for water to drain to a central sump tube so that the water can be pumped out.

Here are some places I found on the Google.





Funny enough that last company is the one that has quoted me the $8,000 for the channel drain.
 

JamesW

TFP Expert
Mar 2, 2011
27,709
The house seems low.

Is the house on a slab or crawlspace?

I think that the excessive water in the ground is coming up and soaking the floors.

You probably need to get some serious water management to prevent further damage.

Check with the below company to see what they recommend.

 

JamesW

TFP Expert
Mar 2, 2011
27,709
For any company, verify business license, any necessary professional licenses, bond, insurance, worker's compensation etc.

Check their reviews.

Check with any organizations they claim to be a member of to see if they are in good standing.

1633988829270.png
 

superuser

Well-known member
Nov 16, 2020
195
Spring, TX
We haven't seen any signs of foundation damage, like cracks inside the house, windows or doors not shutting, or cracks on the exterior of house. I've walked around the house and there I see no damage to the foundation.
If you've been there 7 years and seen no movement, that's a pretty good sign.

The house seems low.
Is the house on a slab or crawlspace?

You can see the house is on a slab, and that the deck is even with the top at the left half of the house. Only three ways that happens: 1. Pool moved up with the deck, evenly, with no failure in the hardscape (highly unlikely), 2. The house moved down (in Houston, likely, but generally not evenly). Or 3, it was just built wrong in the first place. If he hasn't seen movement, I'm going for #3.

IMHO your first idea of a recessed channel drain between the slab and the deck is probably your best bet. Grass wouldn't absorb water fast enough with any of these 2 inch an hour rains we get, much less a TS or hurricane. My first goal would be to get some vertical distance so water isn't just flowing into the weep holes and ponding against the bottom plate.
 
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JamesW

TFP Expert
Mar 2, 2011
27,709
Only three ways that happens: 1. Pool moved up with the deck, evenly, with no failure in the hardscape (highly unlikely),
I think that the pool probably floated before the sale of the house and then everything was redone to to make it look as normal as possible.
 

poolnovice1

Bronze Supporter
May 11, 2018
95
Houston
If you've been there 7 years and seen no movement, that's a pretty good sign.



You can see the house is on a slab, and that the deck is even with the top at the left half of the house. Only three ways that happens: 1. Pool moved up with the deck, evenly, with no failure in the hardscape (highly unlikely), 2. The house moved down (in Houston, likely, but generally not evenly). Or 3, it was just built wrong in the first place. If he hasn't seen movement, I'm going for #3.

IMHO your first idea of a recessed channel drain between the slab and the deck is probably your best bet. Grass wouldn't absorb water fast enough with any of these 2 inch an hour rains we get, much less a TS or hurricane. My first goal would be to get some vertical distance so water isn't just flowing into the weep holes and ponding against the bottom plate.
I'll tell you how that happens. The genius who built the deck poured 3-4" of concrete on one side of the house and 0.5" to 1" on the other side.

I went with the channel drain. I emailed the drainage guy to move forward with it. Fingers crossed!
 

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