Sinking Deck and Overflow Drain

[paultz]

Hello,

I'm fairly new to this site and have spent the past few months browsing old threads and learning about water chemistry. The TF-100 test kit that I started using this past August and the professional advice on the forum have saved me lots of troubles in maintaining my pool. This site is really a gem!

I do have two questions and would like some valuable answers. First, two pieces of the concrete deck have sinked about 1.5 inches and I'm quite concerned (see attached pictures). What is the best DIY way to raise them up to prevent further possible damage to the pool wall?
Second, I do see an above-ground overflow drain (see attached picture) by the fence but I could not find the drain by the pool wall or in the skimmers. So was the drain buried under the deck? If so, how does it work?

Thank you so much!

-Paultz

 

[YippeeSkippy]

First off, welcome to posting at TFP~ I hope you'll find all your pool questions answered here.

For the sinking deck, I'd suggest getting a quote on soil injection service. They can easily lift that back into place using some mystery-to-me expanding filler. Skippy and I have an area that needs doing also so we've researched this a bit. They drill holes in the decking and inject this filler substance all the while watching for it to be come level again.

foundation lifting foam - YouTube

As to the drain, could that possibly be your backwash drain?

Maddie

 

[Jimrahbe]

Paul,

Show us a picture of the overflow...

Thanks,

Jim R.

 

[paultz]

Thanks a lot, Maddie. I verified that the drain outlet by the fence is not for the backwash. I also did come across the soil injection idea when I searched on Google. It seems an excellent solution. My concern, however, is that the drilling might break the deck slabs since the two sinking pieces were small.

As DIY options, I thought of either using a lever to raise the deck pieces up and then fill some expandable form under the deck using a dispensing gun, or making some cedar wedges then hammer them under the deck to raise the sinking slab up. What would you comment on these options? Has anyone tried these ideas?

First off, welcome to posting at TFP~ I hope you'll find all your pool questions answered here.

For the sinking deck, I'd suggest getting a quote on soil injection service. They can easily lift that back into place using some mystery-to-me expanding filler. Skippy and I have an area that needs doing also so we've researched this a bit. They drill holes in the decking and inject this filler substance all the while watching for it to be come level again.

foundation lifting foam - YouTube

As to the drain, could that possibly be your backwash drain?

Maddie

 

[paultz]

Hi Jim,

Please see the picture, on which I marked the possible drain line direction according to the landscaper's sketch a few years ago. I examined carefully but didn't find any drain by the brim of the pool liner. So I couldn't understand why the pool builder laid such a drain line underground. Any comments?
View attachment 89854

Paul,

Show us a picture of the overflow...

Thanks,

Jim R.

 

[Jimrahbe]

Hi Jim,

Please see the picture, on which I marked the possible drain line direction according to the landscaper's sketch a few years ago. I examined carefully but didn't find any drain by the brim of the pool liner. So I couldn't understand why the pool builder laid such a drain line underground. Any comments?
View attachment 89854

Paul,

Most pools, that have an overflow, either have an overflow pipe with a "grate" at the waterline, or there is a hole in the back of the skimmer.

A lot of pools have no overflow line at all.. I have two rent houses with older pools and neither one has any type of overflow.

Unless you have an obvious exit point or a pipe in your pool wall that seems to have no function, I suspect that you do not have an overflow system.

I have no idea what the pipe in your drawing is for... How big a pipe is it? If 3 or 4 inches, it would most likely be a French drain to remove ground water.. It 2" or so, it could be way to use a pump to remove ground water from under your liner... But, I am just guessing...

Thanks,

Jim R.

 

[erhanuyar]

First off, welcome to posting at TFP~ I hope you'll find all your pool questions answered here.

For the sinking deck, I'd suggest getting a quote on soil injection service. They can easily lift that back into place using some mystery-to-me expanding filler. Skippy and I have an area that needs doing also so we've researched this a bit. They drill holes in the decking and inject this filler substance all the while watching for it to be come level again.

foundation lifting foam - YouTube

As to the drain, could that possibly be your backwash drain?

Maddie

Its called mud jacking and i think its the best long term solution though it is expensive. I do need for my pool deck as well

 

[paultz]

Paul,

Most pools, that have an overflow, either have an overflow pipe with a "grate" at the waterline, or there is a hole in the back of the skimmer.

A lot of pools have no overflow line at all.. I have two rent houses with older pools and neither one has any type of overflow.

Unless you have an obvious exit point or a pipe in your pool wall that seems to have no function, I suspect that you do not have an overflow system.

I have no idea what the pipe in your drawing is for... How big a pipe is it? If 3 or 4 inches, it would most likely be a French drain to remove ground water.. It 2" or so, it could be way to use a pump to remove ground water from under your liner... But, I am just guessing...

Thanks,

Jim R.

Hi Jim,

The diameter of the pipe is about 4 inches. So I also would guess that is for a french drain in my backyard around low spot area by pool deck.

Thanks a lot,

Paultz

- - - Updated - - -

Its called mud jacking and i think its the best long term solution though it is expensive. I do need for my pool deck as well

Thanks for the information and I'll explore this option as well.

 

[PoolguyinCT]

mud jacking certainly has its place, but I’d be very cautious, if that’s not a pured pool wall A frames & deck flights will get moved when the deck lifts.

for the diy route a hammer out & repour for such a small area would be my move.

Either way a deep deep perimeter cut along the work area is needed to segment deck & any footer poured for the coping.

 

[paultz]

mud jacking certainly has its place, but I’d be very cautious, if that’s not a pured pool wall A frames & deck flights will get moved when the deck lifts.

for the diy route a hammer out & repour for such a small area would be my move.

Either way a deep deep perimeter cut along the work area is needed to segment deck & any footer poured for the coping.

Thanks for your advice, PoolguyinCT! Will keep your words in mind when working on this.