Can this be stopped?

madgunner

Active member
Oct 13, 2014
27
Austin/TX
#1
Will efflorescence coming through the gunite stop when the pool has plaster and water added?

Can anything be applied to the gunite to stop the efflorescence from leaching through, where this sealer won't negatively affect adding plaster? Something like RadonSeal or DryTreat 40SK?
 

madgunner

Active member
Oct 13, 2014
27
Austin/TX
#2
Photos for the efflorescence / seepage attached.

photo-a.jpg
photo-b.jpg

One photo shows the white build-up leaching from the bottom step and from around one of the pipes. The other photo shows the build-up along the wall in spots near the bench, and lots of still-wet leaking around from around the light fixture.

Every time it rains the areas shown in white tend to grow. After a rain, looking at the concrete, it's obvious where the ground water is coming through near the steps, under the bench, and by the lights.
 

onBalance

TFP Expert
LifeTime Supporter
Jul 25, 2011
856
Utah
#3
Once the pool is plastered, the efflorescence will stop.
The gunite shell is very porous, and what is happening after raining is normal.
Nothing to worry about.
 

madgunner

Active member
Oct 13, 2014
27
Austin/TX
#4
After the hole for pool was first excavated, it rained hard and the hole with rebar framing filled with muddy water - about five feet deep - and didn't lower naturally for more than a week. The hole didn't drain until manually pumped out. The gunite was then installed that same day the water was pumped out. The gunite shell has always had some water at the bottom, a couple inches standing water never dries all the way. I suspect ground water infiltrates continually, and can be watched coming through multiple points right after a rain, especially by the steps and bench where there are no openings.

I'm new to pools... In hindsight, I would've asked for a gravel surround and french drain, and an external waterproof membrane and/or additive in the concrete to resist the ground water. This is a new house near the top of a slope, but not at the top, thus ground water is coming downhill along the modest slope and pressing against the uphill-sides of the pool.

My PB didn't mention waterproofing before construction begun, and hasn't commented on the water or efflorescence other than stating everything is normal, no need to worry. PB, lawyers, and doctors... You need to be your own self-advocate.

I don't want to worry... The Internet has some articles that show how to waterproof a pool using construction techniques, and how this is recommended or required in some areas. My pool is in the free state of Texas and there are no permits or building requirements in my area. If gunite sprayed into a muddy hole and then covered in plaster is _Good to Go_ for a pool and this is truly par for the course, great. But, the ground water infiltration makes me think of rebar corrosion, plaster delamination, and other nightmares. My goal is to enjoy this pool for many, many years...

Before the plaster is added, should anything be done about the ground water infiltration?

EnduroSeal and RadonSeal have concrete sealers that claim to harden and waterproof concrete, penetrating 4 to 6 inches. Can these be used on the gunite? What effect would this have when the plaster is added?

I've got QuartzScape Barbados Blue selected for the plaster/quartz to finish the pool, probably after the holidays.

Endur-o-Seal HyraLoc manufacturer response (from the office manager):
"Yes, this is perfectly ok to apply before the plaster. It’s penetrating so it will penetrate into the concrete to help stop the efflorescence. There will be no problem with adhesion."

Anybody at TFP used a sealer inside the pool on the gunite before the plaster was applied?
 

JayBauman

LifeTime Supporter
Sep 5, 2014
617
Katy, TX
#5
Listen to OnBalance. You'll be fine. Your plaster will keep the water on the inside and any sodium/potassium hydroxides/sulfates (i.e. efflorescence) on the outside of your pool.
 

tim5055

Mod Squad
TFP Expert
LifeTime Supporter
May 11, 2014
10,087
Franklin, NC
#6
As others have said I don;t think you will have problems with efforvence coming through the plaster. But, I will caution you to watch th 4etile line. Mi lot is similar to yours - "ground water is coming downhill along the modest slope and pressing against the uphill-sides of the pool"

The previous owner of my house/pool did not stay on top of it and "efflorescence" did come through the grout between the tiles in several areas. It took a lot of work, but i have beat it back to a reasonable level.

Here is my previous thread about it
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#7
It is completely normal for gunite to leak and completely normal for plaster to be applied without a sealer. If you have ground water up near the height of the tile line, there are things that can be done that are worth looking into, but nothing you have said seems to suggest that is a possibility.
 

BigSwede52

In The Industry
Jul 12, 2015
6
Austin
#8
Madgunner - Being in Austin Texas myself, this condition is not unusual. From your description, it sounds like you may be on a hillside, especially if you are west of IH35, and the water tends to leak in from the one side. The limestone that is prevalent around here has lots of cracks that rainwater drains through for several days to several weeks after a rainfall and this is what is running against the outside of your pool. If this is the case, it is lower hydrostatic pressure than a high standing water table, and is only intermittent not continuous. Pre-plaster pipe penetrations through the pool shell are a weak point in the configuration - the gunite shrinks away from the pipe as it cures - and it in not unusual for some water to seep through at the pipe penetrations, dissolving some salts with the passage (the white build up you are seeing). There are pipe seals that can be installed, but they need to be in place before the gunite is applied. Once plastered and filled, this water migration will stop as there will be a net outward hydrostatic pressure once the pool is filled. However, it would be a good idea to pressure wash the salt accumulations off before plaster application so that you have a good gunite/plaster bond. From your pictures, it does not look like the exterior water table is getting high enough to cause seepage at the water line tile/plaster joint.