Plaster chunks coming off seat in spa - Repair advice needed

[aaronsdad]

Hi All,

My wife and I just bought a house a few weeks ago with a pool and overall everything looks to be in very good shape. A possible exception is one section of seat in the spa that looks to have plaster circles/chunks missing. I don't see this anywhere else in the pool or spa and was hopeful that this community could point me in the right direction for repairing this before it gets worse. Also in case it matters the previous owner use the term gunite so that may affect the repair procedure.

Thankfully, since this is in the spa I could easily drain water to below the seat if needed for repair. Any help is much appreciated. Thank you!!

-Jeff

 

[gwegan]

What does the pool look like? Are they separate? How about some more pictures. Overall pool setup, closeups of more of these dings and those spots on the floor. A picture of the equipment pad. Also some water test results. Pool School - ABCs of Pool Water Chemistry Cl cc calcum hardness ph. Use a drop based test -- no strips. Historically do you know what those numbers have been.

When you tap the plaster does it sound hollow anywhere?

When we get all that we can give you a better idea.

But a few quick thoughts. How old is the pool? Because I think your plaster is old and is beyond its useful life. Depending on how the pool looks you may want to have it all replastered. What are those spots on the floor?

Anyway try and respond to the questions above -- the plaster experts may be along in a day or so and ask more questions and use what you provide to impart more wisdom than I have.

 

[aaronsdad]

What does the pool look like? Are they separate? How about some more pictures. Overall pool setup, closeups of more of these dings and those spots on the floor. A picture of the equipment pad. Also some water test results. Pool School - ABCs of Pool Water Chemistry Cl cc calcum hardness ph. Use a drop based test -- no strips. Historically do you know what those numbers have been.

The pool is a rectangle with the spa centered on one long side of the rectangle. They are joined together and the spa circulates into the pool while the main pump is running (and valves are pointed toward the pool side). I can take pictures tomorrow morning as I'm at work now and it will be dark when I get home. Equipment that I can recall off the top of my head: Inteliflow VS-3050 pump, 58 sq/ft DE filter, single speed spa jet pump, old looking cast bronze heater.

Historically I do not know the numbers. I have ordered the TF-100 test kit and will be using that as soon as it shows up. The current kit I have may be fine, but since it was left by the previous homeowner I have know idea on the age of the reagents. I have taken water samples to a Leslie's two times in the last two weeks. The CYA levels were different each time which made me think the test was, perhaps, subjective in some way. First time was 120 and then two days ago (after which I ordered the TF-100) it was 80. No draining or reverse osmosis on my end. PH was 7.6 which matches my at home test.

According to the employee during my last test at Leslie's my water is perfect and I should put the test results on my refrigerator. However FC was 3ppm which at 80 CYA seems low to me. In any event I can get you more helpful info on good numbers when the TF-100 shows up. As far as I am aware CH was not tested unless that is what they are calling total dissolved solids.

Here are the Leslie's numbers: FC: 3.0ppm, TAC 3.0ppm, CYA 80ppm, TA 100ppm, pH 7.6, Copper 0ppm, Iron 0ppm, Total Dissolved Solids 950, Pho 50ppb

When you tap the plaster does it sound hollow anywhere?

When we get all that we can give you a better idea.

That is a good question and although I'm not really sure exactly what to listen for I can give it a shot.

But a few quick thoughts. How old is the pool? Because I think your plaster is old and is beyond its useful life. Depending on how the pool looks you may want to have it all replastered. What are those spots on the floor?

Anyway try and respond to the questions above -- the plaster experts may be along in a day or so and ask more questions and use what you provide to impart more wisdom than I have.

Pool age is unknown to me. The people I bought it from said it was already in when they bought the house 15 years ago. They said they had it re-plastered 7 years ago.

Spots on the floor are holes for a blower to make the spa crazy. It is kinda fun to watch.

Thank you for your time!

-Jeff

 

[gary300]

Welcome to the TFP forum. You will find many knowledgeable people here and can usually find the answer to any question. You may be able to patch the plaster as holes appear, but in my experience, once the plaster starts to come off of the gunite base you are looking at a re plaster job. Seven years is still fairly new for plaster, unless the chemicals were not kept in balance in which case the plaster can erode quickly.

 

[gwegan]

TF 100 test results would be great. And pictures plenty of pictures.

 

[aaronsdad]

Here is a link to an album of pictures that should allow you to zoom in pretty well. After looking through them feel free to fire away with questions.

Some notes:

1. The only missing "chunks" of plaster that I can see are in the spa.
2. The only other area that I can see where plaster is thin/missing/really worn etc is on the top step (3 pictures in the album of that worn area).
3. The previous owner seemed to really do a good job with everything in the house. He was careful to show me how to operate/test the pool etc and has been a big help with subsequent phone calls. If there are questions that he needs to answer I can reach out, but I'd like to minimize bugging him in general.
4. Yes that is some algae in one (or more) of the pictures. FC was 0.0 when I moved in so I'm working on that too. Separate issue...

Thanks again,

-Jeff

 

[gwegan]

Thanks for the pictures

I've asked the resident plaster expert On Balance to come over and look so give it a couple days to see if he checks in.

 

[onBalance]

This plaster condition is known as "spalling" or "flaking" - where about a one-sixteenth to one-eighth of inch layer has delaminated and broken off in small round areas. It is primarily due to improper troweling when new. But understand that this type of problem usually takes several years to occur after being plastered. It is not caused by chemical imbalance.

It is not absolutely required to fix this problem since the overall thickness of plaster is about a half inch. Unless algae is always forming within the "crater" or for other reasons, it can be left alone. One way to deal with this is to use a power sander and smooth the rough area within the round area and the crevice. Patching with new plaster is not always an effective way to remedy due to how thin it would be. But it can be tried, and I think your spa already has some patches in old spalling areas. Areas of the spa (and perhaps the pool) can continue to develop more spalling over time.

Spalling should not be confused with bond failure where the all of a plaster coat (one-half inch) has delaminated in areas which can be and should be filled and patched with new plaster.

 

[aaronsdad]

This plaster condition is known as "spalling" or "flaking" - where about one-sixteenth to one-eighth of inch has delaminated and broken off. It is primarily due to improper troweling when new. But understand that this type of problem usually takes several years to occur after being plastered. It is not caused by chemical imbalance. It is not absolutely required to fix this problem unless algae is always forming within the "crater" or for other reasons. One way to deal with this is to use a power sander and smooth the rough area within the round area and the crevice. Patching is not always an effective way to remedy due to how think it would be. But it can be used, and I think your spa already has some patches due to spalling. Other areas of the spa (and perhaps the pool) can continue to develop more spalling over time.

Spalling should not be confused with bond failure where the entire plaster coat (one-half inch) has delaminated which can be and should be filled and patched with new plaster.

This is all helpful and very welcome information. The detail on what happens and how to remedy the spalling if desired is really helpful.

I appreciate everyone's input and time looking into this issue for me. Certainly a good forum with good people!

-Jeff