Fiberglass vs. Gunite Pool Build

[Mcow]

Hi Guys would love some input from this fabulous community that helped me so much on my last pool build. Sorry in advance for the long post and thank you to those who read it. We are building a new house and getting quotes for a new pool (that I told myself I would never build again). Current pool is a gunite pool. I actually considered getting a fiberglass pool at the time but our HOA requires special approvals that can take forever so went with gunite. On the new pool I wanted to compare the two options because there are no limitations. I very naively thought fiberglass would be a less expensive option but turns out it is almost the exact same either way.

Below is a comparison. As you can see the "options" on fiberglass are way more and that is what seems to be driving the cost. I really was only considering fiberglass because I thought it would be less expensive and a quicker construction time. As far as construction time gunite is saying 6 months and fiberglass is much quicker but there is almost a 6 month lead time before starting so will end up being almost a wash. After doing research it seems like fiberglass does require less cost overtime with chemicals and refinishing (according to the people that sell fiberglas at least haha). The other caveat is we have terrible soil. The gunite builder is insisting we add piers which is around an additional $8k. Fiberglass builder said not a concern because fiberglass pools "flex" with soil movement. The gunite builder also included paver decking because of potential soil movement cracking poured concrete decking which is what is priced with fiberglass option. Size wise the gunite is 16'x38' and the fiberglass is 15.5'x40. I quoted this size with the gunite builder to get a close comparison but can save about $4k if we reduce size to 32'x16' which is similar to current pool. Oddly there is not a big cost difference reducing the size of the fiberglass pool but I can do the same size without a spa and save the cost on the heater so $5k less. Big difference is the fiberglass come with a built in spa. We live in Texas and honestly not sure how often we would use the spa. Our pool water turns to spa temps about mid summer so I am thinking this would be used sparingly spring and summer. I am also cheap when it comes to utility cost and we will be on propane so not sure how often we heat. I already know for the gunite option we will not add the heater but wanted it in for cost comparison. I do like the idea of a spa though. It would be cost prohibitive for our budget to add to gunite. The fiberglass also has a splash pad which we added to our current pool but never use so I am indifferent about that. There would be a lot more "swimmable" space in the gunite pool unless we get rid of the spa on the fiberglass. Lastly fiberglass has cantilevered coping vs. precast or flagstone coping included in gunite which aesthetically I like better.

I know both options have pros and cons. Would love to hear feedback especially if you have owned both types.
1-Does fiberglass really cost less for chemicals?
2-Anyone had issues with soil movement on fiberglass?
3- There seems to be a debate on waterline tile for fiberglass. Some say completely not needed others say you need it to prevent discoloration of gelcoat on waterline. Experience on this?
4- Those in warmer clients how often do you use your spa?
5- Since both options are relatively same cost which would you go with and why?

Attaching rendering from gunite PB and drawing of fiberglass option for visual comparison.

Description	Gunite	Notes	Fiberglass	Notes
Base Price	$72,341	$8k of this is piers not included in Fiberglass. Also includes pebble plaster.	$63,680	Fiberglass has built in spa
Heater	$2,900	400k BTU Propane	$5,088	250k BTU Propane
Automation Upgrade	$780		$3,788
SWG	$900	Getting credit removing Ozone/UV included	$2,061
Robot Cleaner	-$95	Small credit because pressure side cleaner included	$0	Did not quote any automated cleaner
Waterline Tile	$0	Mandatory included in base price	$6,495	Upgrade and not mandatory
Total	$76,826		$81,112
Total with options likely to go with	$73,926	No heater	$70,829	No waterline tile or automation

 

[Texas Splash]

Mcow. it sounds like we have the same horrible soil - the black gumbo stuff that shrinks and separates in the summer and then swells and gets soft with heavy rain. We went with our 16x40 FG pool for that very reason. We were concerned about soil movement and heard of some gunite owners who had repair issues. I guess it could go either way, but we're happy with ours. We do not have a spa. My wife still wants a hot tub, so maybe one day we'll just do that. In our area, I don't think I would use the spa that much anyways. As for chemicals, naturally there is no plaster start-up to worry about. After that, you will need to add chlorine and muriatic acid as required like any pool type. But our chemical levels stay fairly constant, and chlorine is the most commonly required items as with any pool. We did not do the waterline tile, some do though. Personal preference. The only potential down side might be future repair/maintenance if a tile decides to come off. As for costs, it looks like those are going through the roof. So much depends on features and such, but back in 2013 ours was about $40K. Sorry. You can see my pool and build from the link in my signature. Perhaps the biggest plus for gunite (IMO) is the ability to customize the shape and depth. However there are so many nice FG models now, it's easy to move past that as well unless you're a big diving board enthusiast. Hope that helps.

 

[Mcow]

Mcow. it sounds like we have the same horrible soil - the black gumbo stuff that shrinks and separates in the summer and then swells and gets soft with heavy rain. We went with our 16x40 FG pool for that very reason. We were concerned about soil movement and heard of some gunite owners who had repair issues. I guess it could go either way, but we're happy with ours. We do not have a spa. My wife still wants a hot tub, so maybe one day we'll just do that. In our area, I don't think I would use the spa that much anyways. As for chemicals, naturally there is no plaster start-up to worry about. After that, you will need to add chlorine and muriatic acid as required like any pool type. But our chemical levels stay fairly constant, and chlorine is the most commonly required items as with any pool. We did not do the waterline tile, some do though. Personal preference. The only potential down side might be future repair/maintenance if a tile decides to come off. As for costs, it looks like those are going through the roof. So much depends on features and such, but back in 2013 ours was about $40K. Sorry. You can see my pool and build from the link in my signature. Perhaps the biggest plus for gunite (IMO) is the ability to customize the shape and depth. However there are so many nice FG models now, it's easy to move past that as well unless you're a big diving board enthusiast. Hope that helps.

Thanks for the info! Yes same exact issue with soil "highly expansive clay soil" . One concern I have here is when we did soil samples and the engineer did the foundation he actually did not recommend piers. He was more concerned with the "potential rise" than the sinking and piers only help with the sinking. Instead he had us do a soil stabilization injection and increased the depth of the beams of the foundation. So I am a little concerned with just adding piers will not prevent issues although I do understand the two situations are not identical and water weighs a lot. Not as concerned about the shape. We actually love everything about the fiberglass model and wanted a rectangle this time. So have you not had issues with discoloration at the waterline? Our pool will be on the north side of the house and no shade so direct sunlight pretty much all the time. Yes pool prices are crazy right now. We were all in at $64k 4 years ago and that included 850 square feet of paver decking (double this), a raised flagstone beam with water fall and 20'x12' cedar pergola. I quoted the gunite option with the same PB and he said my current pool would be closer to $80k today.

 

[Mcow]

@Texas Splash Oh man I am glad I looked at your pool pics because I have an unrelated question regarding your fence since you are also in Texas. I was actually planning on doing the exact same type of fence. We will be in a rural area so no city codes but I have seen there is a Texas property code regarding fences around pools. I know it has to be at least 4' tall and have auto shutting gates. As far as you know does your type of fence meet the code? I saw chain link fences are prohibited and I know this isn't exactly a chain link fence but similar. What size is your grid pattern on the wire? I love the look of this and we do not want to block our view. Plus I can do this type myself fairly inexpensively which is important because if you think pool prices are high you should see cost of building a house right now haha.

 

[Texas Splash]

Our pool is on the west side - 100% full TX sun. Discoloration? ....... yes, we did experience that, but not sure if was related to any one specific thing and it's not a deal-breaker. The fading is something I'm still evaluating to be honest. Above the waterline is easy to buff or polish years later "if" needed. Below the waterline, not all gelcoats seem to react the same to chemicals and the environment, but more than likely even if something fades over time, you will be the only one who notices or cares. Ours was installed before I knew about TFP, so it was placed on, and backfilled with, sand which is more prone to movement. I would recommend gravel for better compaction and stabilization. It's been about 8 years now and we noticed a couple dipping spots around the pool related to our concrete decking (not the pool), so we had a contractor do that polyurethane injection around the decking to level it up and keep it stable. Guaranteed for a few years.

 

[Texas Splash]

As far as you know does your type of fence meet the code? I saw chain link fences are prohibited and I know this isn't exactly a chain link fence but similar. What size is your grid pattern on the wire?

This was definitely an early DIY project, and the soil tried to mess with it as well. Codes? ...... I cannot confirm or deny. We have no small children but do have six dogs, so honestly that's all I was concerned about to ensure one of those boneheads doesn't fall in and panic/drown. So the backside of the pool has no fencing because the dogs are isolated to the front side of the pool. I got that gate material from Lowe's I think. Between the wooden 4x4s I think that's just typical fencing material that from HD or Lowe's. I used the large chicken coup/U-shaped staples and nailed those in to hold it up. It works is all I can say. I too don't want to have something that blocks our view, but I may re-do it later. If I do, I might opt for the cattle fencing material that is more stout.

 

[Mcow]

@Texas Splash Good to know. Yes I was debating using cattle panels instead they are just a lot less easy to work with but the fences I have seen with them are sturdy as heck. The guy across the street from our new house used that. We are actually fencing in a small yard around the house and only to keep our small dog because she is a runner. Our kids are teenagers so not really concerned there. Unless a toddler is wondering rual North East Texas by themselves not really a huge concern.

Oh and yes gravel backfill was added to the fiberglass quote. I actually didn't find TFP until after we started building our first pool and I wish I had because it would have saved me a lot of bad decisions.