swimming pools: fiberglass vs gunnite

Discussion in 'After Hours Lounge (Off Topic)' started by Ted Lee, Aug 16, 2005.

  1. Ted Lee

    Ted Lee Lead Actor

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    hi all -

    some may recall that i'm thinking about doing a pool. i thank all those that previously replied ... but now this thread is specifically about why you chose fiberglass or gunnite.

    from what i can tell, fiberglass has the following benefits:

    1. lower maintenance
    2. structurally more stable
    3. smoother surface

    gunnite gives you more flexibility in designing the layout.

    however, from a cost perspective, i'm being told they're close ... close enough that it shouldn't be a consideration.

    so, i was just wondering what you all think, why you went with one over the other, etc.

    thanks!

    ted
     
  2. MarkMel

    MarkMel Screenwriter

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    Fiberglass can stain and it is very hard to fix, gunite can stain but it is easier to fix. To me any problems with gunite can be fixed a lot easier than fiberglass. For example a gunite pool can be resurfaced rather easily where fiberglass it seems to me it would be much harder.

    However, with a fiberglass pool, they just dig a hole and drop in the shell, fill it up and you're done (simplified). Gunite as you know has many more steps for installation.

    We went with gunite and I am very happy with it.
     
  3. Scott Dautel

    Scott Dautel Second Unit

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    I dont believe Fiberglass is priced virtually same as Gunite/Shotcrete. When project is complete, I believe you will find FG to be about 20% cheaper for similar size (water surface area).

    The better FG manufacturers offer a lifetime warantee on the shell ... I was particularly impressed with Viking pools. I don't think you are likely to have a problem with the inside surface of FG, it's quite durable and long lasting. Of course, if a vandal ever tosses a chair/lawnmower/etc into your pool, FG could be a complicated repair compared to plaster over concrete.

    With FG, you will be limited to a generally smaller pool. For our family ... The deep end (9') is our favorite part of the pool. This is generally not an option in a FG pool. Also, FG pools seem to be limited to an overall length of about 32' max., but even smaller is much more typical.

    The BEST benefit of FG is the quick build time ... It can all be done in 2 weeks or less. Our 9 month (Aug-May) construction project for our Shotcrete pool (slightly different mix vs. gunite) was torture. Also, all the trucks tore up our driveway, particularly the concrete trucks (60,000 lb). OF course, with FG, you still have to dig and will likely pour a concrete deck around the pool.

    The biggest problem I had with FG was finding a Viking rep/contractor in my area (mid-Atlantic) ... they were few & far between and they seemed to not want new projects that were > 50 miles from their home base.

    Another concern with FG is the possibility that the pool could "float" (i.e. pop out of the ground), should you have a flood or high water table on your property and ever lower the water level in the pool (winterizing?). This virtually never happens with a heavy (8"-12" thick) concrete pool.

    Overall, We generally felt better about the durability of a concrete pool. People I know in the biz also say the value of concrete pools are easier to recoup when you move compared to FG or vinyl liner (vinyl is virtually zero). Comnbine this with unlimited design possibilities and no extra charge for pool depth ... concrete was right for us.

    I thought you liked the idea of a "beach entry" and other unique features?

    Heres a Pic of our results:

    [​IMG]


    Scott
     
  4. Kirk Gunn

    Kirk Gunn Screenwriter

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    It's been a while, but we had friends build a fiberglass pool and the bottom seemed to scratch easily. Of course we were living in Daytona at the time, so sand was everywhere...

    Good luck - when will the AHL pool party be scheduled ?
     
  5. Ted Lee

    Ted Lee Lead Actor

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    thx everyone ... scott, i can't see a pic.

    and to address some of your points (at least from what the pool guy told me)i'll have to ask about staining ... i don't think that came up. as far as fixing, the dude said to really correctly fix a gunnite pool, they have to redo the entire plaster surface, not just the affected area (as it's a "quick fix").

    thanks again guys ... you gave me some more stuff to ponder. [​IMG]
     
  6. Eric_L

    Eric_L Screenwriter

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    I have heard of cheaper fiberglass pools having 'bubbles' in the glass which blisters and can cause problems.
     
  7. Mary M S

    Mary M S Screenwriter

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    The blister issue is one I would highly recommend researching. We are rehabbing a 25yr old Catalina sailboat, (which came with a blistered bottom). I have tried to determine our best repair to stop/slow the osmosis in the future.

    If these pool shells are laid up like fiberglass boats, this will affect the life span of product. And all Fiberglass pools will eventually blister. If similar to marine construction methods and they use a mold, impregnating resin into/onto mats or cloths woven or chopped I would assume they would have the same propensity of boats to blister. Regarding watercraft, the best consensus as to what creates the problem are two fold, First a critical bonding layer between the outermost hull (smooth gelcoat) which is laid into the mold first and the next layer of the process (usually chopped or woven resin impregnated fiberglass) and the connection between these two layers has proved an Achilles tendon in creating larger microscopic pores which over time give egress allowing the process to begin. The second issue is fiberglass itself and the solvents which to greater and lesser percent are present in all materials used during fiberglass lay-up and production. The process of osmosis starts after fiberglass is in constant contact with water and being permeable allows water to filter into the material, which begins to interact with the solvents. Eventually (in many years) depending on the amount of solvents in the product, stress fractures which occur over time, and the inital quality control during chemical bonding of the of the lay-up, the fiberglass sooner or later, becomes saturated, resin starved and then delaminates, leading to weakening and failure of the structure.

    Owners of boats, fighting the battle of blisters as the process manifests, face hauling the boat out of water, - drying out hulls for months till a water saturation meter records stable moisture levels, expensive barrier coats, grinding of the blisters, repairing the fiberglass layers in contact behind the blister (like a reverse volcano). After repair, then your faced with costs of slowing futher blistering, by adding a new thin layer of the most expensive least permemble and high quality resined mat over the boats entire underwater hull, barrier coats etc. etc. All part of the process of the repair.

    A difficult thing to do in the distant future of a concave fiberglass hole in the ground as it ages! I would arm myself with knowledge on the subject before I made my final choice, especially if your adding a long-term note to your home for construction costs. (if you intend to move in 10 years, prob. no problem for you).

    Here’s a link on the topic. Do not believe your salesperson regarding whether this issue has been fully addressed in the pool industry, Fiberglass boats have been around much longer and there is no consensus on how to reduce the time it takes for osmosis to advance to blisters or even agreement upon which repairs have the longest effective life span after blistering begins. Find out which process they use for manufacture, and which resins etc, some are known to have greater levels of impermeability (therefore longer resistance before breakdown) than others. For example vinylesters are considered more resistant than polyesters, however polyesters being less expensive are often used. Etc.
    http://www.daviscoltd.com/nams/Docum...er_Report.html
     

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