poolnerd

The strength and durability of your pool’s structure is one of the most important things to consider when you’re building your pool. Believe me, you don’t want a pool with a structural crack– that kind of thing can take a tall pile of money to fix. Sure, you need to consider things like the steel schedule, make sure the gunite/shotcrete is mixed and applied properly. Yeah, but all that stuff is kind of technical, and, well… boring. Not many people are interested in the gory details.

But what if I told you that there was a way to make your pool much, much stronger? And that it was easy to do, and it wouldn’t cost any additional money.

Interested?

Well, here’s one of the most ignored aspects of pool construction. It’s called “curing.” Simply put, it involves keeping your pool shell continuously damp for a period of time specified by your structural engineer, usually anywhere from five to fourteen days. If your pool is not properly cured, it will never achieve the strength it could — and should — have.

Continuously Damp

The key phrase in the preceding paragraph is “continuously damp.” Many pool builders advise their clients to wet down the pool two or three times a day with a hose. That is usually not sufficient. Hey, most pools are built where it’s hot. A lot of heat means a lot of evaporation. A twice-a-day spritzing is just not enough.

I would recommend you get enough soaker hose to encircle your pool and/or spa. Lay it out on the bond beam (the top portion of the pool wall, usually about a foot wide). Let it weep all day long; just turn it on when you leave for work in the morning, turn it off when you get back home in the evening. You can even add a battery-operated timer on your hose bib so that the soakers will run for like fifteen minutes every couple of hours. This will ensure that the pool surface gets enough moisture, that it cures properly. Water will slowly accumulate in the bottom of the pool, even clear up into the shallow end. That’s OK. After a day or so, you could fill the pool completely and it wouldn’t hurt anything. It will cure just as well underwater, but it’s easier to drain out for the next few phases of work if it’s not completely filled.

Why Curing Is Important

One misconception many people have about concrete (or shotcrete/gunite) is that it gains strength as it dries. Actually, though, if the shotcrete is allowed to completely dry out, it does harden, but it also stops gaining strength at that point. Applying more moisture after that won’t really help.

On the other hand, if the concrete is kept continuously damp for the first couple of weeks, it will continue gaining strength the entire time. The water continues the process of “hydration,” the series of chemical reactions in the cement that leads to a stronger end product. The first set of these reactions are usually done about 36 hours after initial hydration (adding water to the cement). But other phases of the reactions continue for days after that. The concrete slowly gains strength the entire time. Interestingly, the reactions actually continue for perhaps hundreds of years, the concrete slowly gaining strength the entire time.

Concrete– as well as gunite– is considered fully cured after 28 days. If you need to add an additional “load” to the pool, like compact adjacent soil or build a nearby structure, it’s a good idea to wait for the concrete to become fully cured, just to be safe.

Now you’re in the know on one of the cheap and easy secrets of pool construction. If your pool shell is cured properly, it will be much, much stronger than the typical mass-market, cheapie pool. So, get some soakers, and patiently let your pool cure the right way.

This entry was posted on Wednesday, September 13th, 2006 at 7:44 am and is filed under Uncategorized, Constuction, For Homeowners. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.