2011 March | Precision Pool Construction Inc.

Dealing with a High Water Table During In-ground Pool Construction

By JayB on March 31, 2011 / pool contruction / 3 Comments

Ground Water Issues with In-ground Pool Installation Salisbury, MA

Ground water durring an in-ground pool installation in Salisbury, MA -click to enlarge

The first thing a pool builder must learn when building in-ground swimming pools is how to handle a high water table. A pool’s finished height in the yard should not be compromised by a high water table. The builder must gain control of the ground water during construction until the pool is finally filled. An under drain must be installed underneath the pool’s rough construction. This would consist of a 1 ½” pvc line buried in ¾” stone at least 18” below the final desired depth of the pool. A reputable builder will leave the homeowner a way to access an under drain for future use when draining the pool is required.

When we install an in ground swimming pool in an area that has a high water table we must get control of the water at a level 1’ below where we are working. To do this you must determine how much water you are dealing with and how deep into the water table you will be working. To completely control the ground water in a pool dig you must have ¾” stone banked as high as the water table. The object is not to stop the water it is to control where it goes. When the ground water runs into the hole it hits the stone and falls to the bottom of the excavation. At least 18” below the finished surface we install an under drain beneath the pool. This line will run underneath the entire pool to the surface of the yard where a self priming pool pump will be hooked up to the end and pump the water from beneath the pool. We will use between 15-30 yards of ¾’ crushed stone in a pool dig with a high water table. The material you are digging in will determine how much stone you will need. If the soil is tight like clay then you will not need as much stone to dewater the hole. The tighter the soil the less it will clog the stone as the ground water runs through it. If the soil is loose and sandy then much more stone will be needed to control the water. The looser the soil the more fines in the material will clog the stone. Therefore you will need more stone to keep control of the water.

In 21 years of installing pools I have never run across a site where we could not control the water. Now, having said that, not every area we have installed these pools was a great idea. One thing to consider when installing a pool in a high water table is to adjust the bottom of the pool not the height of the pool. You are installing an “in ground pool” not an above ground pool or an ant hill . Either bring the finished depth up out of the water table by making the pool 6’ deep instead of 8’ deep, or adjust the interior slopes with in the pool so they are more gradual and allowing you to bank the stone higher. You will have to abandon a diving board when opting for either of these two options.

Dealing with a high water table in an inground pool installation MA

Notice how the pump is still running under the stone during construction

Sometimes the hassle of being deep into the water table is not worth going for a diving pool. I know, I own one of these pools. While digging my own swimming pool we were digging in all sand and 4’ deep into the water table. If you have ever been to the beach and dug a hole down by the water you will know how hard it is to dig a deep hole in the sand with the water rushing in. In my case I could only get 7’ of depth before the water and cave- ins were unbearable. Not enough water depth for a diving board but plenty of depth for the 360 degree slide we have running into the deep end. It took my three children about as long as it took to climb the ladder on the slide to get over the fact we were not going to have a diving board. Don’t be afraid of the ground water just get control of it. Be practical about how deep you want to go into the ground water. Believe it or not we hit ground water on at least 40% of all the pools we build in our area of New England.

How Much Does It Cost to Replace an In-ground Vinyl Liner?

By JayB on March 29, 2011 / in-ground pool cost / Leave a comment

When you have a vinyl liner in-ground pool the time will come where you will need to replace the pool liner. This is ofter 10, 15, even 20 years down the road but eventually the day will come. Liners can fade and become brittle from the constant sun, chemicals, and plain old weathering. The good news is when replacing you vinyl liner its almost like giving your old pool a fresh face lift, it will feel almost new again!

The cost of replacing a vinyl liner in a swimming pool will depend on a few factors:

• Size and shape of the pool: Of course the bigger the pool the more the liner will cost. If there is a special shape to the pool or steel covered steps and bench seats these will also add to the cost of the liner.

• What condition is the pool in: The better the pool has been taken care of then the cheaper the replacement liner will be. If a pool has constant leaks that have gone unattended over the years then you can expect an up-charge to repair the damage done to the walls and bottom of the pool. Excessive leaks over time will contribute to the erosion of the pool bottom and walls. If the walls become too corroded then you may have to install a foam layer over the walls to protect your new liner from the roughness of the rust.

• What condition is the floor of the pool in: A liner replacement will cover all minor repairs to the floor of the pool. If you have a stone dust or sand bottom in the pool then it will need to be raked and re-troweled before the new liner goes in. If there is a hard bottom (vermiculite, concrete, gunite..) then any divots, dents or cracks with separation need to be filled. If there is extensive damage to the bottom of the pool (wash-outs, large cave-ins) then there may be an extra charge to repair these issues.

• What condition is the coping in: The liner snaps into a track at the top of the pool which is referred to as coping. Coping is a vital element in replacing a vinyl liner in a swimming pool. Aluminum coping will corrode over a period of time and plastic coping has a chance of becoming brittle down the road. You need to inspect the coping to make sure a new vinyl liner will be able to be properly hung at the coping edge. If you do not repair the coping before replacing your vinyl liner it could lead to the liner failing very prematurely. If the liner begins to fall out of the coping then the liner will begin to shrink and re-pulling it back into the coping could prove to be a very difficult task.

In ground pools with all of these items in good order will have a vinyl liner replacement cost of approximately $2,500.00-$5,000.00 depending on the size and complexity of the liner. A pool inspection is a must to give an accurate cost to replace the pool liner in your particular pool. Your pool professional should be looking for these items to price the job correctly.

If you need your looking for vinyl liner replacement in Massachusetts or Seacoast NH please feel free to contact us here.

5 Best Vinyl liner In-ground Pool Options and Upgrades

By JayB on March 23, 2011 / in-ground pool options / 1 Comment

Vinyl liner pools have certainly changed over the years. In the early years, other than size of the rectangle, if you wanted options with your pool the choices consisted of stairs or a diving board. Flash forward to the present and negative edge vinyl liner pools are a possibility. Now every imaginable shape, size, stair, bench, water feature …..etc. is available.

The five most common in-ground pool options in today’s pool market include:

1. In floor cleaning system: A properly installed cleaning system will make owning a pool a much more enjoyable and environmentally friendly experience. In floor cleaning systems will not vacuum out every speck of dirt from the pool bottom but it will make it so you will just have to brush a few areas where dirt will settle. Another huge benefit of cleaning systems is the way they return water to the pool. Cleaning systems are designed to move debris down to the deep end of the pool and allow the main drain to suck the debris into a top side canister. When you are heating the pool the hot water is always being returned to the bottom of the pool. The warm water will travel up all the way through the whole body of water rather than being returned to the top 16” of the pool’s surface in a normal pool return. This will prevent cold spots in the pool and will minimize the heat loss during heating times.

How an in-floor cleaning system works

2. Vinyl covered stairs and swim out seats:…….rather than the typical white plastic step which is included with the vinyl liner pool kits, vinyl covered stairs and bench seats have become very popular. Covering the stairs and bench seats will allow you to cantilever the deck over the edge of the pool and give the pool the desired natural look. Using the same pattern on the stairs and bench seats as the floor of the pool will give you the same effect as a gunite pool with all of the benefits of a vinyl liner pool.

3. Heaters: Gas heaters and heat pumps have certainly become a big option when installing a new pool. I would say approx. 70% of the new pools install a heater. The more common issue is whether to go gas or electric aka. heat pump. The fastest way to break the two types of heaters down is this; if you want to heat your pool up on a Friday night for a pool party on the weekend then you want a gas heater. If you want your pool to be 80 degrees all of the time then a heat pump is a better alternative. You will pay more up front for the heat pump but you will get back your initial investment over time in fuel savings.

4. Lighting: Lights have also come a long way since the inception of underwater pool lighting. LED lighting is the newest rage in pool lighting. LED lights give you the effects of fiber optic lighting but the LED lights actually light the pool up. Fiber optic lights are more of a mood light rather than a swimming light. Led lights now have themes such as; sunset mode, fourth of July, Caribbean, Halloween….etc. They all also have a white setting so if you just want to light the pool for safety then that is also an option.

A pool with a pentair Intellibrite LED pool light

5. Water features: From sheer decent waterfalls to fiber optic deck jets water features are a way to add flair to an ordinary pool. Waterfalls are tough to achieve unless you have a reason for them to be there. What I mean by this is to make a waterfall look natural you have to have some change of elevation within the landscape. If you do not have a change in elevation then a sheer decent waterfall built into a landscape feature (planter, two sided raised bond beam) is a way to get the waterfall effect without it looking like the waterfall is coming from an unnatural pile of rocks.

Sheer Descent Pool SIde Waterfall

If you interested in learning more about the design possibilities of a vinyl liner in-ground pool and are located in either Massachusetts or Seacoast New Hampshire Request a free on-site pool consultation here>>