Can You Drain a Pool for Resurfacing After Heavy Rain?

Almost every pool resurfacing starts with an empty pool. That is routine, but it carries one risk that matters a lot in a rainy part of the country: water in the ground can push on an empty pool shell. This guide explains the risk in plain terms, what the sources advise, and what to ask a Macon provider before they drain your pool.

Why an empty pool is different

A full pool is held down by the weight of its water. Take the water out, and the shell can be pushed upward by groundwater around it. Swim University says that without the weight of water, the pool "may be pushed up and out of the ground," and that all inground types are at risk, including concrete, gunite, vinyl and fiberglass. This is sometimes called a pool popping.

The risk goes up when the ground is wet. Swim University calls draining right after heavy rain the worst timing and says the soil can stay saturated several feet down even when the surface looks dry. This Old House advises draining only in dry weather when the water table is low, and avoiding it if rain is expected.

Macon's rain

The National Park Service says Macon has a humid subtropical climate with about 45.7 inches of precipitation a year. That is plenty of rain, so wet stretches are normal here. We did not find a source on how high the water table runs in Bibb County or on how Macon's soils behave, so we make no claims about that. What the pool sources do say is that the time to plan a drain is after a dry spell, and that the provider should know how to check.

How providers reduce the risk

According to the sources we read, these are the common steps. They describe general practice, and your provider decides the plan.

• Check the weather. Choose dry weather and avoid draining when rain is forecast.
• Check the water table. Sources say to drain only when the water table is low. Ask the provider how they judge that for your yard.
• Use the hydrostatic relief plugs or valves. Many inground pools have them in the floor to let groundwater in and equalize pressure. Sources say to open them only once the pool is mostly drained, to keep pumping while water enters, and to put the plug back before refilling.
• Drain partially when possible. One source suggests draining only half the water if the reason for draining allows it. A full drain for floor repairs may call for a professional.
• Direct the water away. Water spilled next to the pool adds pressure to the ground around it. Send it to a sewer cleanout or downhill and well away from the pool, as the sources advise. Ask the provider where the water will go and whether any local rules apply.
• Keep the empty time short. Sources say not to leave an inground pool empty for long. One advises keeping the surface damp if it will sit empty more than a day. Another warns against draining in extreme heat, which can damage empty surfaces.

Relief plugs help, but they are one part of the plan and not a guarantee, which is another reason to leave the drain to the provider.

Do not drain it yourself

For a resurface, draining is part of the contractor's job. The risk of lifting a shell, damaging plumbing or discharging water in the wrong place is high enough that we suggest you let the provider drain and refill the pool, and that you ask them how they do it. It is also worth reading your homeowner's policy to see what it says about pool damage.

Questions to ask a provider

1. Who drains the pool, and when will you decide it is safe?
2. How do you check groundwater and the relief plugs?
3. What happens to the schedule if it rains the week before?
4. Where will the water go, and do any local rules apply?
5. How long will the pool be empty, and what do you do to protect it?
6. Is draining and refilling in the quote? Cost guides list draining and refilling as separate line items, with figures such as about $175 to $225 to drain and about $55 per 5,000 gallons to refill. Quotes vary with the size of the pool and the plan for the water, so the real price for those steps comes from the provider who will do them.
7. Who tests the fill water and handles the balancing when it is full?

Refilling and the water you use

After the finish is on, the pool is filled with water. The Macon Water Authority, the local utility, describes the Ocmulgee River as its source, with water held in a reservoir called Javors Lucas Lake, and says chlorine, chlorine dioxide and fluoride are added during treatment. The report lists a highest chlorine reading of 1.7 ppm. It does not list hardness or pH in the sections we could read, so test the water that goes into your pool rather than assuming a number.

One cost guide says a new finish takes about 28 days to cure fully, with a few days of refill and start-up after the finish goes on. Follow the provider's start-up instructions closely.

Safety note

Draining, relief plugs and acid are not casual tasks. Do not start a drain before talking to a professional. Store pool chemicals cool and dry in their original containers, and never mix one product with another chemical, because some combinations release a toxic gas. Follow the label and ask a professional when in doubt.

Request a quote

Planning a resurface? Send a request through this site and a Macon-area provider can walk you through how they would drain and refill the pool. Asking costs nothing and you do not have to hire anyone.