Construction Best Practices

Contracting Best Practices

Pool construction costs in the US typically range from $35,000 to $65,000. Many construction projects are very successful in terms of quality, cost and schedule while others fraught with problems. All construction projects can be impacted positively from best practices that have been developed and improved over the past 50 years.

One aspect of the best practices is the contracting process itself. Often prospective pool owners face as many challenges in this contracting process as they do in learning to care for their pool until they discover TFP methodology.

Contracting best practices are just as easy for the average pool owner as TFP pool care methodology. This post will document basic best practices in construction contracting as they apply to pool construction and pool renovation.

Develop Scope of Work

The first step in any project is to determine the appropriate scope of work. For pools this can be a lot of fun and a little frustrating. Here’s a good way to make it more fun:

• Start with a realistic amount you can afford
• Decide what the purpose is. Is this for the kids, adults, both? Lap-pool for exercise? Year-round, summer only? Budget driven – how much? This should be something you decide early since it will be important in making final decisions on scope
• Decide on your size and layout. There is software that can be useful just Google “pool design software”. Another good thing to do is to look at other pools in your neighborhood. What are the features you like and dislike? Start a post on TFP this site under pool constructions. You’ll get expert advice from people that are selling you nothing, but they get a kick out of helping you set the design specs for the best pool for you. A very rough estimate can be obtained using information at Home Advisor and other sites. You can also estimate at $100/sq ft. The exact price will only be known with a truly competitive bid from highly qualified contractors with a very well-defined scope of work
• You’ll be tempted to want to start talking to a pool builder, but you should resist until you’ve read this entire process and progressed to step 3. You’ll be in a much better position to engage with a pool builder after you know more about what you want and the contracting process itself. Then you’ll be taking them through a best practice bidding process. You should drive the process but unfortunately many are driving by the pool builder before the competition even starts.
• Inadequate scope definition is a prime cause of construction project failures. Make sure the following are decided BEFORE your bid documents are issued:
• Size, shape, depth and depth gradient
• Integrated Spa?
• Decking type (concrete, pavers, other)
• Equipment
• 2-speed or VS pump
• Filter type (sand, DE, cartridge0
• SWG?
• Controls (timer, automation, wifi?)
• Lighting
• Water Features
• Diving board or platform?
• Special Configurations like never-ending pool
• Pool Sub-Panel and capacity
• Pool finish type and color
• In pool features such as swim up table, sun table etc
• Rails, steps and ladders
• Site access limitations and obstructions
• Final grading and site completion requirements

Develop Bid Package

It is desirable to completely define the scope as soon as possible there are certain scope aspects that shouldn’t be finalized until after the bids are received. Hard scope are differentiated from soft scope in the bid documents. For example, the owner may decide they want a variable speed main pump. So this would be considered “hard scope” They may also prefer a manufacturer but want to see pricing for other manufacturers. So the bidders will have a pricing sheet that reflects this. One column lists all the required bid. Another will give the bidder an opportunity to provide a solicited alternate pump manufacturer. A starting point for the Scope of Work and Bid price sheet is given in Section 2. The final pricing sheet should reflect the owner’s preferences, soft scope, and hard scope.

Document Scope of Work and Pricing

The final step in scope development is to document it in tabular format. After all the decisions are made about scope, hard scope, preferences and solicited alternates there is one final decision. How do we want the pricing broken out? This is important if late changes are necessary since the more detailed the price break-down the easier it is to negotiate fair pricing for changes.

Successful bidding occurs when the following are accomplished:

• Scope of work is finalized and clearly documented
• Obligations of the contractor are clear and understood by both parties
• Obligations of the owner are clear and understood by both parties
• The best possible contractor is found and wins the bid.

Pool construction is complex and there are always some unpredictable events. When the points above are achieved there is a good foundation for cooperation of both parties and the outcome is always the best possible.

Cantilevers

Cantilevers generally should only extend 1/3 of the overall length. If you want an 18" overhang then you'd need 36" completely supported behind it. The wider the ledge, the thicker it will need to be.

Equipment Pad Best Practices

See Equipment Pad Best Practices

Trench to Equipment Pad

18" deep minimum. You can start at the level the pipes come out of the pool, then 90 up to the 18" depth. The width should be wide enough that all the suction and return lines can lay horizontally side by side. If you have a spa or water features, the number of lines can add up quickly. A 36"-48" wide trench is not uncommon. A simple pool can be 12" wide.

Placing 2" of clean sand above and below the plumbing will help to protect the pipes.

Gravel Use Around Pools

See Gravel Around Pools

Soil Backfill and Compaction

When soil is excavated it is fluffed up and aerated. If you just dump it back in the excavation it leaves a massive amount of air space in the soil. Over time the soil will compress and fill the air pockets (settle). This can take many years depending on the soil type and how much moisture is introduced to the area.

The proper way to place soil back in any excavation is to compact it in lifts. This means putting in a maximum of 12" of soil then running a compactor over it which Is rated for that depth of lift and soil type. Then place the next 12" in and rinse and repeat until you get to the top. The compactor compresses the soil to get the air pockets out.

Pools should be placed on virgin soil, never dug soil that was compacted. If areas are overdug they should be filled with the appropriate gravel.

When a Pool Builder dumps dirt for backfill in an area they are planning a concrete deck and expecting the concrete to span over any settling that may occur, the concrete will span settled areas short term but it wont last. It is much cheaper and easier to do it right from the start with the proper compaction and gravel. You don't want to be looking at cracks or birdbaths in a few years

Gunite Spa Design

See Gunite Spas

Rebar

For rebar engineering specifications read Reinforcing Steel and Swimming Pool Construction by Pool Engineering.

Gunite Application

Cold Joints

Cold joints in shotcrete (gunite) are in some ways a myth. Laboratory testing has shown that multiple layer shotcrete has no anisotropic weakness (cold joint) when the layers are applied within 7 days of each other. In the real world a plane of weakness often develops between layers, but it's almost always due to improper surface prep. Dust, dirt, and rebound from shooting adjacent areas will accumulate on the first layer during/after the shoot, and if not thoroughly removed prior to applying the next layer a plane of weakness will develop. If the first layer is troweled smooth it can also impede bonding of the second layer. If too much time passes between layers a cold joint is possible, but in that case the reduction in strength is pretty minimal as long as the surface is properly prepped.

Gunite Over Multiple Days

The pool shell can be poured over multiple days. There wont be a cold joint if they prepare the unfinished edge correctly. This is common on very large pools and commercial projects since you simply cannot shoot enough gunite in one day.

Watering New Gunite and Concrete

See Watering New Gunite and Concrete

Proper Construction Techniques for Cantilevered Deck

Construction Techniques for Cantilevered Decks

Sequence of Tile, Coping, Deck for Plaster Pool

The consensus seems to be to do tile, then coping then deck although it can vary with the shape, materials, and contractor preference.

Simple logic is you always build from the bottom up not the top down. In a pool you want the tile to set perfectly level so the water line looks correct all the way around the pool. If the coping is set unlevel then they need to adjust the tile and the seam in between the tile and coping will not be uniform and basically throw the whole tile install off.

It can be done either way however if you ask the actual installers most of them would prefer the tile first then coping.

Here are some things to consider:

Tile

• Do the tile before coping on gunite pools.

Coping

• The coping will set the elevation for everything else around it.
• A professional should be able to take one tile/piece and figure out the measurements.
• You want everything to drain away from the pool therefore you should start at the pool.
• With natural stone coping you lay it first. Don't let anyone tell you otherwise.
• You cannot make demo saw cuts to round the backside for curves with concrete in the way. It can be done but it is not by choice and way more work.
• Coping thickness and setting bed thickness varies. You let the coping set the elevation and work from there.
• You want 1/8" pitch away from pool in all directions and plan ahead for drainage

Deck

• Why would you want the coping crew to work on top of your nice finished concrete deck if you don't have to?
• They could lay down a protective layer of some kind, but they probably won't.

Coping

See Expansion Joints and Coping

Waterline Tile

See Waterline Tile Installation

Plaster Installation

See Plaster Installation and Maintenance

Well Pit Pipe

• going down to depth of pool is the best way
• make hole twice the size of pipe
• 24-30" hole for 13" pipe
• use woven heavy septic fabric
• hang strips of filter fabric down the sides of the hole
• perforate the pipe with a drill to a foot below the top of fabric
• zip-tie fabric to the pipe
• place pipe in the middle of hole
• add some more stone a few inches up then backfill
• backfill with clean 3/4 stone
• pipe the discharge and electric underground
• put a skimmer lid on it or an end cap depending where it is

Concrete Deck

• While a sand or gravel base is not needed it is helpful over the clay. At the very least you want to make sure the subgrade has been compacted.
• "Typical" rebar spacing for deck/sidewalk is #3 (3/8" rebar) at 18" spacing. You also see a lot of welded wire fabric for residential sidewalks but don't settle for that in the decking. Fibermesh (small fiberglass fibers in the concrete) should just be used as a compliment to the rebar and not as a substitute.
• I doubt they would pour anything less than a 3000psi mix but get the mix design/strength in writing
• control joints (either sawed or tooled) will give the concrete a weakened point to crack. Sawed joints give a more cleaner look
• If you are pouring against coping or existing concrete (foundation, sidewalk, garage, etc) you will also need expansion joints. These are typically black fiber board or redwood. The expansion joints have some compression give and will allow the concrete to expand and contract against to prevent cracking and movement.
• when it is time to install try to have them pour before noon before it gets to hot and they have to add more water to keep the concrete workable (which could result in small hairline shrinkage cracks). If possible, check the time on the concrete ticket to see how long the truck has been on the road, more than an hour is unacceptable and grounds to reject the load. The longer it has been on the road the more water will have been added to it.

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