Types of Toilets, Features, Installation Advice

Toilets: types, designs, alternatives, properties, installation advice
- Operating Properties Gravity-Flush Toilets & Operating Characteristics of Power-Assisted Toilets & Operating Characteristics of Vacuum-Assisted Toilets
- One-Piece vs. Two-Piece Toilets
- How to cure or prevent sweating (condensation) problems on toilets
BATH & KITCHEN DESIGN GUIDE - separate article
TOILETS, INSPECT, INSTALL, REPAIR - topic home page
TOILET ALTERNATIVES - separte article describes alternative, waterless toilets
TOILET INSTALLATION PROCEDURE - separate article
TOILET REPAIR GUIDE - separate article
Questions & answers aboutthe different types of toilets, toilet features, flush methods, designs & alternatives
References

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Guide to the different types of toilets & toilet designs: this article discusses the types of toilets available, features of gravity flush toilets, power-assisted toilets, vacuum-assisted flush toilets, and the properties of one piece vs two-piece toilets. We also discuss how to stop or prevent sweating (actually condensation) on toilets.

Design Choices & Alternatives for Toilets

As noted in Chapter 6 of Best Practices Guide to Residential Construction:

When water-saving toilets were first introduced in the 1980s, they reduced water usage from 5 to 6 gallons per flush (gpf) to 3.5 with little effect on performance.

However, when Congress mandated in 1992 that manufacturers had two years to reduce water usage to 1.6 gpf, the engineering challenges were much greater.

Most early toilet models were essentially 3.5 gallon designs hastily modified with smaller tanks and narrower trapways intended to increase the flow rate. Most did not work well and required two and sometimes three flushes, negating much of the benefit to water conservation.

Better toilet design and new toilet technologies have led to greatly improved performance in some models. In addition to traditional gravity designs, two types of pressurized designs have been introduced: pressure-assisted and vacuum-assisted.

Both types benefit from the additional flushing power. However, with the pressure-assisted, the increased flush comes with increased noise and complexity (Table 6-11).

This article series discusses current best design practices for kitchens and bathrooms, including layout, clearances, work space, and accessible kitchen and bathroom layout, clearances, turning space, grab bars, controls, etc. We include advice on choosing and installing kitchen countertops, cabinets, and kitchen or bathroom flooring, sinks, and other plumbing fixtures and fixture controls such as faucets. A list of kitchen and bath product manufactures and sources is included. This article includes excerpts or adaptations from Best Practices Guide to Residential Construction, by Steven Bliss, courtesy of Wiley & Sons.

At our toilet home page, TOILET TYPES we discuss the full range of types of toilets available. Also see TOILET ALTERNATIVES where we list alternative toilet designs to basic water-operated flush toilets. Repairing problem toilets are discussed at TOILET REPAIR GUIDE and at TOILET OVERFLOW EMERGENCY. If you are interested in choosing an environmentally friendly toilet tissue, see TOILET TISSUE CHOICES.

[Click any image or table to see an enlarged version with additional detail, commentary & source citation.]

Because there is no standardized testing, figuring out which models perform well is difficult. Test results on individual models performed by the National Association of Home Builders, Consumer Reports, and other groups are a useful guide, but results are not consistent due to differing test methods. While all toilets sold in the United States must meet the American Society of Mechanical Engineers (ASME) performance standard A112.119.2M, this only guarantees basic functionality.

Operating Properties Gravity-Flush Toilets

This is the traditional method, which relies on water dropping from the tank to cleanse the bowl and start a siphon action in the trapway. Although the first low-flow gravity toilets had trouble, many of the newer models have been re engineered with higher tanks and larger trapways to improve the flush.

Some store three or more gallons in the tank to create greater pressure, but only let 1.6 gallons drain in each flush. One side benefit to this approach is less sweating in hot weather, since only a portion of the water in the tank is replaced with new cold water.

Gravity-flush models are generally easy to maintain, although they are a little more finicky than older 3.5 gallon models. For example, the water level must be accurately set for them to work as designed and worn out flapper valves must be replaced with the proper model rather than a generic one.

Among the gravity flush models that consistently rated well in independent tests are any of the Toto models that use its G-Max flushing system and the Kohler Wellworth and Santa Rosa.

Operating Characteristics of Power-Assisted Toilets

Widely used in commercial settings, these toilets have a sealed chamber in the tank that fills after each flush, using the home’s water pressure to compress the air trapped inside.With each flush, the compressed air forces the water down into the bowl with a loud whoosh, which is the primary complaint about these models. As long as household water pressure is at least 25 psi, these are very effective at clearing the bowl.

Because of the tank within a tank, there is no sweating on the outside of the porcelain, but condensation and mildew can form on the surface of the power-assist unit. While these toilets are not for everyone, they are particularly useful in retrofits where drainage is a problem, for example, where venting is inadequate or where the toilet sits at the end of a long drainage run with no fixtures upstream to wash the line.

When these toilets malfunction, the complete pressure-assisted unit is replaced. Power-assisted toilets cost about $100 to $150 more than comparable gravity models.

Examples of top-rate power-assisted toilet models include the Crane Economiser, American Standard Cadet PA, and Gerber Ultra Flush.

Operating Characteristics of Vacuum-Assisted Toilets

A relatively new design, these also have a sealed chamber. With each flush, a partial vacuum is created in the chamber, which connects to the trapway with tubing. The vacuum boosts the suction during the next flush, achieving a powerful flush but without the noise of a power-assisted unit.

Vacuum-assisted toilets use the same flush and fill valves as gravity flush toilets, making them easy to maintain. Only a few models are currently on the market, but they have performed very well in tests and are moderately priced at $50 to $100 more than comparable gravity models.

Among the top-rated models are the Briggs Vacuity 4200 and the Crane VIP Flush 3999.

One-Piece vs. Two-Piece Toilets

Our toilet design photos (below) compare a one-piece toilet design with a traditional two-piece (separate toilet tank and bowl) design. The toilets shown were on display at Menards Lumber Supply in Duluth, MN. - DF

Toilet, one piece design (C) Daniel Friedman

Toilet, two piece design (C) Daniel Friedman

One-piece units tend to have low sleek lines and cost substantially more than standard two-piece models where the tank is bolted to the bowl during installation (Figure 6-55 below).

Figure 6-55, Another example of a one-piece toilet unit.

One-piece toilet models are generally easier to clean, since there are fewer crevices between the bowl and tank to collect dirt.

With gravity flush toilets, it is harder for designers to achieve a sufficient head of water without the height of a standard tank, although redesigning other components has overcome this in at least some models.

[Click any image or table to see an enlarged version with additional detail, commentary & source citation.]

Sweating (Condensation) Problems on Toilets

Details about condensation on indoor plumbing pipes or fixtures are found at SWEATING (CONDENSATION) on PIPES, TANKS.

In humid areas with cold incoming water, sweating on the outside of the porcelain tank can be a significant problem, in some cases rotting the flooring around the toilets. Some of the new flushing strategies alleviate the problem somewhat:

In gravity toilets that store 3 or more gallons of water in the tank, the incoming 1.6 gallons of cold water is tempered by the retained water in the tank.
In pressure-assisted toilets, the incoming water resides in a small tank within the larger porcelain tank, so the porcelain tank is not chilled. However, condensation can form around the inner tank, leading to mold growth.

One approach to avoiding "sweating" or condensation problems with older toilets is to add special foam insulation inserts inside the tank. These may not work with low-flow designs, however. Also this does not prevent dripping from the bowl or water supply line. Where the problem persists, consider added an anti sweat valve (Beacon Valves) that tempers the incoming cold water with a little bit of hot water to bring it up to room temperature.

Kitchen and Bath Product Manufacturers, Sources, Associations

Ceramic Tile-Setting Material Manufacturer List

Bonsal American www.bonsal.com Setting compounds, grouts, preformed shower pans, curbs, and niches. Also, distributor of backerboards, isolation membranes, and other tile-setting products

Color Caulk, div. of Roanoke Companies Group www.colorcaulk.com Color-matched caulking

Custom Building Products www.custombuildingproducts.com Elastomeric and liquid-applied membranes, self-leveling underlayments, setting compounds, and grouts

Laticrete International www.laticrete.com Trowel-on membranes, self-leveling underlayments, setting compounds, grouts, and sealants

Noble Company www.noblecompany.com CPE sheet membranes, trowel-on membranes, clamping ring drains, and preformed slopes, niches, and curbs

Mapei www.mapei.com Trowel-on and sheet membranes, self-leveling underlayments, setting compounds, grouts, and color-matched sanded caulks

Ceramic Tile Backerboard Producers

Custom Building Products www.custombuildingproducts.com Wonderboard cement backerboard, Easyboard cement and polystyrene lightweight backerboard, and Rhinoboard fiber-cement backerboard

Georgia-Pacific Gypsum www.gp.com/build Denshield gypboard backer with glass-matt facing

James Hardie Building Products www.jameshardie.com Fiber-cement backerboard

National Gypsum www.nationalgypsum.com Permabase lightweight cement and polystyrene backerboard

Schluter Systems www.schluter.com Kerdi tile membrane goes directly over drywall or other substrates

T. Clear Corp./Fin Pan Inc. www.finpan.com Util-A-Crete lightweight concrete backerboard

U.S. Gypsum www.usg.com Durock cement backerboard

W. R. Bonsal www.bonsal.com Extruded polystyrene backerboard with fiberglassreinforced cement facing

Cabinet Hardware Manufacturers List

Accuride International www.accuride.com Ball-bearing drawer slides

Amerock Corp. www.amerock.com Comprehensive catalog of cabinet hinges, pulls, slides, and accessories

Grass America www.grassusa.com Cup hinges, slides, shelf supports, and storage accessories

Hafele America www.hafeleamericas.com Cup hinges, ball-bearing slides, pulls, and KD connectors

Mepla Inc. www.mepla-alfit.com Cup hinges, ball-bearing slides, drawer systems, shelf supports, and KD connectors

Hettich America www.hettichamerica.com Cup hinges, ball-bearing drawer slides, shelf supports, and KD connectors

Plastic Laminate Countertop Manufacturers List

Abet Inc. www.abetlaminati.com

Arborite www.arborite.com

Formica Corp. www.formica.com

Nevamar Decorative Surfaces www.nevamar.com

Pionite Decorative Surfaces www.pionite.com

Wilsonart International www.wilsonart.com

Solid Surface Countertop Manufacturers

Avonite Surfaces www.avonite.com

Centura Solid Surfacing www.centurasolidsurface.com

Dupont www.corian.com

Formica Corp. www.formica.com Formica solid surfacing, formerly Surell and Fountainhead

Halstead International www.e-topstone.com Topstone solid surface distributor

Lippert Corp. www.lippertcorp.com

Sansung Staron www.getstaron.com Swanstone www.theswancorp.com

TFI www.tficorp.com

Transolid Inc. www.transolid.com

Wilsonart International www.wilsonart.com

Engineered Stone Countertop Manufacturers

Cambria www.cambriausa.com Cosantino USA www.silestoneusa.com

Dupont www.zodiaq.com

Halstead International www.halsteadintl.com Granyte distributor

Technistone USA www.technistoneusa.com

U.S. Quartz Products www.caesarstoneus.com

Jetted and Soaking Tubs Manufacturers

American Standard www.americanstandard-us.com

Aqua Glass Corp. www.aquaglass.com

Aquatic Industries www.aquaticwhirlpools.com

Bains Oceana Baths www.bainsoceaniabaths.com

Eljer Plumbingware www.eljer.com

Hydro Systems www.hydrosystem.com

Jacuzzi Whirlpool Baths www.jacuzzi.com

Kohler Co. www.kohler.com

Lasco Bathware www.lascobathware.com

Maax www.maax.com

MTI Whirlpools www.mtiwhirlpools.com

Bath Fan Manufacturers

American Aldes www.americanaldes.com Remote location single- and multi-port exhaust ventilators

Broan-Nutone LLC www.broan.com Low-sone Broan bath fans, also single- and multiport remote location exhaust ventilators; Nutone ceiling-mount bath fans

Fan Tech www.fantech.com Remote location inline-duct fans

Kanalflakt www.kanalflakt.com Remote location inline-duct fans

Marley Engineered Products www.marleymeh.com Ceiling-mount bath fans and general kitchen and room exhaust fans

Panasonic www.panasonic.ca/English/ventilationfans Low-sone, Energy-Star-compliant ceiling-mount, inline, and wall bath fans

Kitchen Exhaust Fan Companies

Amana www.amana.com Pop-up and traditional range hoods

Bosch www.boschappliances.com Chimney style, downdraft, and traditional range hoods, stainless steel and colors

Kitchenaid www.kitchenaid.com Retractable downdraft, slide out, island, and traditional range hoods

Broan-Nutone LLC www.nutone.com Nutone downdraft, island, and traditional range hoods

Dacor www.dacorappl.com Commercial-style, stainless-steel pop-up and overhead range hoods; hood liners for custom canopies

Gaggenau www.gaggenau.com/us Chimney-style, pop-up, slide-out, and island range hoods in stainless-steel, aluminum, and glass

Jenn Aire/Maytag Corp www.jennaire.com Pop-up, under-cabinet, wall, soffit, island, and fans and hood liners for custom canopies

Thermador www.thermador.com Updraft, downdraft, and island-range hoods

Wolf Appliance Co. www.wolfappliance.com Pop-up, chimney-style, wall, and island-range hoods in stainless steel

Kitchen & Bath Industry Associations

Association of Home Appliance Manufacturers(AHAM) www.aham.org

National Kitchen and Bath Association (NKBA) www.nkba.org

Ceramic Tile Institute of America www.ctioa.org

Home Ventilation Institute (HVI) www.hvi.org

Marble Institute of America www.marble-institute.com Porcelain Enamel Institute (PEI) www.porcelainenamel.com

Tile Council of America (TCA) www.tileusa.com

-- Adapted with permission from Best Practices Guide to Residential Construction.

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Best Practices Guide to Residential Construction, by Steven Bliss. John Wiley & Sons, 2006. ISBN-10: 0471648361, ISBN-13: 978-0471648369, Hardcover: 320 pages, available from Amazon.com and also Wiley.com. See our book review of this publication.

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The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume. Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.

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