TYPES OF DECK COATINGS
What kind of deck coating do we have on our deck?
This is a very common question, one that is often difficult to answer, especially when only looking at a picture. Visual inspection and sometimes destructive testing will reveal the type of coating, if not the manufacturer. It is important to know what type of coating one has on their decks, as most coatings that are similar have very similar maintenance requirements. At the worst, knowing what type of coating will suffice for probably 90% or more of your needs.
Differentiating between some coatings isn't easy, however, some things to look for can help you tell what type of coating one has. Slip sheets usually sound hollow when tapped on with a spoon. A flat finish also indicates a slip sheet. Urethanes are usually given away by the presence of sand in the top coat. Metal lath systems and fiberglass systems look alike as the top finishes are usually done the same way, so they are difficult to tell apart by just looking at them. Vinyl decks will look like your kitchen floor, Pebble Bond Systems have a unique look and so does Magnesite.
I have broken down the typical deck coatings found on many homes, HOA's and Apartment Communities into seven distinct types of coatings and down below, also listing the manufacturer's we know make them. Many manufacturer's of these types of systems make several types of coating systems, for example, Mer-Kote Products manufacturer's a slip sheet system and they also make a metal lath system too. Excellent Coatings and Hill Brothers make metal Lath & Acrylic coatings and they also make Fiberglass systems. Click on the blue link to go down the page to what you want to see.
- Slip Sheet Systems Dex-O-Tex & Mer-Kote
- Fiberglass
- Metal Lath & Acrylic Modified Cements
- Vinyl
- Urethane
- Magnesite
- Pebble Bond Systems
New in 2007, reports issued by ICC are taking Wind Ratings into account for deck coatings. This will be a very important issue to watch out for; some deck coatings are rated for buildings in high wind zones-up to 120-150 mph. Some deck coatings have ratings for wind zones that are much lower-80 mph. The other tricky factor that will trip up many is the building height. Many coatings are limited to buildings that are 40' in height or less. Has your installer read and understood the plans? If they specify a product that doesn't meet the ICC codes and city building requirements, there may be a liability issue. This problem applies to all different types of deck coatings,
Don't get blown off your decks with the wrong coating!
Fire ratings for deck coatings available are Class A, Class B and so on as well as a separate "One Hour Rating". Thoroughly check out any coating you may be considering for it's fire rating. You don't want to find our after the fact that you need a fire rated coating over your deck. Click here to go to Professional Roofing magazine; an article on fire ratings will help you understand. You can also click here to go to Underwriters Laboratories for further fire rating information.
It is extremely important to know and understand that One Hour Fire Resistive deck coatings can have very different requirements in order to get a One Hour rating. An example is Polycoat Products Polycoat Walking Deck ICC rated ER-4789 urethane system requires 3/4" Plywood with 2" x 10" joists. Then look at the requirements for Desert Crete from Hill Brothers. Their ICC ESR-1661 report requires 5/8" plywood over 2" x 8" joists.
There are big differences with different coatings, one in terms of costs of framing, certainly, but also calculating loads, footings, and clearances.
A client recently inquired about Fire ratings, looking to substitute one product instead of the specified metal lath system called for on the plans. They couldn't find an installer locally for the specified products in their area.
A review of the project showed the first building was already framed out and 2 more were coming fast. The building framed out had deck joists that were 2" x 8" with 5/8" plywood on top. Then we looked at the mfg's ICC report. Big problem! The proposed alternate product called for a 2" x 10" joist for the One Hour fire rating.
Check plans carefully before allowing just any bid on a One Hour Fire Rated deck coating-you might get burned!
Another good site to look at is Coatings Advisor - Your source for coating products and services. This site contains tons of pages on various coatings, including deck coatings, epoxy, and every other type of coating you can think of.
Here is a basic discussion on the deck coating categories . Links to manufacturer's are below each category listing. You will note that manufacturer's may be listed in multiple instances under different categories, that is not a mistake.
Slip Sheet Systems
www.merkote.com www.dexotex.com
Slip Sheet decking is a coating that is comprised of multiple layers of materials over a paper that "slips" over the plywood deck surface. These systems are chemically bonded only to the flashings around the perimeter of the deck. There are only two manufacturer's of slip sheet systems, Crossfield Products Corp (Dex-O-Tex) and Mer-Kote Products Inc.
The theory here for slip sheet systems is that framing and plywood decks move as a natural course from heat/cold, expansion/contraction. The slip sheet moves with the deck/framing, allowing it to flex without cracking.
Proper preparation is vital on these systems, and cleaning the flashings of bond breaking oils is absolutely essential, as is venting the decks to allow moisture to escape out.
Careful use and strictly following the manufacturer's maintenance instructions will ensure maximum life from these coatings. Of the two, Mer-Kote has the least resistance to damaging UV; the Weatherdek© system relies heavily on a lot of regular maintenance.
For HOA's, slip sheets are probably not the best option available; high maintenance combined with low UV and damage resistance suggest that you look for other options.
Mer-Kote's Weather Deck coating system apparently is not a One Hour Fire Rated system; on their web-site is a page that has a "One Hour Addendum" to achieve a One Hour Fire Rating (critical to have, especially on decks over living spaces or garages.) See Mer-Kote's page by clicking here to go to the addendum. This is a "watch out for" when bidding, it seems it will certainly add additional costs onto a bid where other competing coatings are already One Hour fire rated.
Click here for Maintenance Instructions for Mer-Kote Weatherdeck. We recommend that you use our Questions to Ask list that we developed that will help you understand the different deck coatings you might be presented with
Fiberglass Systems
www.alldeck.com www.excellentcoatings.com www.desertbrand.com 
There are quite a few manufacturer's who make fiberglass systems. In the early days of waterproofing decks, fiberglass was glued down to plywood by many manufacturer's, however today, only one still specifies fiberglass over plywood decks. The rest have adjusted their specifications to using fiberglass systems to renovate existing decks, such as Magnesite, Dex-O-Tex's Weatherwear and to repair cracked concrete slabs and walkways.
All-Deck is the one manufacturer we know of still specifying fiberglass over plywood; Desert Brand, Excellent Coatings, Pli-Dek and a few others do not. Improvements in resins have helped the bonding issues that can occur on plywood, however, large decks that would have some movement in it on a long term basis to feel secure to use fiberglass only.
Basically fiberglass coatings use a 3/4 oz. non-directional woven mat of fiberglass, bonded to a surface with a water resistant resin. A basecoat is applied over the fiberglass to provide protection, then a variety of finishes can be put over this. Fiberglass systems are self flashing on block and cement walls with proper attention paid to the details of lapping it up the wall and applying bonder/resin.
The great advantage fiberglass systems have is in their ability to restore decks and concrete with cracks in them. This can save costs in tearing out decks or sidewalks and re-pouring them. After any cracks are properly repaired, the fiberglass applied over the surface helps hide the cracks, preventing them from telegraphing up through the coating. We have seen this done with great success on pool decks, lightweight concrete decks poured over steel pan decks and even driveways!
We wouldn't be comfortable putting fiberglass over plywood decks; we have seen (and used) fiberglass systems to renovate existing decks that aren't leaking. An inexpensive alternative to tearing out an old system an installing a new one.
Click here for Maintenance Instructions for All Deck We recommend that you use our Questions to Ask list that we developed that will help you understand the different deck coatings you might be presented with
Metal Lath & Acrylics
www.waterproofingmaterials.com http://www.lifepaint.com/ * http://westcoat.com/ * www.excellentcoatings.com www.desertbrand.com www.merkote.com www.plidek.com www.endurokote.com
Metal lath and Acrylic coatings have become the coating to put on decks with all the major tract builders in Southern California. Heavy marketing efforts, SB-800, multi-million dollar settlements for water intrusion issues, builders seeking better materials that help them in their risk reduction efforts, all have combined to thrust these coatings into the limelight. At PCBC 2006, five manufacturer's were at the show marketing their metal lath decking systems to builders, architects and sub-contractors.With this system of galvanized metal lath, acrylic modified cements, fiberglass (depending on the manufacturer), and a pigmented sealer, these coatings resist the damage that it's competitors can't. Resistance to UV, cracking, use and abuse combine to make these coatings desirable for builders. Fiberglass is being used by several manufacturer's, with what appear to be superior results over the multi-layers of cements and sealers.
The diagram to the left shows a brand using a fiberglass layer. This type of system has an added advantage of preventing cracks that may develop from showing through the surface. The total of this system is greater than the sum of it's parts. Each layer performs a distinct function that all work together to provide a top quality deck system.
Metal lath systems, just like everything else, comes in varying levels of quality. Installer know how is critical, we've seen these systems fail, but it seems when they did, it was an installer error that caused the deck to fail.
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We recommend that you use our Questions to Ask list that we developed that will help you understand the different deck coatings you might be presented with.
Click here for Maintenance Instructions for Life Deck
Click here for Maintenance Instructions for Pli-Dek
Click here for Maintenance Instructions for Mer-Kote Shurdeck.
Click here for Maintenance Instructions for Desert Crete
Click here for Maintenance Instructions for Excellent Coatings
Click here for Maintenance Instructions for Westcoat Specialty Coatings
Vinyl
http://www.weatherdek.com
Vinyl decking is just what it sounds like, heavy duty UV resistant vinyl flooring like what you'd
buy for a kitchen floor. There are some differences of course, but the basics are all there. Popular in colder climates where UV isn't as big of a problem. Also used on docks sometimes.When vinyl deck coverings were first introduced, especially at seams on decks larger than the 12' width of the material, failures occurred. The old technique was to butt the seams together to keep a smooth seam. Now the technique is to lap over the materials by approximately 1" and heat weld them. Success rates have increased greatly with new techniques.
Vinyl coverings can be self flashing, the technique used is to simply roll the vinyl up the wall or down over the outside edge, securing the turned vinyl with bars and screws. Special attention to details such as these is critical to these decks properly performing. Maintenance consists of cleaning the covering quarterly with special cleaner.
Click here for Maintenance Instructions for Duradek We recommend that you use our Questions to Ask list that we developed that will help you understand the different deck coatings you might be presented with
Urethanes
www.tufflexpolymers.com http://www.polycoat.org/ www.carlisle-ccw.com www.deckote.com www.multicoat.com
www.polytuffus.comUrethane coatings are the ultimate waterproofing system; 100% impenetrable by water, they will keep an occupied space free of water intrusion. However, let people walk on it, use it with grills and tables and chairs on it and it's weakness becomes apparent; it can't resist much use and abuse.
There are basically two types of urethanes used for waterproofing decks; solvent based and water based. Tufflex is a well known water based urethane, utilizing plain water to set up and form a heavy layer of flexible materials. Pacific Polymers is a well known manufacturer of solvent based urethanes that cure by absorbing moisture in the air. After the waterproof layers are applied, sand is often broadcast into the pigmented sealer for grip.
Solvent based urethane systems in particular have been hit hard by tougher and tougher VOC standards in the state of California; they have been notorious for using chemical formulations that have links to known carcinogens. Today's urethanes are substantially different than those of years past. They require high amounts of maintenance to protect their tender under layers-think of a rubber band on the dashboard of your car on a hot day. It will become brittle and break easily with just a few hours of exposure. Urethanes have the same problem, lack of UV resistance. Their life depends entirely on being protected from UV with pigmented sealers-sun-block if you will to keep damaging rays from burning up the waterproofing layers. Just like your skin, when the sun-block stops being effective after a period of time, you start to get sunburned.
While inexpensive compared to other waterproofing, the long term maintenance costs and risk of being easily damaged outweigh the benefits of cost. An HOA would be probably better off with other alternatives.
We recommend that you use our Questions to Ask list that we developed that will help you understand the different deck coatings you might be presented with
Click here for Maintenance Instructions for Pacific Polymers (These instructions also apply to most other solvent based polyurethane coatings)
Click Here for Maintenance Instructions for Tufflex (water based urethane)
Click Here for Mandatory Maintenance Instructions for PolyTuff. We've never seen any as tough as this before! We wonder why they call it PolyTuff?
Pebble Bond Systems
http://www.epoxyproducts.com/riverstone.html (links to repairing Pebble Bond systems) www.lifedeck.com/2002/systems/pebblesystem/pebblehome.htmWhile not a true deck coating, we have included the Pebble Bond System here as we are so often
asked about these concrete coatings.Pebble Bond Systems, or "Pebbles in Epoxy", are all over southern California, much to the dismay of many an owner; who was apparently never told (or maybe it was down played by the salesman) that these concrete coatings need to be resealed frequently. The manufacturer's rosy 2-3 year resealing schedule doesn't work very well in the high UV exposure areas. The reality appears to be a 1 year, maybe 18 month resealing schedule, especially as epoxies VOC limits are affected, it will be tougher for them to get higher UV resistance- a true challenge to chemists.
Life Deck is the only manufacturer of a whole pebble bond system that we have found. The other link tells you how to fix these troublesome coatings, once the stones start breaking loose, it's bedlam when they get in the pool!
While these coatings are nice to look at, we think you should consider these systems very carefully before putting them on your concrete areas and don't ever be believe that they can be used to waterproof a deck over living space!
Click Here for information on repairing Pebble Bond Surfaces-This will open a new window that will take you to another site that is not related or affiliated with us but contains good information on these products.
We recommend that you use our Questions to Ask list that we developed that will help you understand the different deck coatings you might be presented with
Magnesite
www.DesertBrand.com
Another unique coating, Magnesite is the granddaddy of deck coatings. Made by Hill Brothers Chemical Company for over 60 years now, Magnesite is magnesium oxychloride cement, a non-combustible cement that dries very quickly, can be shaped into unique architectural details and has been put on millions of square feet of decks and walkways and stairs on buildings throughout greater Los Angeles, the Bay Area and beyond. It is seen everywhere as it is an architects design favorite. Magnesite is still sold today and though not as popular, is finding a resurgence in new applications for flooring solutions inside and out. Every manufacturer of decking drools at the thought of selling the amount of material Hill Brothers has with Magnesite.While it will last well over 30 years, performance comes at a price, which is maintenance. Weak points are at the areas where railings penetrate to the wood subfloor. Movement in the railings invariably allows the cement to crack a bit, leading to water penetration if not caulked. Cracks that appear on the surface need to be treated and the surface resealed about every 18 months.
Classic styling, durability and uniqueness will keep this product around for a while; keep up on the maintenance and it will last and last.
WARNING- Magnesite made prior to 1972 was manufactured with asbestos in it. If you are working on buildings built through 1974 you are advised to test for the presence of asbestos prior to removing any Magnesite. Contractors in California are REQUIRED to have a license for asbestos removal on any amount of area over 100 square feet. Exposure to asbestos is hazardous and continued exposure may cause cancer. Removal of Magnesite without mitigation could expose Building owners, HOA's and others to potential liability for exposing tenants, owners, visitors and workers to asbestos. Proposition 65 signs need to be installed if they are not already. Visit www.cslb.ca.gov for further information on asbestos.
Click here for Maintenance Instructions for Magnesite. We recommend that you use our Questions to Ask list that we developed that will help you understand the different deck coatings you might be presented with
