Comparing Rooftop Deck Material Options for Your Philadelphia Remodel

Rooftop decks provide peaceful outdoor spaces where family and friends can recharge and reconnect at the end of a long day. Decks also provide opportunities to host unique events like parties, barbecues and just soaking up the sun. Whether you are creating a new deck or upgrading your existing rooftop deck, learning what materials are best for a rooftop deck is an essential step in your design and budgeting process.

While your contractor may be able to provide some help to find the right material for your deck, it's also important to be educated to ensure that you are ultimately happy with your choice. Invest a little time and become familiar with deck materials and their performance history. Find reliable sources for information on the features and price points of different products. Do your own research, balance the costs, and consider the pros and cons of each material.

We'll be covering the following decking materials for you:

1. Pressure Treated Decking
2. Cedar Decking
3. Composite Decking
4. Plastic Decking
5. Ipe and Massaranduba Hardwood Decking
6. Aluminum Decking
7. Fiberglass Decking

Decking Cost vs. Durability and the Janka Hardness Scale

We have categorized each option referencing a Janka Hardness Scale. The Janka scale range spans from 300 for cedar decking all the way up to 3700 for Ipe decking (in the mahogany family).

Why should you care? Because a higher hardness rating equates to higher durability. Every time your kid's friends drag deck chairs across the grain on your wood floor, you'll be happy you learned what a hardness scale was for. Also, don't forget about your mother-in-law's spiked heels - those are the worst!

It's worth mentioning that this article explores just the finishing materials for decks. Deck structures (under the finishes) are almost always made from pressure treated framing lumber, which is generally the same as our first option; pressure treated decking lumber. The difference between the two treated products is negligible - only the dimensions are different.

Below is a list of popular rooftop deck options including the pros and cons of each. For your convenience, we have organized them in order of their purchase price, ranging from lowest cost ($) to highest cost ($$$$).

Pressure-Treated Decking

Pressure-treated Southern yellow pine is a chemically treated, weather resistant wood used in 80% of all decks built in the US. Sometimes referenced by the brand name "Wolmanized", pressure treated decking color starts as a greenish tone when fresh or "wet" and becomes more yellow after 6 months (as in the photo). After a few years in the sun, pressure treated wood becomes silver-grey.

You can periodically clean off the silver color and get back to the yellow tone with the help of a pressure washer, followed by an exterior grade penetrating sealer. This type of maintenance is typical for natural wood decks and required to achieve the full potential lifetime value; about 15 years. A poorly maintained pressure treated deck will often begin to splinter and a pressure treated wood splinter in your foot is not fun. This deck is not suitable for bare feet when the deck is newly installed because of the toxic chemicals used.

Many homeowners prefer pressure-treated wood for its affordability and good durability. Pressure-treated decking does have some disadvantages, so it's important to understand what you're buying before you commit.

Pros:

• Cost: $ - This material is the least expensive decking option.
• Installation - Pressure-treated lumber is readily available, simple to install and repairs are easily matched.
• Environmental - Good. Pressure treated lumber products are locally sourced, sustainably grown and are renewable resources although the copper arsenic preservatives are not green. 
• Appearance - Pressure treated deck material has a universal appeal for it's natural grain. It can be stained after the wood dries out (approximately 6 months after purchase). Pressure treated decks begin to show their age after 5 years, but a solid stain can help keep it looking fresh.

Cons:

• Durability Rating: 870 - Pressure-treated lumber has a lower hardness but with some care, it will perform in normal weather conditions. Use a harder deck product if you expect heavy use (like high heels).
• Service life - 10 to 20 years. Other materials such as composite or plastic decking will have a longer life span than pressure-treated decking.
• Maintenance - For the first 5 - 8 years little maintenance is required unless it is in shade or a damp location under a tree canopy, in which case annual pressure washing will keep mildew from growing on the surface. The preservatives in pressure treated wood will begin to wash out after 8 - 10 years after which time, we suggest a thorough bristle brushing and a solid stain or deck preservative treatment. 

Cedar Decking

Cedar is an attractive wood decking solution, best suited for lower traffic or less frequent use. With rich color tones, affordable price and durability, cedar is an option you should consider but it is a soft wood, so high heels are no good.

Cedar tends to last well as it is naturally resistant to rot, insect attack, and moisture. Cedar decking requires low to average maintenance and doesn’t warp or split as easily as pressure treated decking. This product begins life with beautiful light red tones, although if it's not regularly maintained and sealed, cedar decking will become a silver grey (which can also be attractive).

While some homeowners love the knotty appearance of the standard grade cedar deck option, some find it more attractive after its sanded, stained and treated with a beautiful finish. 

Pros:

• Cost: $$ - Cedar deck material is an inexpensive decking option.
• Installation - Cedar decking is generally available from lumber yards, simple to install and repairs are easily matched.
• Appearance - Cedar deck material has a beautiful rich look with a rich redish natural grain although the standard grade has frequent knots although it can be purchased in a clear grade for an additional premium. This material will turn grey after the first year, and if desired, a solid stain or sealer can help keep it looking good.
• Environmental - Excellent. Cedar lumber products are locally sourced, sustainably grown and are renewable resources with a relatively low carbon impact.

Cons:

• Durability Rating: 900 - Cedar decking has a low hardness but with some extra care, it will perform well in normal weather conditions. If heavy wear is expected, try a deck material with a higher rating. Keep in mind that home supply stores may carry a softer grade of cedar decking which, although attractive and inexpensive, may not be as durable.
• Service life - Average at 15 to 20 years. Cedar is naturally rot and insect resistant. Other materials such as composite or plastic decking will have a longer life span than pressure-treated decking.
• Maintenance - Not much maintenance is required for cedar unless it is in a shady area. Cedar decking has natural oil that keeps most mildew away but it may discolor with age. Pressure washing, staining and a quality sealer will extend cedar's lifespan.

Composite Decking

Composite decking is long-lasting, low-maintenance and attractive. Higher -quality composite decking looks almost like real wood, even after many years of exposure to the elements. Unlike pressure-treated wood, composite decking needs no sealing, staining, refinishing or painting although mildew will grow on the deck surface, especially in the shade. Composite decking is much more valuable than pressure-treated decking because it is so easy to maintain. Unfortunately, this also means that composite decking is more costly.

Pros:

• Maintenance - Composite decking requires little maintenance other than pressure washing every 1-2 years.
• Appearance - Many composite decking features include imitation wood grain and a few color options that have great appeal. Ask for samples from different manufacturers.
• Environmental - Composites are normally made a combination of recycled plastic and wood fibers and so are environmentally friendly.
• Installation - Quality composite decking is generally available from quality lumber yards, it is simple to install although repairs may NOT be easily matched if the manufacturer has changed the color tone since purchase.
• Durability Rating: 1400 - Moderate hardness. Composite decking can last for 20 - 25 years, particularly if the decking is of good quality.

Cons:

• Cost $$ - It may be worth the moderate cost increase over pressure treated if you will live in your home for more than 10 years, but composite decking options can be somewhat expensive.
• Service Life - Expect 15 to 25 years depending on location and manufacturer. Beware of low-quality composite decking from box stores. Lesser composite options will often warp, discolor or sag.

Plastic Decking

Plastic decking can have a strong reaction with homeowners. Designers and homeowners either love it for it's lasting appearance in the elements, or dislike it because it seems like an unnatural material. Either way, it has been increasingly popular and worth considering. For most homeowners, it simply comes down to an aesthetic decision because the longevity is hard to beat.

Looks aside, plastic decking is waterproof, requires little maintenance, and is  resistance to insects, mold, mildew, and rot. Compared to wood and wood composite, plastic decking is easy to clean and less susceptible to staining and fading. For these reasons alone, we have found the interest in plastic decking continues to grow as homeowners desire low-maintenance, permanent decking solutions that look just as good 20 years after installation.

Pros:

• Maintenance - Plastic decking options require almost no maintenance. Washing can be accomplished very easily.
• Appearance - There are a number of plastic decking manufacturers with products featuring imitation wood grain and some colors with a reasonable likeness to wood. Detractors will say that plastic decking looks fake so make sure you do your homework and pick the best looking color and finish.
• Installation - Plastic decking is generally available from lumber yards, it can be tricky to install if you don't plan it out correctly since some profiles require a unique design layout in order to resolve edge details. Repairs may not match if the color has changed after the initial purchase.
• Durability Rating: 1400 - Moderate hardness. Composite decking can last well with only minor wear marks, particularly if the decking is of good quality from a respected manufacturer.

Cons:

• Cost: $$$ - A good looking, high performing plastic deck material is more expensive than other options.  If you want your deck to look good in 20 years, seriously consider this option.
• Service Life - 25 to 30 years with a quality manufacturer.
• Environmental - Plastic decking is generally not a recycled plastic material but then again, it should last twice as long as most decking alternatives, so perhaps it will not go to a landfill as early.

Ipe and Massaranduba Hardwood Decking

These hardwood decks have unparalleled beauty at the time of installation. Ipe and massaranduba are in the mahogany family of hardwood and are lovely to look at and touch. The disadvantage of Ipe and Massaranduba, aside from the upfront cost, are the maintenance costs. Imagine a lovely piece of wood furniture that is left out in the rain! If you want this decking material to continue to look amazing, you will be saddled with high annual refinishing costs (pressure washing, sanding and re-sealing expenses). 

Ipe and massaranduba has an unbeatable look but a high overall cost. Ask your contractor about various hardwood options, but either be prepared for maintenance or be ready for a weathered, grey appearance. Hardwood can also splinter, especially if it is allowed weathered to weather without maintenance - so be careful with bare feet!

Pros:

• Durability Rating: 3700 - Ipe is slightly harder than massaranduba, but they are some of the hardest wood decking options widely available.
• Service Life - 20 to 30 years, depending on maintenance attention. Ipe and massaranduba are both rot and bug resistant and hold up very well structurally. All wood decking options will begin to show their age in a faded, greyed appearance after a few years.
• Appearance -Oustanding! Rich mahogony tones for the first few years. This look takes effort to maintain. 

Cons:

• Environmental - Hardwood lumber products are generally green when they are grown locally. Ipe and massaranduba farms are located in South America so the carbon footprint is relatively high due to shipping costs. On the plus side, wood decking is biodegradable and renewable. 
• Installation - As you might expect, extremely hard, dense material is more difficult to cut. Expect higher installation costs due to longer installation times and more wear on cutting tools.
• Cost: $$$$ - Ipe and massaranduba are some of the most expensive decking products available.
• Maintenance - Wood decks demand greater attention and care from homeowners, including sanding and resealing every few years to protect the deck from water damage and to help maintain its appearance.

Aluminum Decking

When designing new or replacing existing decks, homeowners often initially think of wood decking options, yet aluminum decking can be a near-perfect solution for your deck! Aluminum decking has a powder-coated finish with the potential to last longer than any other deck material. It won't rot, rust, warp or crack, it's highly resistant to mold and is also slip-resistant. 

Not only do parents love aluminum decks because they don't splinter and require almost no maintenance (unlike wood or composite decking), but we have found that barefoot kids and pets love aluminum decks too. Since aluminum reflects heat more efficiently than wood or composite materials (which tend to absorb heat), an aluminum deck should stay cooler in direct sunlight. No need to run to grab your flip flops! It's ok to walk barefoot on an aluminum deck as you won't burn the bottoms of your feet!

Even though aluminum decking is the highest cost, it gets our highest marks for value because of the fact that the decking looks just as good on the day it's installed as on the day you sell your home, 25 years later! Add that to the fact that you will likely have no maintenance or replacement costs for 30 - 40 years and you can see why we like it.

Pros:

• Maintenance - The only maintenance you'll need to worry about is occasional light pressure washing (if shaded or under a tree canopy).
• Durability Rating: 5000 - This is higher than most decking options and it is unlikely that normal use would cause any significant wear over the lifetime of aluminum decking.
  
• Service Life - 30 - 40 years if sourced from a high quality manufacturer. In fact, aluminum decking should not be installed over conventional pressure treated framing if you expect to maximize the lifetime value of this product. Instead, consider building your frame using aluminum or other non-ferrous rigid framing.
• Environmental - Surprisingly, aluminum decking is perhaps the greenest option on our list because it is both renewable and recyclable. More importantly, it can last 3 times as long as other decking options.

Cons:

• Cost $$$$ - Aluminum is more expensive than PVC, composite, cedar, PT lumber and most hardwood deck material. On the plus side, your maintenance is lower and the deck may not need to be replaced in your lifetime.
  
• Ease of Use - Cutting the aluminum is more difficult, and a carbide-tipped tools are a must. It is more difficult to repair and the design layout must be completed by someone familiar with the product.

Fiberglass Decking

Fiberglass is not just for high-end shore houses anymore. Traditionally only used when extreme weather proofing was needed, fiberglass roof coatings designed as a walk-able deck surface are an attractive cost saving option when incorporated into a new roof structure as a primary water shedding roof surface for your home.

Fiberglass deck surfaces are generally not an option for a traditional deck replacement project because they are normally specified during a larger construction project as a substitute for the actual roof surface of your home on flat roof structures found in cities like Philadelphia.

Pros:

• Service Life - 25 to 35 years with regular maintenance. Fiberglass decking can withstand extremely harsh weather such as hailstorms, snowstorms, and high winds.
• Maintenance - Fiberglass decking used in the correct application is a fairly economical option that requires very little maintenance. It should be inspected by a certified fiberglass installer every 2 years though because the walk-able fiberglass deck surface is also your home's only roof protection.
  
• Durability Rating: 4500 - This is about as hard a deck surface as you could hope for. That being said, fiberglass deck surfaces are also protecting your home as a primary water barrier (roof membrane) so you should not use this deck surface regularly without some kind of protection such as rubber mats or some type of outdoor carpeting.

Cons:

• Cost - Fiberglass decking installation is expensive but designed as part of a new home addition or new roof structure it can actually be cheaper than the combined cost of a separate roof and a conventional deck frame suspended over a traditional roof.
• Environmental - Fiberglass decking installation involves a great deal of high VOC off-gassing and it is not a renewable or recyclable material. On the plus side, it is an extremely light product and reduces the need for conventional decking material installation.
• Ease of Use - The actual mixing of fiberglass is very difficult and should be left to a certified installer. Fiberglass installation must be completed to exact specifications in order to perform both as a walk-able surface and as a home's roof protection.

Hidden Deck Fasteners for a Clean, Sleek Installation

One last thought! Keep in mind that the least expensive method of decking installation is to connect the deck to your substructure (deck framing) is through the face of the decking material itself.  This will create hundreds of small but visible holes with screws in the walking surface of the deck. Instead, we suggest you consider one of many hidden fastener systems for decking installation. Hidden deck fasteners are compatible with many deck materials (aside from aluminum and fiberglass).

Composite decking fasteners are also available with a trademarked dual- screw design which partially covers the holes after they are screwed into the face of the material. This saves the cost of installing the hidden deck fastener and may be an acceptable option for you, but make sure that you understand the finished appearance that you are getting before you sign off on your selection and installation method!

Installing a New Deck on Your Philadelphia Rooftop? 

A well designed home improvement project like a rooftop deck can add value to your home, apartment, or condo. However, it's vitally important to ensure that your deck is properly planned, permitted and well-constructed using the right materials. Your rooftop design must be engineered in order to be capable of bearing the weight of your deck, and educate yourself about the decking material options, installation methods and future maintenance. Be sure to order samples before you decide!

When deciding which contractor to use for this project, ask them about their previous experience, look at their portfolio, discuss the design and construction process and get references!