Rooftop Deck Maintenance
The how-to guide for care and maintenance of your rooftop deck
(Stub-ins & shut-offs at roof for AC/Heat pump)
Regardless of your roofing materials beneath your decking surfaces the mentality for caring your your rooftop deck should be similar to the mentality of caring for your roof. Why? Because your rooftop deck IS your roof (or installed on-it)!
(Routinely maintenance beneath your roof-top deck. Ensure debris does not create dams)
The primary concern for home inspector while inspecting a rooftop deck is the roofing membrane itself and any appurtenances that continue through it. There are many different kinds of roofing materials that can be used under a rooftop deck; TPO (thermal-plastic olefin), Torch-down, galvanized or spantex coated metal-sheets and Rolled roofing are the most common (and are also in order of longest-anticipated-lifespan to shortest). You inspector should help you to identify the anticipated total life-expectancy from new and an observed approximate or exact age, if known.
Regardless of the type or anticipated remaining life-expectancy; maintenance and upkeep are the keys to lesser-headaches.
Observe: As the homeowner, you should inspect your rooftop deck yearly, yourself. Check areas around the deck (if possible) for a sightline on what’s going on beneath the decking surface. Many times the decking surface may be trex-alike (man-made) which show very little wear, but the furring-strips (or attachments under the decking) are made of pressure treated and/or sometimes natural wood. It is important to understand that natural-wood materials beneath the decking surface are likely to be the first area requiring maintenance or replacement because they see a) less sunlight and b) more standing-water exposure. Both conditions yield deterioration to the natural products.
(Natural wood supports (furring strips) supporting weather decking showing signs of decay (deferred cost))
Many roof-top decks are build without easy access to the under-side of the decking surface. Our recommendation: when installing-new or performing maintenance on rooftop-decks; implement an easy-access system. Choose a hatch-design (hinged-access) or use screws instead of nails; making it easier to remove individual boards or sections of boards to clean roofing materials beneath. Remove any organic or inorganic debris which could dam water or keeps it from freely-flowing towards the gutter system on a yearly basis. Ensuring proper drainage from the roof will lessen the chances of a leak due to water sitting/ponding in any given area.
The easiest way to clean under your decking surface is to use a leaf-blower or compressed air – open the decking surface using a hatch or by removing boards. Blast all the debris trapped beneath the deck outwards towards the gutter side of the home. Depending on the surface (non-granular coated surfaces) you may be able to use a power washer. If your unsure of your roofing type; or appropriate methods of removal; contact a local home inspector or roofer for tips & tricks as well as to-do’s and do-no-do’s. While you have the area exposed, use a flashlight and observe as much as the underside as possible, scanning for any imperfections or damage that may lead to more-serious repairs down the road. Remember: roofing-upkeep is always cheaper than fixing water damage caused by lackluster-upkeep.
Use mild, non-bleach detergents to clean moss/mildew/bio-products off roofing systems naturally by changing the PH balance of the water moving across the roofing material. This should also be performed yearly.
Correct: Any damage to the roofing membrane promptly. A common issue we observe is people treating/maintaining their rooftop deck like a deck; when it is in fact: a roof. Moving furniture or installing exterior features in these areas should be done with care and consideration commiserate with a roof. If you damage the surface, you should contact a roofer to evaluate the damage and make corrections to the area with haste. Allowing damage to this area to go untreated will leave the homeowner open to significantly higher risk of leaks and failures.
Keep parapet caps well sealed throughout the years. Regardless of how water-tight the parapet caps appear to be sealed or promises by the builder, we recommend inspecting and touching-up sealant at all abutments, corners or connections-to-other-products, yearly. Remember: the the parapet caps are essentially the roof-section that covers the top of the walls. Proper upkeep and maintenance can save you thousands in repairs throughout the lifetime of the home.
Keep scuppers, gutters and shed-transitions clear of debris. So: you’ve cleaned out the under-side of your deck, awesome! Where has all the debris gone? Into the gutter-system! So keep these areas freely accepting water throughout time also. Backed-up gutters have a high likelihood of causing water damage to your home. An old home-inspector adage here in the PNW is “your house will rot from the gutters inward”. We say this time and time again, and despite popular belief; it’s not because we love the sound of our own voice (though mine is particularly beautiful).
Roof replacement: “yes”, even though you have a rooftop deck, you will still have to replace the roofing products beneath it, eventually. Anticipate and plan accordingly. As you can probably imagine, replacing a roof with a deck over it will cost significantly more money. You’ll have to remove the entire decking system prior to starting the job. This can cost significantly more time and money due to the additional workload. Plan accordingly and plan early to curb the gut-punching estimate you may receive depending on your very-unique set-up. Partner with a licensed roofer who is familiar with working with your specific type of roof. If you call and say “Hi, I have a TPO roof under my roof-top deck that needs to be replaced” and your pro doesn’t immediately say “we can help with that”; it’s best to keep looking for a different professional who’s familiar with your specific type of system.
Placement of potted-plants or roof-top gardens: Always raise your installed features above the surface so you can observe whats going on beneath them. Potted plants should be installed on bricks or concrete lifters to allow drainage beneath the item and allow for the observation of organic matter that’s likely to accumulate beneath. Rooftop gardens should also be raised and cleaned beneath frequently (please note; check with a general contractor/engineer before installing anything significant on a roof to ensure the system has the proper support necessary to accommodate the additional load).