Don’t Break Your Deck, Waterproof it!

By March 1, 2016Tip of the Month
 Tip of the Month – March 2016

Don’t Break Your Deck, Waterproof It!


PNewrimeCo often finds that a commonly overlooked item for homeowners is the maintenance of their outdoor decks, which includes resealing and waterproofing. Most solid surface decks either have a slip sheet, liquid or cementitious waterproofing installed over the plywood substrate. These all require regular maintenance to ensure that the waterproofing maintains its effectiveness.4dbd6353-ede5-449e-9637-c77a9947616aOnce a waterproofing membrane has been compromised, it will only be a matter of time before the balcony or deck would need to be completely rebuilt based on water intrusion in the compromised area. Something that is helpful in preventing water intrusion is the introduction of metal flashings. These are installed around the perimeter of the balcony or deck to assist in waterproofing at corners where water can build up and compromise the structure.
It is important that you have the proper flashing on your deck, especially if you are located near the ocean. The closer to the ocean that you are, the more likely you are to have problems with eroding materials due to salt water. Salt water causes metals to lose their iron and begin to rust. This would be where you might consider using copper or stainless steel flashing materials to prevent rust and erosion from occurring. installed into the actual floor of the balcony or deck.
These flashings either hang over the sides of the balcony or are installed to rest against the walls in order to prevent water from leaking into the structure.
Another way to manage the flow of water off a balcony or deck is by the use of scuppers and or drains. Scuppers are used to allow water to flow through the wall and off the deck surface while drains are used to remove water from the deck.1007a1a8-9b38-4832-8b14-e111998901e5Any moisture in the waterproofing surface should be dealt with as soon as observed. Any moisture that seeps into the top surface of the deck may cause total failure of the waterproofing itself. Once the waterproofing is compromised, the substrate of the structure is more liable to become damaged.
It is important that the surface that is being resealed be cleaned thoroughly, which can be done using water and trisodium phosphate (TSP). This can be found at most local hardware stores. TSP is used for washing surfaces prior to painting, especially exterior surfaces. Liquid bleach is often added to TSP if there is mildew on the surfaces. After the surfaces have been cleaned, pressure washed and dried to remove dirt oils and contaminants you will be able to begin the waterproofing process.


When considering the regular upkeep and integrity of your balconies or decks, it is important to clean and reseal the top coat of the waterproofing. Two common detriments to a waterproofing system are water and ultraviolet rays. Outdoor decks are exposed to constant moisture and ultraviolet rays, causing them to be more susceptible to vulnerabilities in their waterproofing systems.
The cleaning and resealing of decks should be done every 3-5 years in order to preserve the integrity of the waterproofing membrane. Once the surface has been thoroughly cleaned and dried, an epoxy primer coat such as Westcoat EC-11 primer should be applied to the surface and allowed to dry. After the primer has dried, two coats of an acrylic top coat should be applied to the deck surface and allowed to dry.
While resealing your deck can help extend the life of your waterproofing, you may also extend the longevity by repairing the waterproofing membrane. This will ensure the integrity of your flashings and proper drainage of water off of the balcony or deck. Through continued and proper maintenance, your waterproofing system can last for the recommended period of time based on the manufacturers suggested lifespan.