DeckExpert.com answers your questions about deck waterproofing methods and materials for only $25.00.
“I am building a new roof deck as part of a full house remodel and I found you when researching my waterproofing options. My builder is suggesting hot mop, but I am not sure it is an appropriate option for a deck. The deck is on the plywood substrate and will not be heavily used (it is primarily there due to city’s set back requirement), but I still want to make sure that it can withstand light use. We are planning to install modular deck tiles on top of the decking surface.” Marat B San Francisco CA
Thanks for writing; you’re wise to have done some research and raise doubts about “hot mop” for waterproofing a roof deck.
Today’s modern deck waterproofing systems from our manufacturer’s provide all in one solutions to your waterproofing dilemma. The decking/roofing systems under Division 7 Pedestrian Walking Decks are all tough durable membranes that can be finished to look like wood, tile, stone etc.
Alternatively, if you want a wood deck on pedestals above a waterproof surface, walking deck systems are still your best choice. The coatings can be installed and then pedestals can be placed on top of the waterproofing and a deck system built on top. With this method you should allow for being able to remove the decking to clean the waterproof surface periodically of debris. Extra slope over the minimum code required 1/4″ per foot may help flush debris off. I would suggest draining off roof edges rather than roof deck drains (ThunderbirdProducts.com) as debris may clog drains at the worst possible time. If you opt for drains, use a minimum of a 3″ drain and 3″ ABS pipe.
If you review our site, you’ll find lots of information and advice that should be useful in your quest. Make sure to read, understand and meet all requirements for a waterproof deck system and always use Best Practices to go over and above code which is just a bare minimum. For instance, use 1 1/8″ plywood over the minimum 5/8″.
Good luck with your project, Bill Leys The Deck Expert
The balcony that collapsed in June of 2015 in Berkeley, killing 6 and severely injuring 7 other Irish students has been found, after analysis by forensic scientists, to have been constructed improperly. As a result, the Contractors State License Board has filed through the Attorney General’s Office an accusation against Segue Construction, the general contractor.
The allegations are serious, not following plans without an architects approval will land you in hot water with CSLB. It has also resulted in 6 dead people and 7 injured. The weight of that alone would crush me, yet these people running Segue are conscienceless snakes that sought to blame the victims. How do they look in a mirror?
The accusation lists out specifically the contractors failures, from not using pressure treated materials, to using OSB board where their project manual said it was specifically not acceptable, to failing to cover and protect the deck until it could be waterproofed to failing to waterproof it properly.
Read the accusation by clicking here. Alternately you can read the specific allegations below. The accusation is a public document and the CSLB has posted it as a public service to help warn consumers, as they feel that Segue is a threat to the public. Segue is afforded due process and can defend against the accusation, including even if/when their license is suspended or revoked. Another case I’m familiar with has dragged on since October of 2013 and still proceeds today so justice may take a while here too.