In order to further your education on the subject of decks, here is a picture gallery of a typical deck installation. Please note that this is not to be construed as specifications for any job, material or manufacturer, consult your architect or construction manager for advice.
What we will take you through are the essentials for a good, leak free flashing and deck installation, utilizing a metal lath and acrylic concrete system. In all cases, but for decks in particular, proper flashing techniques are essential. Flashing must be installed in a weatherboard fashion, allowing for water to shed away from the building. Reverse laps in flashing and contiguous building materials, especially building and stucco paper, contribute to many leaks. Proper sequencing of the job is essential, scheduling the trades to coordinate this work can be difficult but must be done. You are advised to consult ASTM E 2266 44 Standard Guide for Low Rise Construction To Resist Water Intrusion for further information.
Many installers are paid these days by piece work, or how much can you do in a day? They rush to get your job done in order to make as much money as they can. I can't blame them...but I do blame the owners of these types of company's. To often in haste to get done, critical steps are glossed over, missed or not detailed as well as they should.
Often times decks are blamed as the source of a leak into the home when actually the leak is occurring from items near the deck-hose bibs and exterior electric boxes are the two most common items that leak. All penetrations must be flashed and caulked properly. Railings and walls are the next two most common items to leak, again, usually because of poor flashing and wrapping techniques. Recent technology utilizing Thermal Image Photography reveals these defects without destructive testing. A good page to see this in action is found at a contractors web site, The G.B. Group. This site shows deck and balcony leaks for the demonstration-testimony to the many claims and problems still occurring with decks?
For penetrations above the deck, I insist my contractors use QuickFlash Weatherproofing Products to provide me and they assurance that the penetrations won't be a source of a leak. Electric boxes, water and gas pipes, AC lines, just about any penetration through a building has a flashing device for it at Quickflash. For about $10.00 each installed, it's cheap piece of mind. So don't be cheap. Put them on before closing the building up!
See Quickflash's entire catalog of flashing devices by clicking here.
“Picture Courtesy of Ron Webber, Picture by Bill Leys Pro-Coat Systems, Orange CA” Central Coast Waterproofing Deck ready for flashings to be installed. All edges and walls needs to be flush, plywood is nailed or screwed down, outside edge of deck just needs a stucco stop (3/4" x 1 furring strip) nailed on for fascia flashing to be nailed over. | |
Slope needs to be checked. One quarter inch per foot of fall is required by most manufacturer's (1" in 4') Anything less and water may puddle on the deck and may cause problems. Your warranty may be voided if proper slope is not provided for. |
Caulked lap at fascia, or drip edge. Lap extends over 4", a good sign. Four nails through the edge of the lap and this joint is ready for applying waterproofing over. |
Here is a door pan installed. Note the lip in the background to keep water from leaking into the house under the threshold. A generous leg allows the sheet metal man to lap his L metal over properly. Generous use of polyurethane caulk provides assurance that this joint is tightly sealed. | A well sealed corner can be a tough detail to properly flash and seal. Attention must be paid to, and enough time to allow proper installation and detailing. |
Here is a well sealed joint with the lathers paper down to the weep screed, which has been installed over the flashing running up the wall behind the paper. All contiguous building materials must be installed in a weatherboard fashion and maintained so to remain water tight. Water entering under an installation from contiguous building materials will not be warranted against. | Here an installer is stapling down 2.5# metal lath to the plywood. The lath is stapled with apx 20-25 staples per square foot. Note the taped plywood seams. |
Acrylic modified cement is troweled into the metal lath, covering it completely. |
3/4 oz. Non Directional Fiberglass is then laid over the cement and a resin is rolled through the glass, bonding it to the surface. |
A screed coat is troweled over the fiberglass and then a knockdown texture was sprayed out for slip resistance. |
For even more pizzazz, a tile pattern was done on this deck. |
Other Items That Sometimes Are a Part of Your Deck System
These are also essential and careful attention must be paid to properly detailing these items. See the photographs and details below.
A post has been kerf cut to accept the flashing. Periodic maintenance must be performed, caulking the joints and keeping the post well sealed with paint or stain. Reject any wood posts that have a split in them, these openings will let water penetrate to areas below. |
Making it easy for the lather (stucco) to install his building paper in a weatherboard fashion is this large piece of sheet metal that will allow paper to drop over the metal and and be slipped up underneath it too! |
Scuppers are a big problem area if not properly installed and caulked. The scupper must be flashed on the inside and outside as well. | |
