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With careful attention to materials and structural details, it’s possible to build decks will last for decades and require minimal maintenance. However, decks are tough applications for building materials. The structural framework is exposed to the weather and often contacts the ground. Decking surfaces are exposed to sun, rain, and snow, as well as heavy foot traffic.
To add to the challenge, today’s treated wood is highly corrosive to Metal Fasteners. Modern building codes have responded with important safeguards for Building Safe and Durable Decks. Structural connections and proper flashing are especially important for long-term performance.
Despite the beating these materials take, more than ever we want decks to be low or no maintenance. This has spawned a vast array of Composite and Plastic Decking materials vying for our interest, with marketers sometimes promising more than they can deliver in the areas of performance and low maintenance.
Not surprisingly, consumers’ high expectations combined with the real-world performance of many relatively untested formulas has lead to more than a few consumer complaints. Several class-action suits have been launched against composite and plastic decking companies – mostly for premature failure from decay, cracking, or surface deterioration. In many cases, the problems were linked to quality control issues and only affected a specific batch of materials.
The good news is that manufacturers have had well over 20 years now to tweak their recipes and have learned to curb their marketing enthusiasm, emphasizing maintenance needs, product care, and realistic expectations of performance and appearance. Despite some notable exceptions, composites and plastics have proven themselves as durable alternatives to wood decking. In fact, non-wood decking now accounts for almost 50% of the decking market.
For those who want real Wood Decking, but without the annual ritual of cleaning and sealing, Tropical Hardwoods offer a excellent alternative. Prices have come down, making these products competitive with high-end composites and plastics.
The leading choice in high-end hardwoods is Ipe, but several other species such as cumaru and garapa offer similar performance at lower prices. Ipe and similar species provide natural resistance to decay and insects like old-growth redwood, but with a density and hardness that can provide decades of service with minimal maintenance.
Porches are basically decks, with partial walls and roofs – at least that’s how they a usually built today. To simplify construction and reduce costs, many porches use the same methods and materials as exterior decks with a roof overhead. Since porch floors get less exposure to rain and sun, they are less prone to crack and warp and can, therefore, be built with less durable materials than open decks. For example, painted tongue-and-groove ¾-in. flooring is common on older porch floors. Today standard exterior decking with drainage gaps is more common in porches as it is more forgiving and requires less maintenance.
A. Walker says
Can I Fasten the Bottom of Deck Ledger Directly to Concrete?
I have a wrap around deck on my house. In front the deck is at a height of 10’ and measures 12’x68’. In the rear and side deck height is 3’, all built using pressure treated 2×6 lumber on a 45° angle.
The house is a 68’x30’ double wide modular with a 3-layer 2×12 box joist. It sits on a 10” poured concrete wall with double rebar for 80% of the perimeter stud wall for the remaining 20% in the front. This all sits on a 2’x2’ poured foundation with a slab floor design. The home was originally an “underground” design with a front walk-in built in 1981 and left to me by my dad when he passed in 2014. When we began remodeling we found complete termite infestation so we used the exterior poured wall for the “foundation” and dropped the modular on top, effectively turning the old house into a basement.
I recently discovered that the ledger is only attached to the Box Joist of the home at the top 4” using common deck screws. I assume this is because the ledger only overlaps the Box Joist by about 4”, below that point it is over the poured concrete foundation. I also discovered that the vinyl siding was not removed across the front when the deck was built. I’m searching for solutions that don’t require removal of the deck or detaching the deck from the house.
I’ve considered drilling through the decks rim joist and the concrete foundation and using 1/2”x 12” bolts maybe every 2’ around the perimeter of the previously unattached portion of the ledger. With a 3-layer box joist on the modular, I figure I could use up to about 5/16”x6-8” Timberlock screws around the perimeter to replace the existing deck screws. This should adequately secure the ledger. As for the vinyl siding, I know it’s not preferred, but does it need to be removed ? There’s no way to do so without removing the ledger from my perspective.
buildingadvisor says
Attaching a ledger partly to the home’s rim joist and partly to the concrete foundation is an unusual detail but should work fine with the proper flashing and connectors. Do not place fasteners in the top 2 inches of bottom ¾ inch of the ledger.
For connecting to the rim joist, you should use timber screws specifically approved for deck ledgers such as Fastenmaster LedgerLok or Simpson Strong-Tie SDWS Timber Screws (.022 in. diameter). Choose screws that fully penetrate the home’s band joist. Spacing is similar to ½-in. lag screws, but check manufacturer’s specs and local codes for more accurate guidelines.
For attachment to the concrete foundation, you could use through bolts as you describe, with large 3×3-in. or 4×4-inch square plate washers on the interior. However, it would be easier to use concrete expansion anchors. Use 1/2-inch anchors embedded into the wall at least 2-1/2 in. or as specified by the manufacturer.
The ledger should be protected by a durable metal flashing that extends under the new siding. You can read about ledger flashing as well as ledger attachement details at this link.
The vinyl siding, as I understand it, should not present a problem as long as you are able to effectively flash the ledger to keep it dry along the top surface.