Building a deck on your own is a satisfying experience. You have complete control over every aspect of the process, including when to work, how your budget is allocated, and all creative decisions. When you’re completed, you’ll be reminded of your efforts every time you entertain or gather with friends for a BBQ. Having said that, building a deck on your own involves careful planning and research.
Laying deck joists is a critical component of deck installation. When installing your joists, various aspects must be considered, including the size required and the amount of space required between each one. We’ll examine the purpose of decking joists and frequently asked questions about joist installation in this article. Additionally, we’ll provide step-by-step directions for quickly and easily installing your deck joists.
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What is the Definition of a Decking Joist?
Before beginning to install any type of decking, you’ll need a firm, flat surface to work on – this is where your deck frame comes in. A decking joist is a repeated board that acts as the structural basis for your deck and is attached to the ledger with galvanised joist hangers. Typically, joists run parallel to the house, whereas the top decking runs perpendicular to the house. Each substantial piece of your deck must be supported by joists. Otherwise, it will be structurally unsound and may eventually bend or buckle.
While joists can be made of a variety of materials, including steel, we normally choose pressure-treated lumber when paired with composite decking. Joist boards and all other necessary building supplies are available in-home improvement and hardware stores.
Frequently Asked Questions About Installing Decking Joists
In addition to size and spacing, there are other aspects to consider while constructing and installing joists. Incorrect board measurements or spacing distances might jeopardise the structural integrity of your building and may even violate some local building laws.
To assist you, the following are answers to some of the most often asked concerns concerning installing and using DPC on decking joists:
1. Which Joist Dimensions Do You Use for Decking?
Joist boards are available in a range of sizes, from 2-by-4 to 2-by-12. You can select the size that works best with the overall design and proportions of your deck. The larger the deck, the greater the joists required. Two-by-6, two-by-8, and two-by-10 joists are frequently utilised. Using the typical spacing of 16 inches between joists for residential decks, a 9 1/2-foot deck would require two 2-by-6 joists, an eight-foot deck would require two 2-by-8 joists, and an eight-foot deck would require two 2-by-10 joists.
If you’re unsure of the proper size wood to utilise for your decking structure or the proper size joist boards for your project, call a professional deck installer.
2. How wide should the joists on a deck be?
The width of your deck joists should be determined by the distance between the beams or the distance between the beams and ledger. Always check your local construction codes to determine whether there are any restrictions on the dimensions of deck joists. If nothing is specified, you can use the following rules for 16-inch-apart joists:
- 2-by-6 joists: Joists should span approximately 9 1/2 feet.
- Joists 2-by-8: Joists should span 13′.
- Joists 2-by-10: Joists should span 16 1/2′.
Are you unsure of the proper size of wood to utilise for your decking frame? Additional resources include an online deck span and spacing calculator, which takes into consideration the size and spacing of your joists, as well as the type of wood you’re using.
3. How Should Deck Joists Be Spaced?
How far apart should deck joists be spaced? In North America, residential deck joist spacing should be between 12 and 16 inches apart, or as required by local building codes. The majority of decks require 16′′ spacing between the decking and 12′′ spacing for unique uses such as stairs or commercial constructions. For precise instructions, refer to the installation guide included with your decking. The International Residential Code’s Table R507.7 gives additional information about the standards governing the maximum joist spacing for decking.
If you’re placing composite decking directly on top of your frame, each joist requires at least 1 1/2 inches of support. If your deck contains any butt joints – the intersection of two deck boards — you must install a sister joist in this position. Additionally, if you intend to utilise a breaker board to separate your deck rows, you must construct a ladder joist.
If you are remodelling an old deck, always verify that the joists are correctly spaced in line with current rules and requirements, and replace them as necessary.
4. How far can the deck joists protrude beyond the beam?
When a joist extends beyond a beam, this is referred to as a cantilever. The maximum safe distance for a cantilever is determined by a number of criteria, including the type of lumber used and the joist size and spacing. On a deck, cantilevers should not be more than one-quarter the total length of the joist and should not be more than three times the width of the joist, respectively. To remain compliant with building rules, an overhang on a deck must meet each of these characteristics.
Example: If you are using southern yellow pine lumber for your joists, the maximum permitted cantilever overhang is 3 feet for 2-by-10 joists spaced 16 inches apart and covering a total distance of 12 feet.
5. Which Lumber Should Be Used for Joists?
You’ll want to utilise ground-contact wood for the framing of your deck. Douglas fir and southern yellow pine are two of the strongest wood species for joists. When choosing timber, look for boards that have a “No. 2” or higher-grade rating. If you use anything less than that, your boards may not be strong enough to sustain a deck.
If you want to work with pressure-treated wood — which is highly advised — be certain that your boards are completely dry and acclimated before you begin your project. In some areas, the amount of precipitation or the relative humidity might dictate the sort of lumber to pick for an outdoor deck. Consult a lumber technician or a professional deck builder for recommendations tailored to your environment.
Bear in mind that boards are sold in even lengths, which means that constructing an odd-numbered deck will involve extra cutting and lumber waste. For instance, if you’re building a modest 11-by-11 deck, you’ll need to trim all of your lumber to fit, whereas an even-numbered 12-by-12 deck will not require this.
What is a Joist Tape?
Joist tape is a self-adhesive tape composed of rubberized asphalt that is applied to the ends of cut joists to help protect them from water and prevent sound transmission. It is available in a variety of colours and sizes.
DPC on Decking Joists- Does it work?
The wetness in the structure generates unsanitary conditions and also decreases the structural strength of the building’s structural components. In order to keep moisture from creeping up the walls, it is necessary to install a damp-proof course.
A DPC, or Damp-Proof Course, is a horizontal barrier installed in a wall to prevent moisture from rising through it from the foundation. A DPC layer is usually laid below all masonry walls irrespective of whether the wall is a load bearing wall or a partition wall.
The surface on which the DPC is laid shall be thoroughly cleaned and wetted before starting the work. When it is raining, the DPC should be set at a level that water sprays from the ground into the air. In order for the DPC to be effective, it must be installed at a level at least 15 cm above the highest ground level.
Always install a damp-proof course between the source of the moisture and the portion of the building that is near to it. Damp proof course should cover the full width of the deck (if applied to deck joists).