How to design a deck

All you need to make accurate deck plans are a pencil, ruler, and graph paper.

Draw your deck to scale on graph paper (typically 1/4″ to the foot). You’ll need at least a site plan, a plan view, and one or two elevations. You also may want to draw detailed plans for complex parts of the deck. Drawing plans can be tedious, but it’s worth the effort to make the project go smoothly.

Take measurements

Deck plans begin with measurements of your property. Take a 100′ tape (and a pad and pencil) out to your yard and measure the distance from the house to the property lines, as well as the dimensions of the house, the location of windows and doors, electrical outlets, dryer vents, and water valves.

Draw a site plan

A site plan is a drawing that shows your property boundaries, the house, and other major features. It also shows the distances between elements in your landscape that might affect the deck construction. A simple deck plan only needs to be a sketch that includes these measurements. More complicated deck plans will require a scaled drawing.

Make detailed plans

With detailed plans that show every framing member, you can count the pieces of lumber you need. You also can show obstacles such as dryer vents; plans will help you work around them. Detailed plans can also save you money. For example, because lumber is sold in even lengths, you can keep costs down by making deck dimensions correspond to those lengths. If your detailed plan specifies a 12 1/2′ ledger and you can reduce the size to 12′, you’ll avoid cutting a 14′ board and wasting a lot of lumber.

Complete a plan (overhead) view

A plan view shows the deck as viewed from above. It illustrates the exact location of piers, beams, and joists. It also may include a partial view of the decking, railing, and any other structures attached to the deck. The drawing shown combines a view of the framing with the decking installed above the beams and posts. For more complex decks, these two views can be drawn separately. Draw the foundation and framing plan first, then use tracing paper to produce the finished view.

Include all dimensions overall length and width, joist and beam spacing, and material sizes.

Elements of an elevation (side or front) view

A front or side elevation illustrates the vertical arrangement of deck elements footings, posts, railings, and any built-in planters, benches, or overhead structures. Each elevation should show the depth of the footings and spans, plus post and railing dimensions. Railing dimensions should indicate the height of the railing as well as baluster spacing.

Tip: computer-assisted planning
Design your deck with computer-assisted drafting (CAD) software. Most CAD versions will produce a plan view, an elevation, and a perspective. Many also will produce a list of lumber and other materials.

If you’re not confident of your computer skills, ask your home center staff for help. Many retail outlets offer computer planning programs and have staff members who know how to use them. Bring in a rough drawing with dimensions (height, width, and length) and have the computer draw your plans.

Written by Chris Nolan on Tue, Feb 5, 2019 @ 05:02 AM

People with flat roofs love rooftop decks, and why not? Often it’s an otherwise wasted space. A rooftop deck can provide a whole new perspective for you. You can have a commanding view of your whole area. What a great viewpoint. Before you get started, though, there are many important things to consider. It’s best to do your homework first.

How to design a deck

First Step: Is a Rooftop Deck Allowed in Your Area?

Before getting started, find out if a rooftop deck is allowed in your area. Do you have local zoning prohibiting a rooftop deck? Are there homeowner association restrictions in your area? Find out. If not, a great place to start is to check with your local building department. Building code officials are a wealth of information. They know the local building codes and can save you money in the long run.

Step 2: Can I Build a Deck on My Rooftop?

Can your roof structure support the additional weight? A building code official may be able to help you here. Or not. At a minimum, they will likely know what the loading requirements are in your area. You may also need a master builder or structural engineer to determine the loading capacity of your roof. They can determine whether your existing roof can support the extra weight of a deck. Never build a rooftop deck without checking this first.

How to design a deck

There is plenty more design inspiration and information where this came from. Grab your FREE download of the “Rooftop Deck Design Ideas Project Portfolio” and start designing your dream rooftop deck.

Step 3: Choose your Deck Team Wisely

Architects, landscape architects, engineers, green roof professionals, master builders all have their specialties. You may want to interview several of them before deciding on your rooftop deck team. Green roof professionals often have many (or all) these resources in house. If not, they will likely consult with an architect or engineer first anyway. Ask them about their process. Find out how experienced they are. It’s well worth it.

Step 4: Plan Your Rooftop Deck Design

You may already have some ideas on how to utilize your rooftop deck space. Are you going to have plantings? An overhead element like a pergola? Seating areas? Do you need access to drains or utilities? Professional designers can help you plan wisely for your unique space. Enlisting experienced professionals can save you years of grief and add many years of enjoyment. Your call.

Need some rooftop deck design inspiration?

Download the “Rooftop Deck Design Ideas Portfolio” now.

Step 5: Select Your Rooftop Deck Framing

The basic options are sleepers, wood framing or adjustable pedestal systems.

  • Sleepers. Sleepers are less costly up-front, but they have pros and cons. Check out this article on installing sleepers for a better understanding.
  • Wood Framing. Traditional wood deck framing is an option, too. The benefits are also a low-cost option, up front. The downside is they may potentially be too heavy for your roof to support the extra weight. Because a low-clearance rooftop deck is a harsh environment, wood joists may warp, twist or rot.
  • Aluminum Joists. A high-performance adjustable pedestal system with aluminum joists is more expensive up front. However, they will not rot, warp or twist and they are non-combustible.

How to design a deck

Step 6: Select the Right Decking for your Rooftop Deck

Rooftop decks are possibly the most punishing area to build a deck. They’re low clearance (moisture can get trapped below), low ventilation and high exposure. They often see the sun all day long. Choosing the right decking to survive – and thrive – in this environment is an important decision.

No more guesswork. Download this FREE “Ultimate Guide to Selecting The Right Decking” now and get the first steps to finding the right material for your project.

How to design a deck

What about Composite decking material?

Synthetic decking options range from wood composites, to plastic capped wood composites, to cellular PVC. Most are available in a variety of colors. Some may perform well in this harsh area. Most do not. Most of the synthetics heat up and expand and contract making them uncomfortable to walk on. If you are considering this option, please do your homework first.

How About Softwood Decking Material?

Softwood decking is not a very good idea on a rooftop deck. Pressure treated decking is very likely to split, crack, warp and twist in this harsh environment. Even higher-quality softwood decking, like cedar, will require a lot of refinishing up at this height and exposure. If it’s not refinished regularly, expect lots of splitting and checking.

How to design a deck

How About Hardwood Decking Material?

High density hardwood decking species such as Ipe, Garapa and Machiche, and Cumaru hardwoods are an excellent consideration in this environment. There are many high-performance hardwood decking species to choose from. They will work as well as the deck layout allows. For example, the more clearance you have below the deck (height from top of roof to bottom of deck boards), the better. The spacing between the deck boards is also critical. This is very likely the only place your deck will ventilate.

Looking for the right decking material for your rooftop deck project?

Download the “Ultimate Guide to Selecting the Right Decking”

How to design a deck

Decking Size Matters:

  • Thicker deck boards perform better than thinner ones. Thicker boards are stronger and can take more punishment. (Either ‘5/4 x’ nominal thickness or 21 mm thick decking are better than ‘1 x’ nominal thickness decking)
  • Narrower deck boards will perform significantly better than wider boards. For example, a 4” nominal deck board will ventilate roughly 40% better than 6” nominal decking. This is because there is a lot more ventilation between the deck boards. Trapped moisture can escape more easily.
  • Thicker, narrower deck boards work best of all.

Ready for pricing for your rooftop deck? Request a rooftop decking quote today.