Dangerous deck (C) Daniel FriedmanDeck Framing for Complex Designs
Deck Design-Build Online Guide

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How to build a multi-level or non-square deck. This article describes cutting angles, non-square corners, and also special framing to support a hot tub or spa to be located on or built into the deck.

This article series describes details for decks and porches, including avoiding deck or porch designs that include multi-level decks, complex deck layouts building a deck over uneven ground.

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Deck Framing Techniques for Complex Deck Designs

Pier installation details (C) Daniel Friedman

Single-level rectangular decks are the easiest and quickest to build.

But it does not necessarily take much extra effort to add some variety to this basic design. And some decks almost demand to be built with multiple levels, around a corner, or without damaging the health of a favorite tree.

The simple angles on this little entry deck under construction in northern Minnesota afforded a more interesting design. The deck is large enough to allow visitors to sit with a view of the nearby lake (just seen through the trees) and to serve as an entrance to the green cabin.

Cutting Angled Deck Corners Adds Interest

Angled corners are an easy way to avoid a boxy-looking deck. Although you can use any number of angles, it is smart to stick with 45-degree angles.  Build the deck as though it were a normal rectangle, then cut the framing to allow for the angle. A short 45-degree corner requires only two cuts in the framing.

Set your circular saw at a 22 1/2 degree angle and cut the rim and end joists as close to plumb as you can. Cut a short filler piece with a 22 1/2 degree angle on each end and attach it with nails.

A larger angled corner requires cutting several joists. You can increase the size of the corner by maximizing the distance that the joists overhang the beam (check your building code for restrictions).  Snap a chalk line across the tops of the joists to guide your cutting.  For a long angled corner, you would need to install an angled beam to provide the necessary support.

Turning Corners in Complex Deck Designs - wrap the deck around the building

Wrapping a deck around the corner of a house offers many benefits, usually with minimal added effort. It can allow you to take advantage of different views or micro-climates, create a private area, or make it possible to reach a deck from more than one door to the house.

One of the first decisions you need to make with a wraparound deck is how you want to install the decking. There are two styles that can be built and both can be framed the same way. Both have decking that runs entirely in the same direction, one across the joists and the other at a diagonal. Both have three parallel beams, although the diagonal design includes a short diagonal beam that allows for an optional angled corner.

Perhaps the simplest deck to build is essentially two conventionally framed rectangular decks that meet at the comer of the house, but with one ledger extended under the decking. The mitered decking pattern requires more time and effort, but produces what many will find to be a more attractive deck.

Level Changes in an Exterior Deck

Level changes can dramatically boost the visual appeal of a deck. While separate decks, built at separate levels, can be constructed next to each other, the most efficient and cost-effective approach is to use the same foundation to support adjacent levels. The transition between levels, no matter how wide it is, constitutes a step and should be designed to provide a safe and code-approved rise

Shared Beams in Multi-Level Deck Designs

Multi-Level deck, Poughkeepsie NY (C) Daniel FriedmanA relatively easy technique utilizes one beam to support two levels. The rim joist for the upper level falls directly over the lower rim joist, and the two are joined with tie plates.

This style of level change can also be built by attaching the lower joists to the side of the beam with joist hangers and securing the upper joists to the top of the beam. With 2 X 6 or 2 X 8 joists, the shared-beam technique creates a comfortable step between levels.

Shared Posts in Multi-Level Deck Designs

A technique using shared posts is preferred if you want to create a greater difference in height between two levels, which must then be joined with stairs.

Plan to use 6x6 posts, which must be notched on two sides to accept the lower beam. The upper beam rests on top of the posts, with joists overlapping or hung from the side of the beam.

Stacked Deck Designs Give Small Raised Areas

One way to create a small raised area is simply to construct a separate deck frame and set it on top of the regular frame. Use tie plates to hold the top frame in place, and attach short joist sections to the joists on both sides of the upper level to provide nailing surfaces for the decking.

Although it is not particularly cost-effective for large sections of the deck, this technique is a handy way to create a step up to the house.

Simple Openings in a Deck Floor

Deck notched around tree (C) Daniel FriedmanSometimes it is necessary to build a deck around a large object, such as a tree.

Small openings can be framed quite easily. First, install double joists on both sides of the object. Then attach header joists, using two pieces of joist stock, between the joists on the other two sides of the opening.

Outside the opening, attach joist sections to each header, maintaining your regular on-center spacing. Cut and install the decking so that it overhangs the framing by about 1 inch on all four sides. Use joist hangers (3 inches wide for double joists and 1 1/2 inches wide for single joists) at all connections.

If you would rather create a round opening to better match a tree trunk, start by framing the opening.

Then cut and install four diagonal joist sections. Install the decking so that it covers as much of the opening as possible, then mark and cut the circle.

If you are building around a young tree, take extra care to allow plenty of room for the trunk to expand.

Access Panels in Decks

Deck floor access opening (C) Daniel FriedmanIf your deck will cover a water faucet or electrical outlet, you may need to build a small access panel. Attach 2x4 cleats to facing joists, 3 1/2 inches from the top of each joist.

Build a frame with 2 X 4s, with the frame width about 1/2 inch less than the distance between joists. Cut and attach decking, then drill two finger holes.

Framing Around a Deck Hot Tub

While a standard deck should be able to support the weight of a small children’s wading pool, a larger hot tub or spa requires added support. This support is generally provided in one of two ways, as described below.

Choose your tub or spa before you begin building, and be sure to follow the manufacturer’s instructions. Keep in mind that you will need to have some plumbing and electrical work done, and you may want to give some extra thought to privacy and shading when you design the deck.

Framing around A Deck Spa or Hot Tub

On a low deck, it is usually best to rest the hot tub or spa on a concrete pad.

Check with the manufacturer and with your local building department for specifications on the size of pad required, and plan to pour the concrete before you begin framing the deck. When a spa or a tub is installed with this approach, the deck frame surrounds the tub or spa, but provides no additional support.

The top of the tub or spa can be above the surface of the deck, or be level with it. If you prefer the latter style, plan the height of the deck very carefully. The framing is similar to that needed around a tree, except that a larger opening is needed.

Supporting Deck Framing Beneath The Hot Tub

If you prefer to set the hot tub or spa on top of the deck surface, you will need to substantially increase the framing beneath it. The frame must be able to support the weight of the tub or spa filled with water and people. Check with the manufacturer or a structural engineer for more detailed recommendations.

Once the decking has been installed, you can construct an elevated platform to surround the tub or spa; make sure to allow for that weight, too, in your planning.


Continue reading at DECK PLAN & SKETCH or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see DECK LEDGER BOARD INSTALL if you don't give a darn abouit good deck constructin planning & want to just get to work framing.

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