Technique #1 - Hide the footings and the posts. Deck support posts can sometimes end up being a little bit off-center on top of the footings for one reason or another. In any case an inch or two will not affect the strength of the deck foundation.
However, anyone looking at the post and footing from the side might not be too appreciative of their appearance. People will not be able to see the imperfect footings if the joists are cantilevered 24 inches or more beyond the support beam.
Hiding the footings well under the deck is also a great method for hiding the beam so if the deck and the beam aren't perfectly aligned, it will not show. The large beam pieces, usually an unattractive pair of pressure treated two-by boards, are often ugly to look at, so hiding the beam under the deck actually will make the deck look better.
This is especially true and important when high end materials are used in the deck design such as redwood or cedar for the decking.
Technique #2 - Let the lumber run wild. Although all of the parts of the deck will eventually be trimmed neatly to exact lengths, try to wait until the last minute in order to make the cuts. Leave the posts, joists and decking too long when they are first installed. Then cut them later to the correct size.
This method is called letting the lumber run wild and it can certainly be an important construction technique for building a great looking deck. Professionals have utilized this trick for many years.
For example, if the wall of the house bows out and all of the joists are cut initially to exactly the same length, then the bowed out wall will simply be duplicated. Instead let the joists run wild. Snap a chalk line across the tops and cut them all off in perfect alignment.
Technique #3 - Attach built-up beams to the posts. When beams are placed on top of several posts it is a necessity to trim all of the posts to exactly the same height prior to installing the beams. This can be a very challenging task, especially when a long beam span might be required to connect 5, 6 or more posts.
A simpler method is to let the posts run wild upward. Create a beam composed of 2 or more pieces of two-by lumber that are attached to the sides of the vertical posts with lag screws or carriage bolts, washers and nuts.
Using this design technique it is possible to check and recheck the beam for level before installing and tightening the lag screws or carriage bolts and correcting any mistakes as the work progresses. Then it is simply a matter of cutting the posts flush to the top of the beam only after the beam is in place and fastened securely. Any construction plans should show this method clearly to avoid confusion when framing the deck.
Technique #4 - Use overhangs and underhangs. In situations where 1 piece of lumber supports another it seems most practical to trim the upper piece flush with the bottom piece in order to create a smooth, uniform corner. However, a gap may open up after a period of time especially in situations where deck lumber might be prone to expansion and contraction.
In many cases, a planned overhang or underhang can look better than a flush cut. It is usually a good idea to let decking overhang the joists by an inch or two. Railing pieces can also look best overhung as well. A rail overhanging a post is a benficial way to prevent water from collecting in the end grain of the 4x4 or 6x6 post.
Although it is not done very often, letting the beam extend well beyond the end joists can be especially attractive and add much to the finished look and style of the deck. Consider carving the ends of the deck beams or even cutting them on an angle to add a bit of artistic detail and flair.
Technque #5 - Install added-on railings. It is quite possible to design a deck so that the posts supporting the beam extend up through the decking and eventually become the main supports for the railing system. This sounds like a good idea, however, a longer post is much more difficult to install perfectly plumb. If the railing posts are not plumb or not exactly aligned, then it is almost a certainty that the railing will look less than attractive.
A much more forgiving technique is to construct the deck first. Once that has been completed, the railing support posts can be bolted to the outer joists or fascia. Once that has been accomplished, the rails and balusters can be installed in place and fastened. This type of added-on railing system can easily be just as sturdy as one using the continuous post construction method.
Technique #6 - Build the stairway after the deck. Stairway design can be a complicated issue. It can take a fair amount of measuring and figuring to find out just where the stairway will end. So it is more practical to wait until the basic deck is complete before the position of the stairway posts and the landing slab are worked out.
The posts that support the stair railings quite often require extra lateral support. Instead of doing the traditional post-on-footing arrangement, stair posts can be extended down inside the footing forms with concrete poured around them for extra strenth.
In building a stairway use screws in place of nails. If it is necessary to reposition a baluster or pull up a stair tread, it will be far easier to remove the screws fastening it. In all likelihood, the baluster or tread board will not be damaged and can easily be reused.
A successful deck design is the product of extensive research, careful planning, a bit of imagination and careful attention to proven construction techniques and will result in an outdoor deck space that will service the needs and lifestyle of family members and guests for years to come.