Building a Deck

Building a deck is challenging task. There is often a good amount of digging. Cement must be mixed and hauled. Heavy treated lumber need to be moved into the deck area. Anything that can be achieved to limit problems as well as complications will make the job move smoother.

Building A Deck

Making a deck involves a number of components. Grade beams, digging, post holes, joist hangers, ledger mounting bolts, nails, stairs, landings, deck plans and design. There are many things to take into account.

Deck Plans

Be sure your deck plan is well done. Put together scale cutouts of the deck furniture, bbq, patio table, etc. Be sure that the cutouts fit on your plan and people still have room to move around. Almost nothing could be worse than constructing a deck that is too small. Look at your neighbour's decks. See how the table works in the middle? Learn how much room you'll need for chairs sliding in and out? If this doesn't work on paper, it'll never work in reality.

Deck Layout

Here is the easy technique of doing a layout. Build the outer structure only and suspend it in the air utilizing temporary legs. This allows you to square up the frame correctly. Aided by the ledger board safely and securely secured to the house, both the joists as well as the outer band board can move laterally. Squaring the frame is easy. As soon as the two diagonals measure the same distance, the frame is square. Now you may mark your post centers. This allows you to position your piers correctly.

 
Digging Post Holes along with Grade Beams

By using a post hole digger that has sharpened cutting edges allows for easy digging. Post or pier holes need to be bigger at the bottom in comparison to the top. Most DIYrs do just the exact opposite. Frost can heave a tapered pier right out of the ground. When piers are larger at the bottom, the pier has to "lift" the nearby frozen soil. That is difficult to do. Utilize a round point spade for general purpose digging.

Ledger Boards Need Through Bolts

The board that is attached to your house is called a ledger board. It needs to be through-bolted to your house. Lag bolts can pull out over time and weaken the deck. Be sure to stagger the holes for the ledger board and make sure they are not in the way of your deck joists. You need to locate your interior joist bays if the house joists are running in the same direction as the deck joists. Ideally, you want your deck joists to be in the same line as the interior joists - assuming the interior joists are 16 inches on center. The point is simple - you want to make sure the through bolts do not get in the way of a deck joist or a joist hanger. The time spent laying this out will pay for itself. Be patient with this process!

Joist Hangers Need the Right Nails

Did you know that you can't use roofing nails for joist hangers? Many DIYrs do. Roofing nails are not "structural" nails. The heads pop off easily when loaded and the shafts are too thin. Many joist hanger manufacturers make special hot dipped structural joist hanger nails. They are a must. There is nothing worse than removing nails after the building inspector turns you down.

Pay Attention To Your Posts!

How are you going to support the beam on the posts out at the end of the deck? Are you going to nail them to the posts? Don't! Drill holes and install through bolts? That is better. The best way is to use 6x6 posts. You can then cut a ledge into the 6x6 for the beam to rest upon. The remaining portion of the 6x6 still extends to the top of the beam. This allows you to through-bolt the beam to the post. You can set the beam on top of the post as long as you use special structural connectors made for this purpose.

Flashing the Ledger Board at the House

If your house has wood siding it might be a very good idea to install a flashing that laps over the ledger board and extends up behind the siding. This prevents water from getting behind the ledger board. This water can leak through the bolt holes and rot the siding and structural framing of the house. When you nail your final decking board up against the house, do not nail through the flashing! Just nail into the deck joists that project out from the ledger board. If you end up with a small strip, then install the strip as your second last decking board using a full sized piece against the house.

Seal the Lumber Before Construction

If you are building a deck that is close to the ground - the bottom of the joists are 18 inches or less from the soil - then you should really seal the floor decking boards on all sides before they are installed. This will slow or minimize water vapor absorption on the underside of the lumber over time. This absorption coupled with the drying effect of the sun and wind on the top side of the deck is the leading cause of cupping. Decking that is cupped is simply unsightly. It also traps water and ice on the decking boards. This is dangerous and leads to accelerated deterioration.

Keep the Outer Band Board Straight!

Once you start to install floor joists in your frame, it is easy to bow the band board. You can keep it straight with a string. The trick is to stretch a string tightly on the outside of the band board from corner to corner. Now install a small 1/2 or 3/4 inch block of wood under the string at each corner. As long as you maintain the outer surface of the band board the same distance from the string as you add joists, it will remain straight. I always like to install the middle joist first to get the center of the band board perfectly in line with the corners. I then split the newly created half sections with a joist. Once you do this, you can fill in the remainder however you like.

Avoid Electroplated Galvanized Decking Nails

I used to think my shiny galvanized decking nails were the best. Wrong! They usually begin to rust within two years. Use either stainless steel nails or decking screws. At the very least, use hot dipped galvanized decking nails. Be sure you drill the nail holes at the ends of decking boards. Nailing that close without pilot holes will crack the decking.

To Space or Not to Space Decking

If you are using pressure treated lumber for your decking, do not space it. A 3.5 inch wide piece of decking can shrink as much as 1/8 inch - sometimes 3/16 inch! Redwood is more dimensionally stable. You can space it with a 16 penny nail or lath strips. Some cedar decking will shrink. Ask your lumber supplier if the cedar is kiln or air dried. Air dried cedar will shrink. Don't space air dried cedar!

Railing Posts - How to Attach

Railing posts must be very secure. They absolutely must be bolted in two locations along side deck joists. Sometimes deck posts can extend continuously above the beam to become a railing post. I will often cut down the 6x6 post to a 4x4 above the beam for this specific purpose.

Stairways To and From Decks

Stair building is an art. It requires lots of thought and layout. A beautiful deck can be blemished by a poorly constructed stair or one that is not balanced. I feel the most comfortable steps are those with 10 inch treads and 7.5 inch risers. This means that you need to plan your landings and deck heights. Multi-level decks must be built at some multiple of 7.5 inches from one another.

Landing areas from driveways or sidewalks need to be this same multiple if at all possible from the finished surface of the decking. Don't make the mistake of measuring straight down from the deck for your stairs! You need to measure from where the stairs will end out from the deck. Get an approximate height measurement and figure out how many treads you will have. Multiply this by 10 inches. Measure out your calculated distance and then see the difference from this point to the top of the deck.

More Info On Deck Building:

Deck Design