DIY Decking Boards

How to Lay Decking Boards

After deck framing is complete, it is time to lay the decking.  There are all types of decking today to meet your needs.   Finding the best decking for your application will depend on a lot on your needs. 

Do you want maintenance free decking? Use a composition material? 

Do you want a traditional look? Use standard pressure treated decking. 

For a most exotic decking material, there is cedar and mahogany just to name a few that are rot resistant, durable, and attractive to look at with finished.  Then, there are different installation methods, nails, screws and new ‘hidden fastener' systems now available to pick from.

Traditional decking is run perpendicular to the framing to give a solid nailing foundation.  In this case we will talk about running the decking at a forty-five degree angle to the framing.  Running the deck this way will take a bit more time and material, but in the long run, it will give you that professional look to enjoy.

The first few decking pieces are the most important because everything will follow this starting point.  Using a speed squares forty-five degree side, mark the framing for the first piece, which will look like a small triangle.  Be sure to leave 3-5cm over hang on the outside edge to overhang the deck framing. 

Using stainless steel nails will serve two purposes, first, they will not rust, and second, they will give the deck another touch of class showing real style. 

Now, if there is not flashing on the framing against the house, you need to get it and install it before decking can be applied.  You should use framing that is 15 - 20 cm wide to be able to run a good 10 cm up on the house and the bend the rest and lay on top of the framing.  This is to help channel water away from the house and cause water damage or rot. 

With the flashing installed, it's time to check and re-check the fit and that it is sitting at forty-five degrees with the proper over hang.  If all is correct, it is time to nail the first piece.  Pre-drilling may be required if this piece is small so you will not split it.  After this piece is nailed in place, re-check that it is forty-five degrees to the framing as it is easier to remove one piece than half a deck's worth if it is not correct.  With the first piece installed, measure and cut the second piece, again leaving the same overhang. 

When nailing, use two nails per deck joist and keep the nails running as straight as possible on the joist so when the decking is complete use end up seeing nice straight lines of nail heads. Laying the rest of the decking, you need to make sure there is a space, uniform and even between each piece of decking.  This can be done by simply using your decking nails and hold the nail against the piece of decking already installed and gently nail into the deck framing to use as a spacer.  Only tap the nail into the framing to be removed and reused. 

Putting a nail in every (or every other) deck joist will give you a nice uniform space for a finished looked.  Also, at this point, if you have any boards that are not totally straight, you can bang a flat head screw driver into a joist and wedge the board into place.  If this is needed it would be a good tip to start a nail in the deck so when the board is wedged into position all you have to do is set the nail as one hand will be already prying the board up tight to the nail spacers already. 

If a board is really bad, sometime if you cut it in place to use part as a starter piece and the other part as a seam later piece will help eliminate the issue and you will not have to scrap the entire  piece.  When bending a warped piece, take it slow and careful and work the piece from one end to the other to work the piece into place. After you have the first 3 - 4 deck boards installed, you can now let the outside edge run long to cut later.  Now that the decking is started, you will need to carefully plan out any seams required.  All seams must fall on top of the deck framing joist.  Be careful when measuring because the seams need to be cut on a forty-five degree angle to make sure then entire end or the decking is supported by the framing.  Also note, that each piece of decking making up the seam can only cover one half of the joist. 

When nailing the seams, you need to ‘toe nail' the ends by angling the nail to make sure it is solid into the joist.  The best looking results for this would be to pre-drill the ends at a thirty degree or so angle to make sure the nail is solid into the framing structure.  These seams should not have any gap in them like the decking does between each board.   When measuring to make seams, make sure there are not seam right next to each other.  All seams should be at least 3 to 4 deck joists ways and as random as possible.  Making the seams random will cause them to blend into the entire deck and not creating an eye sore. Continue the decking in this fashion until you can over hang both ends of the decking.  Make sure the first 3 -4 deck boards up against the house are cut to the proper length/over hang as this will be clear when the entire decking is completed.  

If the railing posts are already installed, carefully measure and notch the decking so you have a nice tight seam around the base of the post.  The only gaps in the decking  should be between the decking material itself and not around posts, other obstacles, or the deck seams.  Continue decking the entire field, making tight seams, proper spacing the decking boards and leaving enough overhang around the edge of the deck to be cleaned up when the entire deck is covered. 

After the decking is all installed, go back and make sure all the nail heads are flush or even a little ‘dimpled' in the decking so no one in bare feet will get hurt.

Now, remember all the boards overhanging the edge of the deck in various lengths, well it is time to clean them up. 

Carefully measuring the proper overhang on one side of the deck, mark the two boards at each end of the side and snap a chalk line between them.  Using a circular saw, cut on the chalk line but you will notice that if the first 3 boards were not cut to length, the saw would not be able to cut them as the saw guide would hit the house first.  Cutting the boards this way will give you a nice even line and not a bunch of edges at various lengths not matter how hard you try to make then even.  Using this method, even if you drift a bit off the line, it will still be a nice smooth, even, line to look at.

When cutting the boards, take care in cutting the last board so it does not care or splinter.  Having someone hold the board up will help the board not fall and crack itself. After you finish trimming the first side, use the same method to trim off the excess length on the opposite side, again carefully measure the last two boards to be cut and again, snapping a chalk line to use as a guide to cut the boards to length.  With the sides trimmed to length, repeat the process on the end, carefully measuring the same over hang as the two side and cutting a nice straight line. 

If you do not run the decking at the forty-five degrees as explained here, you may find that the last board to install is not a full board and depending on the decking width, it may need to be split in half, or in some cases even more, leaving a very small piece as the last piece.  Running the boards at the forty-five degree angle eliminates this issue, and while it does have more waste and take more time, it gives the deck a very professional look to it when done properly.

When all sides are now trimmed, you should think of sealing the deck to help it last for many years to come.