How to build a raised timber deck
111 views Sep 16, 2017
How to build a raised timber deck

It is easier than it looks to build a raised timber deck.  Timber decks can be designed to meet most design situations. According to the Timber Decking and Cladding Association Desired service life options of 15, 30 and 60 years are given in European/British standards.

It should be noted that 15 years is considered to be the minimum standard.  For new the NHBC insists on a 60 year service life in accordance with TDCA Code of Practice TDA/RD 08/01.

Building a simple timber deck is straightforward and is considered less expensive and more environmentally acceptable than bricks or flagstones.

The following step-by-step guide covers and is consistent with most of the basic applications to install timber decking and while these instructions are for guidance only please always remember to check with supplier specifications.

Step 1:

Make sure you plan in advance to ensure that boards will be flush with your frame. Prepare a level area for the framework by cutting the timber to the required length, then join using exterior wood screws. Check the frame is square by measuring from corner to corner and adjust if necessary

Step 2:

If you need to raise the frame, cut four blocks of timber to the desired height. Screw these to the inside of the frame at each corner, ensuring they're flush with the top. As these legs will be taking all the weight ensure you use at least three screws per block,

Step 3:

Place blocks or slabs underneath edge leg to spread the load and provide a level, stable base if your deck is sitting on grass or soil. Position and adjust checking the frame is level using a spirit level

Step 4:

Three joists are sufficient (one in the middle and the others at the centre-point between the edge of the frame and the centre joist) if you are building a small deck. Mark across one side of the frame first, then repeat on the opposite side. On larger decks, set joists at 400mm centres

Step 5:

Ensure that you measure across the inside of the frame at the joist marks before cutting lengths of the timber to suit. Fix the joists by tapping them with a rubber based mallet until flush with the top, then screw them in place from the outside of the frame

Step 6:

Support the joists with additional legs, spaced at 1m intervals. Follow the same method as shown in steps 2 and 3 for these legs, ensuring each is supported by a suitable block or slab

Step 7:

For the facing, measure the length of the outer sides of your frame and cut the decking boards to suit. Mark the cutting lines with a square to ensure a straight edge. Countersink the facing and screw to the frame, ensuring the facing is flush with the top

Step 8:

Now you are ready to start laying the deck. Measure across the top of the frame and cut a board to length. Place the first board flush with the outside edge of the frame and facing, and perpendicular to the joists. Mark the location of each joist on the board

Step 9:

Mark and countersink screw holes over the centre of each joist. Be sure to use a sharp countersink that will leave a clean hole. If necessary, drill a pilot hole to prevent splitting. Use at least two screws per joist for each decking board

Step 10:

Ensure you have a 5mm expansion gap between each board (as timber expands and contracts according to outdoor temperatures). Use a spacer to do this.

Step 11:

Continue the process until you have completed the job.