Garden Decking Designs – Split Level Decking
Split Level Decking
This is a simple deck, combining two decks that overlap each other to create a split level.
The different directions of the deck boards on each level show the height difference. The garden was very wet and shady which meant it was out of bounds for most of the year, but the addition of the deck has allowed more use and less maintenance.
The aspect of the garden means it has shade problems and as such is a poor spot to grow even a basic lawn. The first plan was to have a small deck outside the patio doors and a second larger one under the window extending out into the garden.
When at the planning stage it was noticed that the second deck would have been fixed above the damp coarse, this was deemed unacceptable as it could encourage damp into the walls. In the final design a longer low deck was positioned up against the house below the damp coarse, which alleviated the gap that would have been left between the house and the main deck and a step up to a second deck in the garden.
The second deck was to be used for barbecues, so a large low level was incorporated that covered part of the old concrete slab patio and part of the wet garden. In the construction, the posts were placed on a concrete block that kept the timber above ground level and out of the wet soil, thereby reducing the chance of decay. It was important to treat all cut surfaces with preservative to stop water entering in these condition’s. As the deck is in a shaded damp position, the surface will need treating regularly to prevent algae from growing on it.
1. Measure and cut the timber for the first square. If you have a flat area of ground you can make up the first square of the deck frame, then move it into position and bolt it to the wall.
2. With the outer frame completed on the first part of the deck, cover the ground with weed block and complete the first base as before, screwing the joists together at 40cm centres. Take care of the ones near the air brick where the gap is narrower to avoid obstructing it. The second part of the deck can be put together, the outer frame first, and then the two sections screwed together before fixing the other joists, as it will be difficult to get the drill in between them. Any areas of grass need to be covered with more weed block. Then fix the joists in position as before at 40cm centres.
3. To prevent the air bricks from being obstructed, cut away any timber that will cover-them and add a second length of joist inside to carry the deck board.
4. If the deck is going to be above ground level, add posts. Dig a hole and stand the posts on a concrete block to spread the weight. Secure using.
5. If the joists are over 1.5m in length addto stop them spreading when the deck boards expand in the wet. If the noggins are not visible you can nail them.
6. Diagonal boards need to be laid with the use of a square to obtain the correct angle. Using spacers as before, leave a 5mm gap between the wall and the end of the deck board, and 5mm between the boards. Leave extra space when you get to the air brick. Use the square and spacers to place in the correct position.
7. After the deck boards have been laid, finish the edging detail by sawing off the excess timber with a circular saw. For any difficult areas use a sharp hand saw. Paint the ends with preservative.
8. To ease the transition from the lower to upper deck, a cut-off corner is created using a section of timber cut at 45° angles each end and fixed across the corner to each joist. Proceed toon the rest of the top frame.
9. Where the frame is above a solid concrete base,a hole into the post, then knock in, bolt and tighten coach bolts. Remember to seal any cut ends with timber preservative before fixing together
10. Remove the manhole cover, trim the weed block around it, then replace the cover. Fix the first timber across the width.
11. Fix joists far enough apart to able the access to the manhole cover
12. As you work across the deck cut short boards around the manhole cover and then continue each board to overhang as before. Space the noggins through the centre of the deck to increase the ridgidity of the base. Posts can be fixed to both joists to give a more secure joint.
13. Using a straight edge as a guide, run the circular saw along to trim off the overhanging deck board and so complete the split-level deck.