Here is an easy DIY terrace construction Plan.
A full description is given of the materials you will need, the full design details and the installation instructions.
You will be able to fix that difficult corner, or use this idea to build that needed flower box.
This terrace construction idea makes use of timber. It is very neat and will fit in well with timber garden walls.
You may also paint it to complement the architecture of your home.
Sawn treated fence posts (75 x 75mm x 2.4m, or 3 x 3 inch x 2.7 yard)
Sawn treated planks (25 x 150mm x 2.4m, or 1 x 6 inch x 2.7 yard)
Colonial hand rail (31 x 83 x 2.4m)
Wood screws, countersunk, zinc plated (5M x 60mm or 2.5 inch)
Builder’s plastic sheeting
Stones and pebbles
The Terrace Construction Design
Fence posts will be planted 1.2 meters apart (centre to center). Plant depth should be at least 450mm.
The planks will be screwed onto these posts. The inside of the terrace will have a drainage furrow.
This is used to drain off excess water. A builder’s plastic is placed against the inside of the timber,
this should keep moisture away from the timber. This helps to prevent the wood from rotting. Our basic design is shown below.
A Section of Terrace Construction Design
Getting the Materials Quantity Right
First determine how much material you need all together. Measure the length of your required terrace.
Divide the length by 2.4 meters. This should give you the number of plank sections to be used.
Decide on how high you want the terrace to be. I suggest you keep it to a maximum of around 60 cm (600mm).
Each plank is approximately 150 mm wide. This means that you can select your terrace in multiples
e.g. say 300mm, 450mm, or 600mm high. Depending on how many planks you decide to place on top of one another.
The total number of planks will be the number of plank sections times the number of planks required for your height.
For example a 4.8 meter long terrace 600mm high will require 8 planks (2 for length x 4 for height = 8) ,just do the maths.
Adjoining planks should be screwed onto the same post.
The posts can be planted 1.2 meters apart (i.e. one at each end and one in the middle of each plank).
For our example shown above, you will need 5 posts (one at the start and then two for each planks length).
The length chosen for each post will be 1,05 meters (600 mm plus 450 for planting).
If you have a curve in the terrace construction, you will have to saw the planks to approximate the curve.
See the sketch below. You will also require longer screws to secure some of the planks.
Terrace Construction - Curve Approximation
Make provision for drainage at the lowest point of the terrace construction.
Here is a sketch for your terrace drainage design
. Note that the bottom plank should be 220mm shorter for your hole.
Let the timber supplier cut your timber to all the correct lengths.
Just ensure you have planned it properly before you start cutting it!
Installation of the Terrace
Measure out the exact position for each post. Dig the furrow that will be used for drainage between all the post positions.
Dig a hole for each of your posts to the correct depth.
Put a post into each hole. Make sure that all your holes are at the correct depth.
You can accomplish this by holding two adjacent posts upright, placing a straight plank over the top of both,
and checking that they are level using a spirit level. Adjust the depth of each hole until everything is level.
Choose a side of the terrace to start from. Position the top plank first flush with the edge and top of your post.
Drill a pilot hole and screw in only one screw at this stage. Next fix it to the post situated at the other end of the plank.
Align the plank level with the top of that post, but only to the middle of that post to allow the next plank to be joined with it.
See below. Again use only the 1 screw near the top of your plank.
Continue this pattern until all the top planks are in position.
Note at this stage your posts will still be loose in their respective holes.
Go back and after you have aligned each post properly, insert your second screw.
Fill in the soil and compact each post. Now fix all the other planks from the top moving down.
When all your planks have been securely fastened, fit your colonial handrail on the top.
The timber work on the terrace construction is now all complete.
Clear out the drainage furrow. Starting at your lowest point start hanging builder’s plastic down on the inside of
the terrace construction. Tack your plastic in a few positions at the top to keep it in place.
Lay down the next sheet of plastic and let if overhang 150mm from the previous plastic sheet.
Continue until the whole terrace has been covered on the inside.
Complete your drainage by placing the large stones and or pebbles in the bottom of the furrow.
Cover this up with a layer of sand. Fill up the terrace with soil.
Water your terrace down and leave the soil so it can settle. Don’t compact your soil.
You may now finish the rest of the garden in front of the terrace construction.
Paint the terrace to fit in with the rest of the garden, the home and surroundings.
Put a pot or plant in front of your drainage hole to hide it from view.
You could likewise soften the other corners of the construction.
After you have completed all this work, grab a garden chair, sit down and savour the moment.
Enjoy the satisfaction of seeing your own constructed new terrace and start dreaming
of all the nice plants you will soon be planting there!