Decking – the usual method

Garden Decks, we love them and they have been growing in popularity ever since i started working in this industry. We have a range of different options to suit any situation and a great knowledge base on their construction. Decking is an affordable way to transfer a space in your garden into a useable space.

We have a very helpful advice section below for those that choose to take on such an endeavor, Please enjoy

Decking Installation Guide:

I’ve been asked a lot recently about our garden decking and especially how it is installed and on what sort of base, so I thought a short guide maybe helpful to our customers.  Of course it’s also a plug about our products, our composite decking is proving very popular as are our decking tiles and decking boards.  Interestingly sales  for the composite decking is increasing month on month

Composite decking

Composite decking

As a quick guide I suggest the following, of course there are lots of ways of accomplishing the same thing but this, I hope, is a good guide or at least gives you a few pointers.


Like any project, planning is the most important part, it shouldn’t be overlooked, what’s the old saying?  The five ‘P’s’:  Planning Prevents Pi – –  Poor Performance!

So, first make a rough drawing of your design, laying out pieces of wood to mark the edge of the planned decking always helps me to visualise how it will look.  Decking board at right angles helps to draw your eye into the house, board’s parallel show off the width of the decking.

It’s a good idea to make a scale drawing and also add the house walls, openings, obstacles etc.  If you’re attaching the deck to your house always make sure that the attachment point is 150mm below the damp proof course.  Make sure as well, you allow access to inspection covers and importantly don’t block air vents.


Using your scale drawing calculate the area of the deck.  Divide the area of the deck by the size of the decking tiles you are using or the timber / composite decking planks.  Remember you will have to include spaces for expansion and drainage between planks, I tend to use 5mm as a guide.

If you need help calculating what is required please do contact us.

Ground Work

Decking is usually built on a framework supported by concrete footings.  It can either be simply placed at ‘ground level’ or if needed ‘raised’ using uprights.

First it’s a good idea to use pegs and string to set out the deck perimeter.  Clear all turf and vegetation and firm the ground if needed.  It’s a really good idea to lay weed inhibiting membrane down on the area at this point to stop any nasties coming through.

Decking Frame

The framework should be put on concrete foundations.  You could lay concrete for this but slabs are a lot easier.  Slabs would normally be placed in a grid pattern about 1400mm apart to allow for adequate support for the joists.  If you have bad drainage or poor soil condition consider using poured concrete in holes of at least 300mm square.  Use a spirit level and try to make sure the deck slopes (away from the house) roughly 10mm for every meter.

Create the outer frame of the deck with pressure treated, tanalised timber.  150mm x 50mm is ideal.  Where the timber touches the ground use a damp proof course membrane.  In our ‘ground level’ method these joists will simply be placed on the ground being supported by the concrete grid.  For the ‘raised’ method these will be supported by uprights, I recommend 90 – 100mm sq tanalised timber.

With the frame in place use at least 100mm screws and wood glue to fix it together.  If the decking is being attached to the house make sure you add plenty of spacers to allow for a drainage gap.  Stainless steel washers are excellent for this.  Next you will infill the outer frame with joists spaced at 400mm intervals.  These should be at right angles to the finished decking tiles or boards.  You could use off cuts of timber to create noggins in between the joists for extra strength.

Laying the Decking

Once your framework is complete and totally rigid you can start laying your decking boards or tiles.  Lay about 6 boards at a time, I have already mentioned an expansion gap and to accomplish this evenly I tend to use a decking screw as a spacer (remove after fixing).

A few notes on fixing your decking boards:

  • Always use stainless steel or galvanised screws, there’s nothing worse than seeing rusty screw heads and stained decking boards.
  • Always pre-drill your screw holes, without this you run a risk of splitting the timber.
  • Screw the end of the boards first and then to every joist.
  • If the decking boards are wider than the deck you must make sure you stagger the boards and that joints are over a joist.

Raised Decks

Raised decks are slightly trickier and need a little bit more thought.  As I mentioned you will be using uprights of about 100mm square.  These will be held in place using metal supports of either a bolt in style or an adjustable concreted anchor.

Bolt down post anchors

Bolt down post anchors


Concrete anchor for posts

Concrete anchor for posts


The frame is constructed as above but will be utilising joist hangers for added strength.

If the deck is over 60cm in height we strongly recommend a rail to prevent a nasty fall.

Also, any cut timber or drill holes would benefit from a timber treatment

I hope this has been helpful.  If you need any help or advice with your decking project please contact us

This entry was posted in Decking and tagged , , , , by Richard. Bookmark the permalink.

About Richard

This blog is my personal platform which I do enjoy. It is my own viewpoint and my own ideas. I may not be right and other installers / experts may offer a different view point or a alternative way to do something. I welcome contributions from anybody experienced to do so.

All my blog writing is MY OWN personal opinion ONLY and is NOT always the opinion of TUIN | TUINDECO as a company.

Log Cabins and Garden timber have a myriad of intricacies , I love to give away the secrets, there are a lot!

I enjoy using this blog to expose them so you know what you are buying. I love to know I am causing a few problems in the industry as it can be on occasions less than honest.

I actively encourage everyone to install their own buildings. So many times I would fit and the company I was working for would charge loads for my time, only then to be faced with the embarrassment when the customer says 'I could have done that' and YES you can without paying hundreds of Pounds!

I have over 19 years experience within the garden timber industry. I have particular expertise in garden buildings including the manufacture, design and installation from sheds to log cabins and all the way up to timber framed houses.

In my time I have been involved with virtually every manufacturer and supplier of garden buildings. I have also installed pretty much every make of Garden Building there is from ALL suppliers and manufacturers.

Prior to my career change I was a Watch Commander in the Fire Service with particular expertise in chemical incidents, training, technical design / technology / IT /Procedures / ISO Systems and road traffic accidents. I retired due to a nasty injury after 20 years service.

During my time in the Fire Service, on my days off, I was a self employed fitter for any type of garden building, I worked with most of the well known companies as a subcontractor.

I now work with Tuin | Tuindeco in the UK, supporting and advising on the vast range of products. I keep an eye out for help requests when we a supposed to be closed and can usually get back to you out of hours via email only (wife and children permitting on my days off).

In my private life I consult as an independent expert assessor for companies or private individuals when a dispute is present over their structure which results in producing an impartial report and assessment for whoever requires it. This is often higher valued than a structural engineers report born from my credentials, experience and widely recognised as an 'Expert' in the field.

I am a freelance writer for numerous companies, publications and blogs as well as an independent expert and fault finder for parts of the Industry and consumers with a particular emphasis on timber structures, both framed and of an interlocking design such as log cabins.

I produce numerous articles about timber in general, information on general timber products and specific guides when needed. I hope you enjoy and find my writing useful.

Please contribute and comment to my posts as you would like and I will try to respond as best I can.

Thank you


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