Timber Decking on Top of Concrete

My client has asked me to build a timber deck for them, when I met up with them I suggested that it was better for me to pour the concrete slab and put the decking on top. The reason for this is when you build a deck you should have a minimum clearence of 300mm or 1f from the lowest part of the deck which would be the bearers to the top of the ground. In this case alot of dirt would had to of been removed.

Step 1: Marking Out the Batterns

Im Using 90 x 19mm Merbau decking and the maximum joist spacing or decking can span between each joist is 450mm
We have simply marked on the ground where each battern will be laid.

Make sure when using timber outside that the timber is either Treated Pine or hardwood.
Im using Treated Pine 70 x 45 mm

Step 2: Setting the Height of the Batterns

With the decking I am going to make the top of the decking flush with the top of the pre exististing Grey concrete and to achieve the exact height I am using plastic packers, they come in the shape of a U and also comes in various thicknesses.

Step 3: Fastening the Batterns

Pre drill with a 25mm spade bit 15-20mm deep.
with a 10mm concrete drill bit drill a hole in the concrete.
place a Galvanized Dyna bolt (galvanized is used for external use and will not rust. I you live near the ocean or a beach you will need Stainless steel dyna bolts).

Place the dyna bolt in the hole and tighten.

Step 4: Setting All the Batterns

Set the first battern so that it is level and staright. Then skip about 4 batterns and do the same to the other.

Using a straight piece of aluminum or what is better known as a Straight Edge. Run that perpendicular to your batterns and use that as a guide to get the battens in between at the same level.
Repeat this step as many times as required depending on the size of your Deck.

Step 5: Laying the Decking

In this step by step guide I have demonstrated that timber decking can go straight over the concrete even if the concrete is not level it is important to make sure that your batterns are level.



In my previous how to build a deck I have a step by step guide to laying the decking boards.

If you have any questions please do not hesitate to email me.

Step 6: Finished Product