Laying deck on old built up patio area, Help!

[stustu92]

Hi all,

I have a patio outside my french doors which is built upto the same level as the internal floor. the garden is sloping away from the house, so the far end of the patio is about 0.7 metres deep, the whole patio has a small wall built around it. I am lifting the patio and getting rid of the backfill etc which is in the built up area to expose the air bricks and to eliminate a drainage problem.

My question is this: I plan to lay the deck at the same level as the patio was previously with nothing underneath the deck. This should enable air to flow underneath the deck and ventilate under the floor in the house, i hope. I'm using 4x2 inch timbers as support to lay 38mm deck boards onto. I'm fastening the support timbers onto the internal faces of the built up area using joist hangers. What is the maximum space i can allow between support timbers?

Does this all sound ok?

 

[Thermo]

put some decent landscaping fabric under the deck to stop weeds growing. Support the boards at 400 mm centres. otherwise sounds ok

 

[stustu92]

The area i'm decking is 5.5 metres along the house wall and 3m away from the house.
I plan to put the support timbers running parallel with the house so that the deck boards run away from the house. The longest treated support timbers i can get are 4.8 metres long, so i'm going to need to splice the timbers.

How much do i need to overlap them or is there a better way?

 

[Thermo]

it would be easier to build the frame as two seperate frames and bolt them through where they join with a double joist. That way you wont need to splice the joins, which will make it quicker and stronger. You can also use shorter and more manageable timbers