Decking Joists -- 100mm or 150mm ?? & supports

[aimhigh]

Hi

I am building quite a large ground level deck (4.5m * 10m) and want it to be as low as is practical w/o removing too much soil.

What is the best advice about size of the decking joists ? should I stick with 150mm x47mm or is it Ok to go with 100mm x47mm ?? I would support them at 1m (or 1.2m spans) onto concrete blocks

Also does anyone have experience of precast decking piers ? they are expensive !!! but are they better

And finally, what is the view of composite decking out there ?

Thanks

R

 

[Thermo]

4 x 2 is fine, we use it all the time on ground level decks, just need some more support.

 

[aimhigh]

Thank you for your quick answer

 

[harryc]

Would the composite not be too slip when wet considering it is just plastic.

Why would you want to pay the extra cost for concrete piers when you can use engineered blocks.

Harry

 

[Thermo]

we use timber posts set in concrete, long lasting, no bounce and easy to level.

 

[aimhigh]

Thermo

would you do this for a ground level deck using 4x2 as you suggest ? rather than the concrete blocks ?
thx

 

[Thermo]

thats what i said! much easier to level the frame up as well.

 

[aimhigh]

thanks