building deck, 2x8 or 2x10?, need help
14(w) by 16(L) feet , 18 inches from ground level, attached to house one side.
Want to use pier in-ground footings using sono tubes and attaching 2 beams on top of in, (no posts).
Will be using Cantilevered post types with joists hanging about 2 feet past beam.
My questions are:
1) since my deck is not too high (only 18 inches), can I use 2x8 for beams and joists? 16 feet length total can be ok to use 3 footings? or how many footings?
2) will 2x8 joist sitting on top of 2x8 beams are ok with spacing of 16 feets? or I can use 12 feet spacing? I just don't want to use 2x10 due to only 18 inches max height of deck, which leaves me with 3.5 inches pier above ground, 7.25 inches for beam, 7.25 inches for joists for a total of 18 inches and I have to figure out for water drainage also.
3)Will using 12 feet spacing makes it better vs 16 with 2x8 beams and joists?
If I have little bit more room above ground I would have no problem using 2x10.
4) what size of sono tubes I should be using? 6" or 8" diameter?
Any sugessions will be greately appreciated.
I am in Toronto area.