We recently had a national chain home improvement store design a deck for us. It will be 14' x 20' and about 24" tall. They designed it with 2 20' beams spaced 2' in with 10' between them for support and only using 8 Dek Blocks under the beams to hold everything up. After reading on here a little, it looks like that isnt even close to being enough blocks?? Do things change alot when using beams instead of just joists?

You do not have enough blocks and should not build a deck with that plan.

We hear about this from time to time. A national chain building supply center designs a plan with their software that uses far less blocks than we recommend. This is becoming more rare and in many cases they request a plan from us rather than use their own software. Typically the software they use calls for too few blocks and will result in a deck with problems. Decks build with post and beam construction, while use blocks, can be very wobbly, shaky, and unstable. They do not spread the weight of the deck out enough and the deck could settle.

Deckman