Low timber deck over concrete.

[Purpleheart]

The brackets were a substitute for the last row of "stumps".

They are on old concrete slabs which go back under the deck about 400mm. The concrete in this area was nice and even, the rest of the(previously concreted) area it was rather crappy, so it (the concrete) had to go.

In the picts, the deck is only about 100mm above the conc, but with the conc gone (under the rest of the deck) it is about 250 above the NS.

If I had a level surface (of conc) to work with, and didn't want to build the deck too high, I wouldn't hesitate to use that method all the way through.

Since I am not a builder, I tend to over engineer anything I build, and I spaced the joists at about 400, and the bearers were closer than spec too (but I can't remember now), but I knew I wanted to put some heavy things on the deck (eg Solid Ironbark Picnic Table).

Another area of the deck had 25 stumps in a 3.5m sq area, but that was so we could put a spa on it.

Cheers....

[jonassen]

Morning,

I am building a low deck over concrete. Maybe 200 - 250mm high. It looks i can get away without doing bearers (I think) and just attach joists directly onto some sort of sadle.

I live at the Gold Coast and went to some display homes for ideas.

What one builder had done was use those metal rods with a thread and by the looks, drilled into the concrete, pushed in the rod, put a nut down to the bottom of the concrete with liquid nails at the base of it to hold it. Then at the top was a another nut underneath a metal plate to support the joist.

These were spaced about 450 - 600mm apart along the joist and the deck seemed as solid as a rock.

I thought this was ingenious for levelling the joist and only having to drill one hole for the joist support per sadle instead of two.

Has anyone else done this method?

If so did you drill into the joist so the rod goes into it a little. (I sort of imagine you'd have to.) there did not seem to be any glue or screws at the top plate though????

Great web site, just found it this morning!!!!! Great stuff fellas! (Ooops and Gals)

[jonassen]

g'day
YES IT IS A GREAT WAY TO DO IT
I AM ABOUT TO BUILD A TIMBER DECK OVER A CONCRETE SLAB MYSELV
AND I WILL DO IT THE SAME WAY
TO HIDE THE NUT I AM CUT A SMALL SQAURE IUT ON THE TOP OF THE JOIST TO RECESS THE BOLT, SO THE BOARDS STILL WILL LEVELED

[bpj1968]

If you use dried treated pine F7 you can use

90 x 35 joists. These can span 1000 for a single span or 1300 continuos span (Over 3 or more bearers)
90 x 45 joists. These can span 1300 for a single span or 1700 continuos span (Over 3 or more bearers)

That's 110 mm used (Joists and deck)

For bearers if you use 2 side by side 90 x 45 they can span 1200 between supports. that gives a total of about 200 mm high.

[Kyle]

If you use dried treated pine F7 you can use

90 x 35 joists. These can span 1000 for a single span or 1300 continuos span (Over 3 or more bearers)
90 x 45 joists. These can span 1300 for a single span or 1700 continuos span (Over 3 or more bearers)

That's 110 mm used (Joists and deck)

For bearers if you use 2 side by side 90 x 45 they can span 1200 between supports. that gives a total of about 200 mm high.

A good rule to use when building a deck is go 300mm less in your spans (ie. if you can span 1000mm. then only span 700mm). While you use more bearers and stumps the deck ends up rock solid with no bounce.

Also make sure the concrete your building on is good enough to handle it. Because if you need a permit the council may frown on you building on your old garden path.