How to support deckframe on a hardcore/ballast base ??

5 Jan 2006
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United Kingdom
(I think I have read pretty much every decking advice question on this forum but still havent found a response so am posting my own)

I'm putting down a decked area size 6m (house width) by 3.6m, so am starting to build a frame. I will have to use 75 x 50 as I dont have enough room below my french doors for anything bigger.

The area to be decked is 60% the old concete patio (very solid) and 40% a dug out area that has then been backfilled with old small broken bricks, ballast, sand etc (The original plan was to use this as a sub-base for a new paved patio).

For the part of the deck frame that will be over the hardcore area, what options do i have. Should i dig out and put posts into this and cement them in (as I would do if this was grass/soil)
or can i lay some paving slabs onto the hardcore and rest the joists on these to level the frame
or can should i concrete over the top of the hardcore and then have a firm base for the joists.

Finally, I've seen that I can raise the deck frame off the existing concrete patio using either wooden "legs", paving slabs, bricks on the patio, or bits of slate to pack the levels up. (Firstly is this correct, and which is the best method)
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Hi, I finished my decking over a concrete patio (see earlier post) last Dec. Used approx. 60 cheap bricks (10 p each) to support the 100 x 50 frame off the concrete patio. This has worked very well.

Had to lift some decking boards the other day to concrete in a 'water trap' left by the people who built my conservatory a couple of years ago (only found this cavity when I removed their step to replace it with decking). Everything under the decking has dried out very nicely, despite the bad weather we have had.

Good luck with your project.


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