One of my projects this summer is to replace our rotten decking. I've taken up a couple of the old planks and it's obvious why it rotted - the frame is resting directly on what looks like the hardcore foundations of a former patio. In some place it's directly on dirt.
The problem I have is that I need to keep the top of the new frame within that 100mm (4") for the new decking to fit with the patio doors. Any taller and the doors would not open.
I don't want to have to dig through hardcore and fit a large amount of posts, so what I was thinking was to use the 50-80mm adjustable plastic rises and 50x50mm pressure treated joists. I read that this would be ok if I use a post every 50cm instead of every 75cm if I had the 100x50mm wood.
A couple of friends mentioned the words trampoline and said it would not last. Does anyone here know if that is the case? How about if I used the 100x50mm on its side but keeping the closer 50cm posts (though I bet you can't get joist hangers like that).
Or should I be doing something entirely different. This is quite a big deck and I really don't think that digging and filling 100 post holes is practical
The problem I have is that I need to keep the top of the new frame within that 100mm (4") for the new decking to fit with the patio doors. Any taller and the doors would not open.
I don't want to have to dig through hardcore and fit a large amount of posts, so what I was thinking was to use the 50-80mm adjustable plastic rises and 50x50mm pressure treated joists. I read that this would be ok if I use a post every 50cm instead of every 75cm if I had the 100x50mm wood.
A couple of friends mentioned the words trampoline and said it would not last. Does anyone here know if that is the case? How about if I used the 100x50mm on its side but keeping the closer 50cm posts (though I bet you can't get joist hangers like that).
Or should I be doing something entirely different. This is quite a big deck and I really don't think that digging and filling 100 post holes is practical