Inorganic joists deck

[Lowika]

So, we have torn up the 35-year-old patio. Really rotten in some places... Partly because the beams were lying directly in the soil or on the rock in some spots. This is hard to avoid as we have no desire for rock drilling or blasting. So to the question; is there any inorganic material to use for the beams?

 

[jonaserik]

Concrete slabs 300X300 are great for laying under the joists, feel free to place a tar paper between the joist and the slab as well. A bit tricky to get everything level, but it's doable.

 

[Jonatan79]

Paving stone instead of joists. So close to the ground you are asking for trouble sooner or later….

 

[Lowika]

Concrete slabs 300X300 can be perfectly placed under the beams, preferably put tar paper between the beam and slab as well. It's a bit tricky to get everything level, but it's possible.

If we want to avoid making the new deck at different levels, having stone+beam builds too much on height.

 

[Kane]

If we want to avoid making the new deck on different levels, it's way too much on height to have stone+joist.

Use pressure-treated wood again then. It lasted 35 years.

 

[jonaserik]

If we want to avoid making the new deck at different levels, it builds up too much in height to have stone+beam.

Just need to dig down to the right level. If it becomes a little low so that it connects to the lawn, then you can place a piece of platon mat straight down at the edge to protect the wood. It works well to prevent soil or other materials from sinking down underneath.

 

[Lowika]

The lawn is not the problem. The rock and the patio door combined are the problem You can't dig into the rock, and if I build up too much, we won't be able to open the patio door, and I don't want the deck in levels (will just end up stubbing my toes).

 

[Lowika]

And it's not lawn at the other end, it's a wall, and then the lawn is half a meter ABOVE the terrace (the lawn is higher than the house and the terrace).

 

[jonaserik]

Then you have problems, see if you can lay tiles instead. Alternatively, install joists directly on the ground with tar paper underneath. It might last a few extra years then.

 

[Stuff]

Run pressure-treated again. Buy those with NTR A classification for the studs that will have ground contact. They are classified to be suitable for placement in soil and in freshwater.