Where should I put stumps under my deck?

[AWolff]

Unfortunately the previous owners of this house built a deck straight into the ground. the wooden stumps have rotted as there was no concrete or anything used. So I have taken off the decking boards and removed the built up soil and now am left with the above pictured structure that I would like to add stumps to. How many should I add, where, how deep? Should I use stirrups? The grey spots are locations I considered putting stumps. The frame is attached to the house and not very high off the ground (5cm) so getting stirrups under the wood is a bit tricky but possible if i dig the holes wide enough. Appreciate any help. Thanks!!

[AWolff]

So i could make them as wide as i want in one direction (under the deck) but not in the direction away from the deck as there is concrete, especially concrete thats holding up the supports for the roof which would go fairly deep, as pictured. it affects 4 stumps to some degree. 

[JacobZ]

Hi @AWolff,

As I said, it's not ideal, but as long as the stirrup is fully encased and it is deep enough, it should be ok. You'd want to make sure there is at least 50mm of concrete on each side of the stem. If you can't do this, then you may be better off just pouring some concrete and using a bolt-down post anchor.

If you were to go with this method, then you would need to pack out the stirrup, as they do not come in half stirrup versions. You could simply cut a piece of 90 x 45mm H3 Treated Pine and sit it in the stirrup with the bearer, then bolt through both.

Let me know if you have further questions.

Jacob