I want to build a deck over an existing patio and then extending further into the garden. It will be a simple 4m x 4m deck that is raised less than 50 cm from the ground. The question I have is that I don't want to pull up the existing patio but there is limited space between the existing patio and where the deck boards will be - 10cm at most. It is possible to lay the joists on the patio and then the deck boards on top but I am afraid that the joists will then start to rot because they are in contact with the patio and therefore water will pool against them. I was therefore thinking on putting a spacer between the joist and the patio which will allow water to run off.
Does this sound feasible?
What is the minimum height that the space should be?
Any good thoughts on what to use as a spacer?
Does it matter that the joist height will be greatly reduced? I am assuming that they are usually a certain height to support the weight of the deck. With the joists now supported on the patio is it ok that the height is less?
Does this sound feasible?
What is the minimum height that the space should be?
Any good thoughts on what to use as a spacer?
Does it matter that the joist height will be greatly reduced? I am assuming that they are usually a certain height to support the weight of the deck. With the joists now supported on the patio is it ok that the height is less?