How should I replace the supports for my low deck?

Treetrunk45

Hi, I want to put in some kind of post/stirrup/stump to hold up the side of my deck. The bearers are currently sitting on a sleeper edge which is rotting and needs to be replaced. I'd rather not reinstate the sleeper edge as it is unnecessary for my landscape and will just rot again in the future. 

Ideally I would like to replace with something made of metal or concrete that will not rot again. Can anybody help me with a suggestion on how I might undertake this job and what the best materials would be?

Deck sits around 400mm off the ground underneath and the bearers are two pieces of 45x90mm treated pine. 

Thanks!

MitchellMc

Welcome to the Bunnings Workshop community @Treetrunk45. It's fantastic to have you join us, and many thanks for your question about installing a post support.

It looks like you'd need to jack up that beam and remove all the rotted debris and dirt underneath it. Once the beam is safely shored up, you could dig a footer hole underneath. Something along the lines of 400W x 400D x 400mmH should be appropriate. Fill this footer hole with concrete, level it off with the surrounding soil and wait for it to cure fully. You can then jack the beam up slightly higher than where you need it to sit and place a pedestal foot on the concrete footer. Adjust the pedestal foot to the correct height for your beam, and then lower the beam down onto it.

The benefit of using the pedestal foot is that it's completely adjustable, so you don't have to worry about getting your height right until the very end. You could use any number of post supports for this, but it's just a matter of getting their height correct in this limited space. The biggest issue you will face is trying to jack up this beam to remove the material underneath. If you have any doubt about how you'd do this, it might be best to call in the professionals as you don't want to damage the deck structure or cause injury.

Please let me know if you have any questions.

Mitchell