I have 2 existing deck footings (no rebar in footing) that are weakened and crumbly on one side.
Can anyone advise me as to how to rectify, and strengthen, these footings?
Any help would be greatly appreciated!
Thanks in advance!
Why are the footings deteriorating? Unless these footings are massive or little more than cosmetically damaged, I'd recommend total replacement.
A footing without rebar is less strong, and if your deck is heavy or sagging, you need to replace your footing. Is the concrete in the footing crumbling?
An efficient temporary supports will hold the deck while you are replacing the footings.
Unless you are certain that some chemical reaction (like salt) is causing the problem, then it's likely that the entire concrete mix is going to crumble soon, so replacement is going to be needed. Also be sure the 'crumbly' part is actual footing and not just spillage around the footing which was left to dry in place. If that is your case then flake it away or cover it- it won't hurt anything since it's not part of the structural footing itself.
If you have to replace the footings, call the concrete company you plan to use for recommendations about the proper mix you'll need. You might also need a building permit and inspection- call and find out. The building codes Inspector will be glad to tell you what is required as to depth, width, and reinforcing as well as what points in the process they need to inspect things at.