Home & Garden

Concrete Footings for a Deck

  • Last Updated:
  • Jul 13th, 2020 1:33 pm
Tags:
[OP]
Deal Addict
Jul 22, 2019
2429 posts
3203 upvotes

Concrete Footings for a Deck

If anyone can help recommend the best method for a deck. We have a very small 4x6 deck at the moment. Has 2 posts holding it up and attached to the house. I wanted to DIY expand the deck. Keep the same 5' width and extend it about 6' so the new deck would be 4x12.

What's the best way to do the footings? Existing one is 6x6 post into the concrete. I was thinking of doing something like this: Looks a little easier DIY. How does something like this last in the weather in the GTA?

Do I have to attach the new part of the deck into the house, or can I just attach it the existing deck, and have 4 posts in the ground holding it up?
4 replies
Deal Addict
User avatar
Mar 8, 2002
4232 posts
876 upvotes
Ottawa
If you put the concrete footing down four feet below grade using the technique pictured, it will last for decades. Slope the concrete top outwards so water can't sit on top.

You don't have to attach the deck to the house as long as it's supported correctly. Although this is too small for a building inspector to be bothered with, some inspectors would insist the posts are supposed to be at the edge of the deck with zero deck overhang allowed.
Deal Guru
Jan 25, 2007
11977 posts
7133 upvotes
Paris
MacGyver wrote: You don't have to attach the deck to the house as long as it's supported correctly. Although this is too small for a building inspector to be bothered with, some inspectors would insist the posts are supposed to be at the edge of the deck with zero deck overhang allowed.
Ive never heard this. There are tables for joist and beam size and the exact amount of cantilever allowed. Its one of the reasons I went with 2x12 beams.
Deal Addict
Jun 26, 2019
2003 posts
1734 upvotes
GTA
Jerico wrote: Ive never heard this. There are tables for joist and beam size and the exact amount of cantilever allowed. Its one of the reasons I went with 2x12 beams.
Yeah, lots of Cities/Municipalities have guidelines posted showing exactly what is allowed, this includes cantilevered sections.

Also, the deck footings you pictured are far better than ones with posts in the concrete itself. The post will rot in a matter of time then its a pain to deal with.

If you City has guidelines I would look them up to see all the requirements you are looking with.
Deal Expert
User avatar
Dec 26, 2005
16989 posts
1814 upvotes
Thornhill
If the others are poured footings (including attaching to the house) then you gotta do poured footings. There are other options where you embed a bolt into the concrete, then screw a deck mount onto the top of it - that allows you to rotate (or even raise?) it versus a one-piece post base.

In the GTA, the requirement is 4' down using a sonotube. I don't recall if it's required to be flared at the bottom, but would recommend it. Depending on the height/diameter ratio, you may want to insert rebar.

BTW, I had looked up the frost tables after I poured my footings and the frost level for GTA actually goes below 4' (e.g., 4-1/2' iirc?)... but I don't think anyone goes much beyond 4'.

bjl
What we do in life echoes in Eternity... and in Google cache.
RFD discounts for Schluter products

Top

Thread Information

There is currently 1 user viewing this thread. (0 members and 1 guest)