reusing old peir footers - DIY Chatroom

rtoni · 07-27-2009, 05:08 PM

I just rebuilt a couple of the old piers in my camp. new pier (bigfoot and sono tube) replacing a square concrete pad (24" x 24" x 8" thick) that sat just under the surface of the ground.

I'm thinking of reusing these old pier footings for a small deck. If I do, I'm wondering if / how I should attach a new concrete post (sono tube) to the top surface? should I drill the top center footer and stick a piece of rebar out / up into the tube? Or do I even need to worry about this?

thanks

Wildie · 07-27-2009, 07:51 PM

Quote:

Originally Posted by rtoni

I just rebuilt a couple of the old piers in my camp. new pier (bigfoot and sono tube) replacing a square concrete pad (24" x 24" x 8" thick) that sat just under the surface of the ground.

I'm thinking of reusing these old pier footings for a small deck. If I do, I'm wondering if / how I should attach a new concrete post (sono tube) to the top surface? should I drill the top center footer and stick a piece of rebar out / up into the tube? Or do I even need to worry about this?

thanks

Do you have any frost considerations? Footings should always be below the frost level.
Footings should not rest on disturbed ground. If you clear the hole down to undisturbed earth, spread some masonary cement over the earth and then lay the old footing in the mortor bed, it should work!

rtoni · 07-28-2009, 10:42 AM

Thanks Wildie - I'm in Northern Ontario (Canada) so frost is a given. I was thinking of digging down and placing the concrete pads down in the hole, then sitting sono tube on top of the pad, then backfilling and mixing some concrete for the tube. What I'm not sure about is how to "fix" the concrete in the tube to the footing (or if I even have to worry about that). I didn't know about using a mortar bed - I do have a couple extra bags of masonry cement left over - is this to help stabilize or level the pad?

Wildie · 07-28-2009, 01:45 PM

Quote:

Originally Posted by rtoni

Thanks Wildie - I'm in Northern Ontario (Canada) so frost is a given. I was thinking of digging down and placing the concrete pads down in the hole, then sitting sono tube on top of the pad, then backfilling and mixing some concrete for the tube. What I'm not sure about is how to "fix" the concrete in the tube to the footing (or if I even have to worry about that). I didn't know about using a mortar bed - I do have a couple extra bags of masonry cement left over - is this to help stabilize or level the pad?

I'm in S.ON. so can appreciate your situation.

I just underpinned a concrete porch. I had to undermine the foundation and dig down to the 48" mark for a footing to satisfy the inspector. I poured 16" footing then used a Sono tube up to the old foundation base.
The mortor bed will compensate for irregularities in the excavation and allow for the slab to be leveled off. Then, it hardens to give the support that you require.
I do wonder about using the old bases as they should be placed down 48". It would be much easier just to pour in fresh cement in the hole and let it set up.
Maybe you should save the old footings for something like a wood shed!

rtoni · 07-28-2009, 02:52 PM

Quote:

Originally Posted by Wildie

Maybe you should save the old footings for something like a wood shed!

you know, that's not such a bad idea - lots of wood right now cut / split / scattered all over the place - wood shed is another project on the list - thanks for the sanity check...

Wildie · 07-28-2009, 08:21 PM

Quote:

Originally Posted by rtoni

you know, that's not such a bad idea - lots of wood right now cut / split / scattered all over the place - wood shed is another project on the list - thanks for the sanity check...

concretemasonry · 07-28-2009, 11:05 PM

Depending on your soil, it may be possible to dig much smaller hole to the proper depth and insert a Sonotube and pour it to the proper elevation, then insert a post connector into the wet concrete for your post. Trim the excess cardboard. Much less digging and probably less concrete.

For a small deck and decent soil the hole does not have to be very large in size and the depth will be the same. Bel bottoms are not always needed unless the soil is bad.

I am sure you know the footers you have will weight about 400# and are tough to handle.

The option is digging a hole much wider is a lot of trouble.

Dick

rtoni · 07-29-2009, 12:49 PM

Quote:

Originally Posted by concretemasonry

For a small deck and decent soil the hole does not have to be very large in size and the depth will be the same. Bel bottoms are not always needed unless the soil is bad.

I am sure you know the footers you have will weight about 400# and are tough to handle.

The option is digging a hole much wider is a lot of trouble.

Dick

yeah - somethings are hard on the back but I'm always thinking of re-use / recycle (budget is always really tight).

from what I've seen so far (anywhere I have dug) I have about 6" of "topsoil" (thick heavy organic mat'l), followed by about a foot of loose sandy gravel (pit run, small boulders), then about 2' of shale, sandstone, + wet mucky crap / red clay all mixed in (usually have to break this up - pretty messy) - then about 3-1/2 or 4' down I hit a fairly hard dry clay layer (have to scrape away at it with a shovel / bar to peel it up). This layering is pretty consistent across the area where I've been working so far. Does this sound like something that would support a smaller concrete post without the bell bottom? I think I could park a tank on that clay layer but the ground water (lots of rain this year) has seeped into the bottom of a couple of the holes I've opened up, so it does get saturated I'd guess.