This season I’ve been putting fiber mesh in the concrete I’m using for deck footings. My concrete guy only charges an extra $7 per yard to throw it in.
Does it really help the footings much? I normally use 10″ sonotubes set 48″ deep, occasionally with a Big Foot on the bottom. Do pours of this size benefit any from using the fiber mesh? Or am I running parallel with the guy touting his 3″ mudsills in that thread a week or so back?
To be entirely honest I only began doing it as a way of having one more thing to seperate me from “the pack” as a quality builder when selling and building jobs.
Replies
Your footing would benefit more with rebar in it than the fibermesh.
Couple #5 both ways near the bottom and one or more up through the body of the pour and a substantial embeded post anchor.
DP,
A 10" column of good mud without any reinforcing is , oh I dunno, 4 times (WAG) stronger than any normal deck would need.
RE the bigfoot, as long as the bottom 10" or so of concrete is a few inches bigger than the sonotube, it will resist uplifting.
>>having one more thing to seperate me from "the pack" as a quality builder
If you really want overkill and want to set yourself seperate, have your steel supplier make a three vert w/3"ells and 3 rings #3 rebar tower. Hold the bottom (end with ells) 3" off the bottom of the hole and the sonotube 10" off the bottom.
Probably wont cost any more than a bigfoot and fiber. $7/yd for fiber isn't much fiber anyway, but like you said it was just a 'talking point'.
SamT
A 10" column of good mud without any reinforcing is , oh I dunno, 4 times (WAG) stronger than any normal deck would need.
Correct for compression load Sam, but if the columns are subject to a shear loading then rebar can be a good idea.
IanDG
You're, maybe, thinking of a Richter 9 shear loading?
SamT
Not specifically, no. You could get shear loading if you've got a situation where you've got, say, a couple of feet of unconsolidated backfill on top of heavy clay. Any sideways force on the top of the column in that situation would exert a shear force where the column entered the clay soil.
IanDG
Edited 4/17/2004 8:56 pm ET by IanDG
fiber does not work in footing. fiber and rebar has two differnt job, fiber will replace wire mesh in slabs but never rebar.
I agree -- I didn't say otherwise.
IanDG
Hey Sam, your post was encouraging to me!
The columns I poured for enclosed porches on my place are on a continuous strip footer with 12" sonotubes. Three 60 grade #4 rebar in the footers and three vert 60 grade #4 in the columns - all tied together, carefully center spaced in the columns and 4,000 lb mix.
Just seat-of-the-pants enginerring on my part and I'm no concrete expert for sure!
Just shooting for my usual overkill...Something is what it does.
Well, the responses are about what I thought they'd be. Although I appreciated the advice, there's no way I'm putting rebar in my deck footings. Just thought I'd throw the fibermesh in cuz it was simple. Doesn't sound like it's even worth the $7 though. As far as the BigFoots go, they are NEVER my choice....they're a total PIA, but they do get speced by archy's from time to time.
DP, why no rebar? Just curious. It's SOP here to bridge the footer and column with at least one length.
I never met a tool I didn't like!
Nick,
Maybe it's a regional thing or sumptin', but I've never seen anyone use rebar for the average deck around here. I've never had a problem with any of my deck footings...that's some with no rebar, no fibermesh, no BigFoot. I'm really not looking to invest much into improving them since there really isn't much wrong with them......fibermesh was just a matter of nodding my head to my crete truck driver and writing the check $7, $14, or $21 heavy. Know what I mean?
"I've never seen anyone use rebar for the average deck around here. I've never had a problem with any of my deck footings...that's some with no rebar, no fibermesh, no BigFoot. I'm really not looking to invest much into improving them since there really isn't much wrong with them..."
Then what are you really trying to do?
If, as you say, there is no problem with doing it the way you and others have been doing it why do you want to spend the customer's money on fluff?
If you want to provide a serious upgrade then use the rebar. Fiber is for flatwork crack control, nothing more.
"Fiber is for flatwork crack control, nothing more."
Well now, that's the answer I was looking for. Now you can take that corncob out of your azz that seems to be making you so testy.
"If, as you say, there is no problem with doing it the way you and others have been doing it why do you want to spend the customer's money on fluff? "
What do you think I'm doing, upping my deck estimates by a whopping $14 to cover the 2 yards of fibermesh and getting rich off of it? Think I'll throw my boat on the water and take the rest of the day off with all this extra cash. I was asking if there was any benefit, maybe long term, to using the fibermesh.....your first statement that I've posted at the top was really all that was necessary but thanks for all the extra gobbly-gook.
my house weigh 1000 lbs per lineral foot. Most of yall know I work with engineers, so I ran it through the computer. with a foot thick , 18 inch wide footing on a sand clay with bearing of 2200 lbs per sq ft. My house need no rebar. But the building code required 2 #5
Edited 4/19/2004 8:32 pm ET by BROWNBAGG
The only reason for rebar in the pile foundations for a deck is to resist shear and Sam or Ralph's suggestions will cover that adequately.
The strength of the mix itself will cope with compression forces -- the fibre really isn't doing a lot, other than being a selling point!
IanDG