Great topic, I haven't seen a form thread, I come from many years of setting forms commercially. My main job was concrete tilt-up construction. I was a panel ringer and made myself damn good at it so they would keep me there. I was in charge of the building shape and panel shape. I also worked on layout a lot too. Carried several colors of chalk and when I got home I looked like an Xmas tree. I did a lot of detail and panel check as well.
The Concrete Formwork Thread
I just wanted to start a thread about formwork. I have been doing residential work for the last eight years (mostly finishing) and recently jumped into the world of commercial formwork.
I will start with a few basic tips for fastening wood to concrete.
- when fastening 2x material with tie wire and 3 1/4" duplex, keep the tie wire a 1/4" away from the bottom of the hole. This makes it easier for the nail to drive down to the head instead of it stopping half way and having to mash it down.
- if you have no 3/16" bit for the hammer drill you can use 1/4" bit and use two 3" common's instead of duplex and wire.
- for fastening 3/4" ply to concrete, two 2 1/4" commons works well with a 3/16" bit.
I will post some other tips I have learned later.
I will start with a few basic tips for fastening wood to concrete.
- when fastening 2x material with tie wire and 3 1/4" duplex, keep the tie wire a 1/4" away from the bottom of the hole. This makes it easier for the nail to drive down to the head instead of it stopping half way and having to mash it down.
- if you have no 3/16" bit for the hammer drill you can use 1/4" bit and use two 3" common's instead of duplex and wire.
- for fastening 3/4" ply to concrete, two 2 1/4" commons works well with a 3/16" bit.
I will post some other tips I have learned later.
1 - 20 of 49 Posts
Only two things you gotta know about building a concrete form.
1.) It's gotta hold concrete
2.) You gotta be able to wreck it.
Amazing how many times I've seen the second rule ignored. :laughing:
1.) It's gotta hold concrete
2.) You gotta be able to wreck it.
Amazing how many times I've seen the second rule ignored. :laughing:
So many guys are clueless in being able to set forms with the intention of stripping it. I've seen prefect pours ruined by laborers, because the carpenter didn't form it right.mudpad said:Only two things you gotta know about building a concrete form. 1.) It's gotta hold concrete 2.) You gotta be able to wreck it. Amazing how many times I've seen the second rule ignored. :laughing:
The stripping process should go very easy.
In direct response to the above:
When forming an interior wall in a "u" shape, or an elevator shaft, or box, etc...chase all your formply corners and be sure to make your long sheet two pieces for ease of stripping.
When forming an interior wall in a "u" shape, or an elevator shaft, or box, etc...chase all your formply corners and be sure to make your long sheet two pieces for ease of stripping.
Make sure your cut guy understands how to make cuts so all the tie holes line up on snap tie forms.
This was about 20 years ago so I think I'm safe. I once set pier bolts for columns for a three story building, a whole row of them about 1/4" off. I set the first column wrong and pulled off from it and the rest went wrong as well. I had to buy the iron workers two cases of beer to slot the
Column bolt plates. I don't think we were suppose to cut them, but the inspector didn't say anything and I kept my job.
Column bolt plates. I don't think we were suppose to cut them, but the inspector didn't say anything and I kept my job.
If the building is still standing I would say you are o.k.:laughing:This was about 20 years ago so I think I'm safe. I once set pier bolts for columns for a three story building, a whole row of them about 1/4" off. I set the first column wrong and pulled off from it and the rest went wrong as well. I had to buy the iron workers two cases of beer to slot the
Column bolt plates. I don't think we were suppose to cut them, but the inspector didn't say anything and I kept my job.
Man I tell you I really miss commercial form-setting. The only thing that kind of sucks, is when I drive by a parking structure and say hey kids look at the pretty parking structure your dad built I get no enthusiasm. :laughing:
When building columns on site with a single waler system, don't underestimate the importance of lacing and properly placed strongbacks.
We had an issue with this earlier this year as the columns weren't strongbacked on the lacing and the guys couldn't even vibe it...it started to blow out a bit.
So we had to hammer on the forms to vibe it. 16" square, 8' tall...all hammered.
PITA.
We had an issue with this earlier this year as the columns weren't strongbacked on the lacing and the guys couldn't even vibe it...it started to blow out a bit.
So we had to hammer on the forms to vibe it. 16" square, 8' tall...all hammered.
PITA.
Equally as important, don't underestimate the movement that the vibe creates. It adds a whole new element of required strength.asevereid said:When building columns on site with a single waler system, don't underestimate the importance of lacing and properly placed strongbacks. We had an issue with this earlier this year as the columns weren't strongbacked on the lacing and the guys couldn't even vibe it...it started to blow out a bit. So we had to hammer on the forms to vibe it. 16" square, 8' tall...all hammered. PITA.
Yes, and on that very important note: for site built columns over 8' in height: start your lacing at 12" spacing at the bottom, and work your spacing apart from there.Equally as important, don't underestimate the movement that the vibe creates. It adds a whole new element of required strength.
That's not a set rule, but it provides peace of mind and only requires a few more scraps of lumber.
We use the "key" the corners on columns, same thing you are describing I think. We also use a banding machine to tie pallets of used form materials with steel bands for flying to the next level.When building columns on site with a single waler system, don't underestimate the importance of lacing and properly placed strongbacks.
We had an issue with this earlier this year as the columns weren't strongbacked on the lacing and the guys couldn't even vibe it...it started to blow out a bit.
So we had to hammer on the forms to vibe it. 16" square, 8' tall...all hammered.
PITA.
I finally figure out applying a steel band at 16" centers is way better and cheaper/ faster than the keying on columns up to 30" x 30". After that we go to Symons steel forms.
There we go...if I could recommend anything to any aspiring former: use pre fabbed panels whenever you can.
I like the Logix (sp?) system.
I like the Logix (sp?) system.
Wow. So many replies so fast. I am really liking formwork so far. I am working on the curb/stair/architectural crew. All of the core work is done by other crews. They use the PERI systems. I am usually out of the rain because we are always under a slab. We also place most of the concrete we form too. It's always the hard to get to spots, buckets, shovels and wheelbarrows. The job is Telus Gardens in downtown Vancouver.
It has been a nice change from finishing. I have always liked structural work and there seems to be more than enough to keep me interested for a while.
Another tip they taught me.
- When pre-fabbing panels build your 2x4 wall 1/4" smaller than your plywood to ensure a tight fit. For example for a 4'x8' panel that will be laying flat build your 2x4 wall at 48"x95 3/4" and split the difference. The panels will butt up nicely and still nail together well enough.
It has been a nice change from finishing. I have always liked structural work and there seems to be more than enough to keep me interested for a while.
Another tip they taught me.
- When pre-fabbing panels build your 2x4 wall 1/4" smaller than your plywood to ensure a tight fit. For example for a 4'x8' panel that will be laying flat build your 2x4 wall at 48"x95 3/4" and split the difference. The panels will butt up nicely and still nail together well enough.
Little different where I came from, we as carpenters didn't touch the mud. As a matter of fact I used to kid the finishers when some would splash on me while on pour watch.Bencouver said:Wow. So many replies so fast. I am really liking formwork so far. I am working on the curb/stair/architectural crew. All of the core work is done by other crews. They use the PERI systems. I am usually out of the rain because we are always under a slab. We also place most of the concrete we form too. It's always the hard to get to spots, buckets, shovels and wheelbarrows. The job is Telus Gardens in downtown Vancouver. It has been a nice change from finishing. I have always liked structural work and there seems to be more than enough to keep me interested for a while. Another tip they taught me. - When pre-fabbing panels build your 2x4 wall 1/4" smaller than your plywood to ensure a tight fit. For example for a 4'x8' panel that will be laying flat build your 2x4 wall at 48"x95 3/4" and split the difference. The panels will butt up nicely and still nail together well enough.
Also done my share of curb and gutter too. Wasn't long until all we were forming was the radiuses because they got a curb machine. We used to call it Herb and Butter.
We just do the placing not the finishing. At least once a week I'm moving a few meters in whatever medieval fashion we need to to get the job done.
By curbs I just mean any wall from 2" to 4'. We also often install small amounts of rebar just to keep the concrete flowing.
http://www.telusgarden.com/TelusGarden.html
We are mostly working on the building on the far right. It is up to about level 8 right now. The 40 story one to the right is 7 floors deep in the parkade. 8 level deep parkade total.
If I can ever get my wife to help me post some pictures I will. I am technologically impaired.
By curbs I just mean any wall from 2" to 4'. We also often install small amounts of rebar just to keep the concrete flowing.
http://www.telusgarden.com/TelusGarden.html
We are mostly working on the building on the far right. It is up to about level 8 right now. The 40 story one to the right is 7 floors deep in the parkade. 8 level deep parkade total.
If I can ever get my wife to help me post some pictures I will. I am technologically impaired.
We do a lot of MEVA light panels here. They are all crane set. I have used doka peri and we still use symons for small stuff. I understand this is not a commercial forum but I'm just saying where my experience lies
Small tip for sono tubes and cages:
If you're cage is off kilter you can center it with tie wire near the top. Take a nail, punch a hole in the side near the top of the cage, pass the wire through and around the cage and back through the hole. Loop the 2 ends around the nail you used to punch through with and twist the wire until the cage is where you want it. Repeat this process 3 more times around the sono tube.
Of course if you have chairs or another method of accomplishing this, this is irrelevant.
If you're cage is off kilter you can center it with tie wire near the top. Take a nail, punch a hole in the side near the top of the cage, pass the wire through and around the cage and back through the hole. Loop the 2 ends around the nail you used to punch through with and twist the wire until the cage is where you want it. Repeat this process 3 more times around the sono tube.
Of course if you have chairs or another method of accomplishing this, this is irrelevant.
I like this thread!
No other thread like it here.
I agree with keeping the studs at panels break back 1/8" to allow tight panel joints.
When building forms on site with snap ties.. don't build panels.. attach the bottom plate and use studs that extend at least above the top set of walers. Avoid cutting lumber and at the end it comes apart in easy to move sticks.
Also, run walers long at outside corners and at the end of walls.. At the corners run 2x4's vertical and nail perpendicular to concrete pressure, and at the end of walls run vertical 2x4's again and use a "dry tie" on the outside of the bulkhead.
While we are it.. Lets talk about layout.. I have been really fascinated by the layout techniques that commercial forming guys use.
No other thread like it here.
I agree with keeping the studs at panels break back 1/8" to allow tight panel joints.
When building forms on site with snap ties.. don't build panels.. attach the bottom plate and use studs that extend at least above the top set of walers. Avoid cutting lumber and at the end it comes apart in easy to move sticks.
Also, run walers long at outside corners and at the end of walls.. At the corners run 2x4's vertical and nail perpendicular to concrete pressure, and at the end of walls run vertical 2x4's again and use a "dry tie" on the outside of the bulkhead.
While we are it.. Lets talk about layout.. I have been really fascinated by the layout techniques that commercial forming guys use.
1 - 20 of 49 Posts
- This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Contractor Talk - Professional Construction and Remodeling Forum
A forum community dedicated to professional construction and remodeling contractors. Come join the discussion about the industry, trades, safety, projects, finishing, tools, machinery, styles, scales, reviews, accessories, classifieds, and more!
Full Forum Listing
Explore Our Forums
Recommended Communities
