Board-Formed Concrete - Concrete & Paving - Contractor Talk

Board-Formed Concrete

 
Thread Tools Search this Thread Display Modes
Old 05-02-2015, 12:06 PM   #1
Stonemason
 
bytor's Avatar
 
Trade: masonry
Join Date: Jan 2010
Location: Ontario
Posts: 639
Rewards Points: 616

Board-Formed Concrete


Hi all,

We are currently roughing in 3 large fireplaces for a custome home on an island property. We' ve been asked to complete the project by cladding the fireplaces in "board-formed" concrete.

We've done a little bit of this type of thing in the past, but never on such a scale. Each of the fireplaces is 10 feet wide by 3 feet deep and roughly 30 feet tall. All four sides are to be clad in concrete as the glass walls of the house abut the fireplaces on either side. There is of course a small break in the concrete at ceiling/soffit height.

Because we are dealing with an island location, the logistics of getting concrete trucks and pumps to the site are difficult... Not impossible, but difficult. Secondly, it is unlikely that we would be able to pour everything in 1 shot... Perhaps not even in two or three phases... So, pretty much resigning ourselves to mixing on site the old-fashioned way... Portland/concrete gravel etc.

We are likely going to purchase a small pump of some kind... We are considering a portable grout pump made by 'Airplaco' which will handle 3/8 or 3/4 aggregate depending on the model.

We will be using rough-sawn pine planking for the forms. The boards will be run through a wire-brush machine or sandblasted to really bring out the grain of the wood.

Of course we will be doing a few large sample panels to ensure that we can produce a reliable, repeatable mix and placement method.

So...

Any words of wisdom you would care to share?

Specifically, thoughts on appropriate aggregate size, mix profile, placement methods... Previous experiences good/bad with board formed concrete...

I'm certainly not up on all the latest regarding concrete. Should we be considering specific additives for our mix? i.e. To increse slump/workability without increasing water content.

Any thoughts on the Airplaco grout/concrete pumps would also be appreciated.

Thank you.

Last edited by bytor; 05-02-2015 at 12:08 PM.
bytor is offline  

Warning: The topics covered on this site include activities in which there exists the potential for serious injury or death. ContractorTalk.com DOES NOT guarantee the accuracy or completeness of any information contained on this site. Always use proper safety precaution and reference reliable outside sources before attempting any construction or remodeling task!

   

Advertisement

 

Old 05-02-2015, 12:32 PM   #2
Pro
 
artisanstone's Avatar
 
Trade: Stonemasonry
Join Date: Nov 2007
Location: upstate, sc
Posts: 663
Rewards Points: 662

Re: Board-Formed Concrete


Bytor, I'm no concrete guy, but the first thing that occurs to me is maybe they would accept precast panels. That way if something goes a little wrong in the pour, you just chuck the faulty piece and don't have to demo the cast in place concrete. Also would eliminate extensive formwork, pumps, etc. I would be comfortable handling 16 SF panels at 2-2.5" thick...

Advertisement

artisanstone is offline  
Old 05-02-2015, 03:54 PM   #3
Pro
 
JBM's Avatar
 
Trade: Masonry
Join Date: Mar 2011
Location: Mass.
Posts: 7,620
Rewards Points: 9,330

Re: Board-Formed Concrete


We had someone looking for the same thing a couple years ago, they hired someone else but I was going to use the concrete as a 4" veneer after the blockwork was done. My pal was going to handle the forming of it in sections, tongue and groove something like they make ceilings out of. Bout as far as I got.
JBM is offline  
Sponsored Links
Advertisement
 
Old 05-02-2015, 06:19 PM   #4
Pro
 
fjn's Avatar
 
Trade: mason
Join Date: Aug 2011
Posts: 5,019
Rewards Points: 10,676

Re: Board-Formed Concrete


Since this is a one side form and pour,you will need some stout bracing to withstand the hydro-static pressure imposed on the forms. For I'AM sure they do not want to see form ties. I would use a plastisizer to enhance flow without increasing slump. Do not forget to vibrate,consolidate the concrete. Honeycombs would undoubtedly wreck the hole thing.
fjn is offline  
Old 05-02-2015, 07:30 PM   #5
Pro
 
fjn's Avatar
 
Trade: mason
Join Date: Aug 2011
Posts: 5,019
Rewards Points: 10,676

Re: Board-Formed Concrete


I looked at the pump co. you posted. Unless I viewed it wrong,you cannot pump a pea gravel mix. I would think a pea gravel mix would be what the Dr. would order.
fjn is offline  
Old 05-02-2015, 07:52 PM   #6
Registered User
 
StainConcrete's Avatar
 
Trade: Concrete
Join Date: Nov 2012
Location: Washington, MO
Posts: 8
Rewards Points: 18

Re: Board-Formed Concrete


Wow. Lots of things to consider here. 30' tall single form, 4 sided?

Sounds awesome! I love it. A challenge indeed.

I would look for a pre prortioned mix (bag mix) of high quality for this application. Think of water reducers, plasticizers to reduce the need for mix water if you were forced to mix this.

it would be preferable to use ready mix through a grout pump (pea gravel) likely a high strength mix with a ton of dope (water reducer)

The form work is what I'm interested in. Please post pics of that!

Last edited by StainConcrete; 05-02-2015 at 08:02 PM. Reason: Needed to add the info asked for
StainConcrete is offline  
Old 05-03-2015, 06:14 AM   #7
Pro
 
CJKarl's Avatar
 
Trade: Masonry
Join Date: Nov 2006
Location: Ivoryton CT
Posts: 4,289
Rewards Points: 3,926

Re: Board-Formed Concrete


I've worked on a job just like this. I didn't do the crete work, but all the other masonry including building the fireplaces in the already poured chimneys.
As far as the formwork they lined the panels with sandblasted wood as mentioned. They were laid in meticulously as the owner was CRAZY about continuity in the joints. They started with some type of plastic or fiberglass tie, but in the larger pours they were breaking so the went to steel which is now problematic because of rust. The chimney was poured in two stages.
__________________
There's Always A Market For Quality
http://www.kaufmannmasonry.com/

Last edited by CJKarl; 05-03-2015 at 06:16 AM.
CJKarl is offline  
Old 05-03-2015, 06:15 AM   #8
Pro
 
CJKarl's Avatar
 
Trade: Masonry
Join Date: Nov 2006
Location: Ivoryton CT
Posts: 4,289
Rewards Points: 3,926

Re: Board-Formed Concrete


Sounds like another one of a kind Bytor project.
__________________
There's Always A Market For Quality
http://www.kaufmannmasonry.com/
CJKarl is offline  
Old 05-03-2015, 08:59 AM   #9
building Contractor
 
FHS's Avatar
 
Trade: General Contractor
Join Date: Apr 2010
Location: Albert City, IA
Posts: 235
Rewards Points: 160

Re: Board-Formed Concrete


This fireplace is 10' wide, 18" deep and 23' tall. We skim coated with concrete instead of pouring. We used Butterfield MT resurfacer, then stained and sealed.
Attached Thumbnails
Board-Formed Concrete-1430661382071.jpg  
__________________
Tim Fuchs Construction
FHS is offline  
The Following 2 Users Say Thank You to FHS For This Useful Post:
CConcreteEx (05-03-2015), fjn (05-03-2015)
Old 05-03-2015, 09:16 AM   #10
Pro
 
mako1's Avatar
 
Trade: remodeling
Join Date: Sep 2013
Location: Illinois
Posts: 2,517
Rewards Points: 1,094

Re: Board-Formed Concrete


Would'nt it be easier and quicker to form with ply with architectural panels attached to the inside?We used the process in FL for exterior sheerwalls going 20 floors.
mako1 is offline  
Old 05-03-2015, 11:29 AM   #11
Pro
 
fjn's Avatar
 
Trade: mason
Join Date: Aug 2011
Posts: 5,019
Rewards Points: 10,676

Re: Board-Formed Concrete


Quote:
Originally Posted by FHS View Post
This fireplace is 10' wide, 18" deep and 23' tall. We skim coated with concrete instead of pouring. We used Butterfield MT resurfacer, then stained and sealed.




Looks very nice. Furthermore,sounds like a great idea. The architectural board formed concrete I did ,the specs. called for no visible snap ties. The bracing to pull that off was a challenge and a half.
fjn is offline  
Old 05-03-2015, 12:01 PM   #12
CCC
 
CConcreteEx's Avatar
 
Trade: Concrete
Join Date: Oct 2010
Location: Abq
Posts: 275
Rewards Points: 537

Re: Board-Formed Concrete


Could you rent a mixer truck. One of the ones that mix and add all the materials onsite and then mix at the same time?
CConcreteEx is offline  
Old 05-03-2015, 12:11 PM   #13
Pro
 
mako1's Avatar
 
Trade: remodeling
Join Date: Sep 2013
Location: Illinois
Posts: 2,517
Rewards Points: 1,094

Re: Board-Formed Concrete


Quote:
Originally Posted by fjn View Post
Looks very nice. Furthermore,sounds like a great idea. The architectural board formed concrete I did ,the specs. called for no visible snap ties. The bracing to pull that off was a challenge and a half.
Figure it might be.We used Simon forms and know it was very expensive then.Simon forms would be more rigid and take less bracing but still a challenge and expensive.We had all our own forms so that helped.
mako1 is offline  
The Following User Says Thank You to mako1 For This Useful Post:
fjn (05-03-2015)
Old 05-03-2015, 06:42 PM   #14
Pro
 
JBM's Avatar
 
Trade: Masonry
Join Date: Mar 2011
Location: Mass.
Posts: 7,620
Rewards Points: 9,330

Re: Board-Formed Concrete


If It were me I would approach this as possibly a multi, multi day, week(2) long pour. There is no hurry right, people have the money to do it right, so make a big ass form and slide boards down on it, do 5' a day-whatever. Do the chimney first and pour 5'. No pressure really, next day add more boards pour. Not sure how to get the best finish, but I would feel confident I could take forever to do this thing and have it come out right

Advertisement

JBM is offline  


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Sealing Stamped Concrete Bill Butler Masonry 1 06-02-2013 04:51 PM
whats your ledger board flashing detail? Rich D. Decks & Fencing 77 10-24-2012 07:08 PM
The war of plywood VS particle board Jimmy Cabinet Kitchens & Baths 47 09-18-2012 07:52 AM
TYPARŪ Flashing BA - under a concrete floor?? AmeliaP Masonry 5 07-27-2012 04:08 AM
Concrete with Fly Ash vs. Concrete without? cdkyle Concrete & Paving 19 07-28-2010 09:57 PM

Join Now... It's Fast and FREE!

I am a professional contractor
I am a DIY Homeowner
Drywall Talk is for
PROFESSIONAL CONTRACTORS ONLY!

At DrywallTalk.com we cater exlusivly to professional contractors who make their living as a contractor. Knowing that many homeowners and DIYers are looking for a community to call home, we've created www.DIYChatroom.com DIY Chatroom is full of helpful advices and perfect for DIY homeowners.

Redirecing in 10 seconds
No Thanks
terms of service

Already Have an Account?