Building concrete foundation forms, what to treat/cover them with?

[robc-airww]

I'm going to make some foundation forms, but having never made my own I have a few questions. I've looked at purchasing some steel ones, but for my needs this doesn't seem worth it. My thinking is that I could build them cheaply enough, but I'd like them to last. I know the traditional treatments are to use oil, diesel, or similar form release agents, but I was wondering if anyone has tried any less messy/stinky alternatives like painting them, or laminating plastic to them? Also, if i use HDO, do I need to use a form release agent, or is the coating on the HDO good enough?

[dave_k]

Re: Building concrete foundation forms, what to treat/cover them with?

Also, if i use HDO, do I need to use a form release agent, or is the coating on the HDO good enough?

The plywood won't last long without form release. I've used some plastic coated Baltic birch faces forms from Europe covered in some sort of plastic but we still used form release to get the most use out of the forms.

It's been a few years since I've done any formwork, talk to your local concrete accessories supplier, there may be some environmentally friendly alternative that doesn't smell so bad. I find the smell of fresh concrete and form release nostalgic, like fresh cookies ;-)

[Pushing Pedals]

Re: Building concrete foundation forms, what to treat/cover them with?

If you build your own, you have to know what tie system you will use and design that into your form. You have storage when not in use too. I would look into renting, in the long run you would be better off.

[Lavrans]

Re: Building concrete foundation forms, what to treat/cover them with?

Form release. Yum.

[Norm Yeager]

Re: Building concrete foundation forms, what to treat/cover them with?

I've formed and poured my last two house foundations with full basements. It was well worth it from a cost and quality standpoint. (40 - 50 yards) Both times I used the Gates System of cam locks and 2x4's. When I was finished with the plyform I used it as subfloor and the 2xs for framing. Each sheet ends up with 14-13/16th holes in it, but since the finish floors were hardwood it didn't matter. The walls were much nicer than having a contractor do them since the plyform was new. In both cases I had wall contractors stop and look at the finished jobs and they commented that the job looked nicer than they could produce with their mutiple use forms. I used release agent on the forms each time and a mile of rebar. If I built another house and had the energy I'd do it again in a heartbeat.

[m beezo]

Re: Building concrete foundation forms, what to treat/cover them with?

For 10 years I worked for a rental yard here in St Louis and was the lead repair man for their concrete forms. We used a Baltic Birch plywood with a thin plastic coating on it. I can tell you that you might get by a few times without using a form release agent but not much more. Maybe even less if you are running a vibrator inside the forms which if you get over about 3 ft you need to do.

Not sure about making your own if you were going to use the plywood we sold. It is expensive, very hard material and tough on blades. I do not know what it costs to rent them but we used to rent them, provide a drawing showing which piece went where, how many snap ties you needed, how many wedge bolts. We would then deliever them to the jobsite if you needed it and pick them up when you were done. No storage for you. I thought the rent was something like 10% of the cost of the forms or less.

We rented Symons forms. Very heavy duty steel frames. Other systems are somewhat similiar but some have the larger aluminum panels so you have a few less pieces and seams. I have heard of Gates but do not recall the system.

Other thing if you really want the forms we used to sell used forms. But even the guys that owned the forms were coming to us for the few pieces that they did not have to make the occasional bay window, some odd ball offset, maybe a 10 ft pour instead of an 8 ft. I believe any system you start with you are married to it because the parts are not interchangable. Think cordless tools and batteries.

[dmwyatt]

Re: Building concrete foundation forms, what to treat/cover them with?

m_beezo: NuWay?

We bought our forms from them 15 or 20 years ago...

[David Meiland]

Re: Building concrete foundation forms, what to treat/cover them with?

Typical wall forms here are 1-1/8" HDO plywood with cleats and snap ties. You can get 1', 2', 3', and 4' wide, by 8' long. New cost is around $40 for a 2' x 8' piece. They are easy to set up and strip, and they stack nicely on a trailer or truck bed. You end up cutting some on every job, but not many, and they last a long time. I have seen guys make forms out of thinner plywood and 2x frames and always wondered why... maybe for very tall walls.

[m beezo]

Re: Building concrete foundation forms, what to treat/cover them with?

m_beezo: NuWay?

We bought our forms from them 15 or 20 years ago...

No it was Goedecke. NuWay was our competition. When I started there I was told I would probably never make it working in the yard since I had a college degree and did not drink coffee. Still have the degree and still don't drink coffee. I lasted 10 years, moved up from a truck loader to running a part of the repair shop with 6 guys to sometimes running the entire yard with about 20 guys. Not trying to toot my own horn but I was pretty proud of how I felt I helped the company. I left after being told things like I could be replaced with anyone that had worked at a McDonald's and it was not long before they tried that. Gave him a raise over what he got at McDonald's and nearly 20 years later he is now making what I made when I left there.

It was a good company and I left when the company got bought out and the climate changed shortly there after. It was still carrying the same things, selling to the same guys but the atmosphere changed from a family run business to just a business. I might have thought differently if I had been a business owner and knew some of the ins and outs of business but I stil think some of the tactics were not called for by the new owners. I have seen it happen in other places so I know it happens. But just because you come and buy the place I still think it is a bad thing to replace guys that have been with you for 20 years, were top salesmen with all the construction contacts to keep the company going and bring in your buddies from car salesmen to the deacon of your church just because they both needed a job. The car salesman did alright because he had sales down. The deacon rode on everyone's coat tails for at least 3 years and still did not have a clue.

The guy bought the company when I had been there about 7 years and we had just signed a union contract so he was stuck with us. The next contract he offered us a 75% reduction in pay, everyone a loss of 1 week of vacation which meant that new guys got no vacation until they had been there 2 years, loss of 5 sick days when we had 7. It did not fly with the guys and we were on strike for 9 months. Most of the guys went back to work somewhere along the way, crossed over the line. I did not really blame too many of them because so many of them had started right out of high school and it was the only job they knew. Many had taken their money and bought homes and with nothing else to do crossed to make house payments. I took the opportunity to get into construction and worked for about 2 years for other contractors trying to learn as much as I could. One or two bosses were fair teachers, one or two only wanted to see your head down and working hard. After that I started my own business and learned I needed to learn a lot quickly.

I know it has nothing to do with plywood forms but as you can see even after 20 years it still brings out a bit of feelings in me. Funny but I still go there for some items that are specific to certain concrete issues to pick up products if I am in their neighborhood. Otherwise it is NuWay.

[dave_k]

Re: Building concrete foundation forms, what to treat/cover them with?

Typical wall forms here are 1-1/8" HDO plywood with cleats and snap ties. You can get 1', 2', 3', and 4' wide, by 8' long. New cost is around $40 for a 2' x 8' piece. They are easy to set up and strip, and they stack nicely on a trailer or truck bed. You end up cutting some on every job, but not many, and they last a long time. I have seen guys make forms out of thinner plywood and 2x frames and always wondered why... maybe for very tall walls.

Are you talking about these forms? http://www.advanceconcreteform.com/forms.htm If you are there is no buying a single form. You have to buy a system. The ties have to line up. You need lots of corners, different width panels, fillers to make wall of different lengths and then you need to transport them. The small guys around here using these forms, running a single crew have upwards of $200k in forms and a boom truck.

The advantage of these forms is they are very fast to set up and cycle. They are also very durable. If you are going to do light foundations they are the most cost effective forming systems available.(locally anyway) Moderately expensive initial outlay but fast to cycle and many foundations out of them.

The disadvantage is they are expensive, single purpose (foundation walls) You can't heavily vibrate them so they are limited to light foundations.

Formply. I can form just about anything with formply and I mean anything. You can kerf it and curve it, twist it and build as big and as high as you can handle in a single pour. I can free form walls with snapties and walers, I can make up hand set panels. I can build mass foundations for machinery using coil ties and threaded rod. I can build suspended slabs, beams and columns. I can rent aluma beams and make crane or forklift set gang forms. I can build form that can take nearly any amount of concrete pressure or viberation and remain straight and true. If the panels are in good condition I can get superior quality finishes and straight, plumb structures built to the millimeter. As I recycle my form ply for different uses even the smallest pieces can be of use to me. To build my forms all I have to do is order ply and lumber from the lumber yard and have it delivered.

The disadvantages are that for foundation walls it's always going to take longer to build and cycle and you don't get nearly the number of pours out of them. You always waste a lot of lumber in cut up walers and braces. There is a lot more material to move. I look at buying formply as an expense, once the job is over it does go back to the yard but you always lose a large quantity of material every time you rework forms. Advance forms are an investment in a system. You never have to cut a thing. You can make custom fillers out of formply but you never touch your panels.

Now don't get me started on Peri http://www.peri-usa.com/products.cfm . It's amazing stuff but WAY too expensive for any of us to consider using. I'm supposed to be going on a course to learn to teach their systems in the near future. I'm going to enjoy it. I make my living as a trim carpenter but I've always loved doing concrete.

[dave_k]

Re: Building concrete foundation forms, what to treat/cover them with?

Both times I used the Gates System of cam locks and 2x4's.

I haven't seen cam locks and spyders(strongback clamps) in 30 years. They are the best waler clamps.

When I was finished with the plyform I used it as subfloor and the 2xs for framing.

We used to do that when I worked for my dad only back then it was 3/4" T&G SPF

The walls were much nicer than having a contractor do them since the plyform was new. In both cases I had wall contractors stop and look at the finished jobs and they commented that the job looked nicer than they could produce with their mutiple use forms.

If you're free forming with formply and walers that's always going to be the case vs a system form. They can be built straight as an arrow and accurate to a millimeter. If it's new ply and you vibrate the finish will turn out perfect.

[David Meiland]

Re: Building concrete foundation forms, what to treat/cover them with?

Dave, I'm just talking about form ply. That and the snap tie hardware is about all you need.

[Norm Yeager]

Re: Building concrete foundation forms, what to treat/cover them with?

I haven't seen cam locks and spyders(strongback clamps) in 40 years. They are the best waler clamps.
We used to do that when I worked for my dad only back then it was 3/4" T&G SPF If you're free forming with formply and walers that's always going to be the case vs a system form. They can be built straight as an arrow and accurate to a millimeter. If it's new ply and you vibrate the finish will turn out perfect.

Like many things I've done over the years I saw other projects and thought " I should be able to do that". I never did any major form jobs before I did that first basement.
I had an excellent salesman who had a lot of experience who came out and gave me advice on two occasions. He said it was the first time he'd ever seen a form carpenter use a block plane. His guidance was a big help but the Gates system was very user friendly.The 8' walls were poured to 4' then vibrated and then the second lift was poured before a cold joint formed. The salesman told me that the system was designed to pour 8' in one lift but he seldom told anyone that. I still would have poured it in two lifts. With a huge pump truck, barrel trucks and very little help on the job I couldn't afford a blowout.
The walls came out great with only very minor honeycombing under some basement windows. It was a simple blemish to fix. It helps to have a level footing because there's only about 3/4" of adjustment on that form without alot of additional work.

[ddolman]

Re: Building concrete foundation forms, what to treat/cover them with?

We use the gates camlock system here in Alberta a fair bit. It is not generally used for residential, but it is very common for light commercial. It is a fairly adapatable system and allows for sturdy formwork. I have only ever seen 3/4" formply used with this system and it seems to hold up fine. I would definately get paperfaced forms rather than oiled and edged. They will last much longer and give a nicer finish. We usually use form release on every job, but if it gets missed the odd time, it is ok. I understand your distaste for form release, but I dont know of any other options.

[dave_k]

Re: Building concrete foundation forms, what to treat/cover them with?

Dave, I'm just talking about form ply. That and the snap tie hardware is about all you need.

I've never seen formply that thick. can't be much fun slugging those around by yourself.