Quad Deck, Part 1


Posted on September 24, 2015 by


Quad-Deck is a product sold by Quad-Lock, an ICF (Insulated Concrete Forms) company. It is basically a flooring (or roofing) system that uses polystyrene as a form for concrete.  The panels click together and include steel beams so they can span greater distances (with less shoring) while supporting the wet concrete.  The concrete hardens to form a continuous floor over the panels and the panels are left in place as insulation.

Quad Deck

My unique earth sheltered home design includes a basement.  This increased the height of the walls holding back earth.  Structurally, I needed my floor to be a sheer plane that would prevent the earth from pushing in those walls by transferring the lateral loads right thru the house into the dirt on the other side.  The resulting compression would be well handled by a concrete floor. I just had to find the easiest way to build one.

I could have built a deck out of wood or steel panels supported by bracing and just poured concrete over that.  There are modular systems that work pretty well and are cost effective for rectangular buildings, but my curved shape would make it quite difficult and expensive.  Also, those systems generally produce a uniform concrete thickness, which adds to the expense.

ICFs had the advantage of being easy to setup and easy to trim.  They also use less concrete because they can form that stronger IBeam shape.  The insulation is also perfect for my in-floor radiant heating and helps with more consistent indoor temperatures and reduced sound transmission.

Unlike ICF building blocks, there are very few companies that make this sort of ICF floor system, just about the only other company with a similar product is “Lite-Deck”, but they had no distributors in my region.  AMDeck is a similar product that only comes in short pieces (32 inches long) so you don’t need to order custom lengths, but you need to place the steel joists separately and then place the Insulation over them and it just seemed like more could go wrong.

The Video

The Process

Pile of QuadDeck1) The quad deck panels are cut to length (according to a cut sheet I provided) in the factory and shipped to the site.

2) The installers (in my case, Dan and Brian), started by setting up scaffolding spaced across the floor. Beams were placed across the scaffolding and the scaffold legs were adjusted to level the beams across the space.

3) My curved walls required both ends of every piece to be shaped to fit.  This was done with a measuring tape and a saws-all.  Occasionally a big cutting wheel was used.


4) Each piece was pushed up against the previous piece before being screwed in place so that they would be held tightly together.  The screws were “toe-nailed” thru the wood shoring and into the steel reinforcement.


5) Spray foam was used to seal the gaps between the top edge of the wall and quad deck material.

6) Rebar was placed in the channel and across the quad deck according to the drawing.  Rebar chairs were used.

7) A perimeter form, plumbing, electrical, HVAC, radiant floor PEX, etc. were added later (next post).


In my region, it seemed like I pretty much had to go with QuadDeck if I wanted this sort of product. To make matters worse, QuadDeck only had one single installer in my region.  I asked for a quote on both the quad deck and the ICF walls of the garage.  The wall quote from this builder was not even in the top 3 and several times more expensive than doing FoxBlocks myself.  But they were the only quote for the Quad Deck, and I thought special bracing was needed, so I decided to go with them for that portion of the build.  The quote was for “Quad Deck install, labor and shoring rental.”  I called for further clarification and was told it would get the quad deck ready for the pour, but did not include the actual concrete or labor to pour and finish the floor.  I would need to call a separate contractor for that.  The price was high, but acceptable for a company with specialty experience and equipment, so I put them in my estimate.

Later that summer, after back-filling around the basement, it was time to get the quote updated and call the crew out.  I sent in pictures of the basement (including zoomed in shots of the edge of the wall), along with a cut-sheet and images from my 3D model, calculations from the QuadDeck manual (it is a pre-engineered product), etc.  They updated the quote, but said they wanted an engineering stamp before they would start work.

My engineer had retired (still young, but wanted to stay home with his kids), so I contacted the builder’s engineer.  He was willing to check and stamp my work and he was very affordable, but he was also very old (eighty something) and only worked face to face (no computers). I would need to take him drawings and he would hand calculate and stamp them if he approved.   There was a funny telephone episode where I was asking him his address (so I could google map it), but he just kept repeating how to get to his office via landmarks. Before I could get out there (he lived 4 hours away), he had a stroke and retired.  I didn’t want to pay a new engineer to learn about QuadDeck, so I began a search for someone with experience.  The builder wasn’t much help.  I even called quad-lock company headquarters and they just forwarded my request back to the builder.  I called QuadDeck back a few times and asked for other regions until I eventually found an Engineering company in the southwest that was licensed to stamp a drawing in Michigan.  It ended up adding a surprise $1200 to my estimated cost, but may have saved me some money because my version would have used twice as much rebar (I was being conservative with the Quad Deck load calculations).

I still couldn’t schedule the builder to come out.  I tried to go around him, but it turned out he was also the only builder in the surrounding 4 states.  He had a monopoly and ran his business that way.

Eventually, we got the quad deck panels ordered.  I knew it would take weeks for my order to be cut and then delivered.  They were supposed to call me with a delivery time 24 hours in advance so I could organize to unload.  Instead I got an annoyed call from the driver at 6:00 in the morning wondering why there was no one at the building site.  Surprise, my 10-year-old and I hopped in my car and drove the hour out to the property, but there was no way to organize any other help in that short time.  When I got there a little after 7:00 AM, there was a large 18 wheeler trailer full of QuadDeck planks waiting for me.  It was the closed in kind with big double doors at the back, so I could not unload with my fork lift.  The panels were stacked to the roof and would need to be removed by hand, slid out one at a time.  I had to get a 13 ft ladder just to reach the panels.  The driver was impatient, so David and I got to work without setting up the camera.  The driver complained that we were taking too long, so I told him that he could have called to let us know he was coming (as he was supposed to do) or he could help.  He helped a little with a couple of pieces that David could not physically lift, but generally speaking, he just paced back and forth.  Eventually we got them all out of the truck and the driver shook David’s hand before he left.  I think he was impressed with David, but was also still pretty annoyed with me for not having a real crew.

We used the SkidSteer to move the blocks up behind the house and stacked them and covered them with a tarp…  And then waited.  Every few weeks, the builder made up some excuse and moved the date back.  The list of back and forth texts is quite ridiculous. Eventually, 3 months later, he said he would be able to slot me in before the end of Sept (one week away).  He asked if I had the rebar on site, I did.  He asked if I had the full list of building materials he needed…  I had no idea what he was talking about.  He sent me a list, which added up to $1700.  Surprise!  The list included 4×6 beams, 35 lbs worth of screws, 3/4 inch plywood, 2x4s, 2x6s, a case of spray foam, anchor bolts, etc. I called him and asked if he was planning to build the shoring?  I was obviously annoyed, which annoyed him and he said we could just call off the whole thing and I could look for another builder.

Of course, I already had the material on site and he knew he was the only builder within 1000 miles that had ever installed this stuff before…  I gave in and we proceeded.  He then told me that his quote did not include the perimeter forms that would also be needed before we poured, but he could do that for an extra cost.  I was so annoyed, I didn’t even want to discuss the extra costs or argue that he never mentioned this before, so I told him I would take care of that myself.

I asked how many days it would take for what was included in the quote, he said 6 or 7 days for a crew of 3 people.

Anyway, as you can see from the video, it took 1 day just to set up the shoring (which turned out to be regular scaffolding and my 4×6 beams, leveled).  Then 2 days to put in the quad deck.  There was also a short 4th day of just a couple of hours when they finished the quad deck off and were gone by 9:00 AM to work on pouring some other wall somewhere else. Then the last day was just putting in rebar and spray foaming. The main boss never even made it out to the property.

After the job was done, he sent a final bill that included about 2000$ extra costs for “unexpected extra work” including putting in rebar and spray foam and “gasoline for the generator”, etc.  I was sick of the surprises and fought him on most of it.  He kept asking me to “meet him half way”. Instead I went thru my emails, texts and time-stamped-timelapse photos and wrote up what could easily have been a trial defense.  For instance, I pointed out that he had estimated 7 days for 3 people, but got the job done in 4 days with mostly 2 people, how could he justify “extra costs”?  He eventually gave in on most of the bogus extra charges, but still got his “36$ for gasoline for the generator”.  I just wanted to move on.

Then he hit me with the scaffold rental.  He wanted several thousand for that.  I told him that his quote said “labor and scaffold rental”.  He said that was just the first 2 weeks, I had kept the scaffolding for 3 weeks longer than that to finish getting it ready for pour and then leaving the scaffolding in for 2 weeks while the floor set.  He wanted $15 per unit for those 3 weeks.  I eventually agreed, but then he defined the units as half sets (so twice the cost).  Arg!  long story short, I ended up paying an additional 810$ to rent that scaffolding for 3 weeks.  For perspective, I paid $1200 to buy my other 5 sets of scaffolding, and that included 6 decks, 8 wheels, outriggers, a grouser bar, etc.

Anyway, as much as I liked the idea of QuadDeck, I would never work with that builder again.  I have some quad deck left for the roof of the mezzanine.  I plan to install it myself.

Bonus fun facts…

IMG_20151031_170822546 (Medium)1) The scaffolding that I rented has been stacked nicely and ready for pickup for almost 4 months with no responses to my monthly texts to the builder to come and pick ’em up.  You will see it in the background of various other videos ;^)  It was actually quite labor intensive to remove it from the basement (next video), so I hope the builder appreciates that that free labor.  I wonder if I could surprise him with storage fees?

2) At the end of each day, the guys did a great job cleaning up the site.  They used a leaf mulcher to suck up and bag the little broken bits of Styrofoam so they wouldn’t blow all over the place and they carefully stacked the other trash.


PiggyBankStressedThe original quote was about 4$/sqft for quad deck materials.  That turned into 6$ by the time we placed the order (including freight).  Then another $7/sqft for labor and shoring rental.  I also budgeted about $1 for rebar and 2$ for concrete, plus 3$ for labor to pour and finish the floor.  Then I had the surprise of just over 1$ for engineering plus just under 2$ for extra materials (some of which I was able to return unused and much of which I will reuse elsewhere in the build).  Then, finally, that ridiculous “additional” scaffold rental at the end, which divided out to just under 1$/sqft.  That comes to about ~22$/sqft by the time we were done.  Quite a bit over-budget, but survivable.

Response to Quad Deck, Part 1

  1. Thanks so much Simon for taking the time to share this information. You’ve done a great job at documenting the entire project to date. Keep up the good work and best wishes on a successful completion!

  2. Pingback: My Homepage

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